Building Air Quality
AGuide for Building Owners and Facility Managers
U.S. Environmental Protection Agency
Office of Air and Radiation
Office of Atmospheric and Indoor Air Programs
Indoor Air Division
U.S. Department of Health and Human Services
Public Health Service
Centers for Disease Control
National Institute for Occupational Safety and Health
CENTERS FOR DISEASE CONTROL
December 1991
For sale by the U.S. Government Printing Office
Superintendent of Documents, Mail Stop: SSOP, Washington, DC 20402-9328
ISBN 0-16-035919-8
Printed on Recycled Paper
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Contents
Foreword vii
Note to Building Owners and Facility Managers ix
Acknowledgements xiii
TAB I: BASICS
Section 1: About This Document 1
Section 2: Factors Affecting Indoor Air Quality 5
Sources of Indoor Air Contaminants 5
HVAC System Design and Operation 6
Pollutant Pathways and Driving Forces 9
Building Occupants 10
Section 3: Effective Communication 13
Communicating to Prevent IAQ Problems 13
Communicating to Resolve IAQ Problems 15
TAB II: PREVENTING IAQ PROBLEMS
Section 4: Developing an IAQ Profile 19
Skills Required to Create an IAQ Profile 20
Steps in an IAQ Profile 21
Section 5: Managing Buildings for Good IAQ 31
Developing an IAQ Management Plan 31
TAB III: RESOLVING IAQ PROBLEMS
Section 6: Diagnosing IAQ Problems 45
Overview: Conducting an IAQ Investigation 46
Initial Walkthrough 47
Collecting Additional Information 49
Collecting Information about Occupant Complaints 50
Using the Occupant Data 53
Collecting Information about the HVAC System 57
Using the HVAC System Data 62
Collecting Information about Pollutant Pathways and Driving Forces 68
Using Pollutant Pathway Data 70
Collecting Information on Pollutant Sources 72
Using Pollutant Source Data 74
Contents iii
-------
Sampling Ak for Contaminants and Indicators < 74
Complaints Due to Conditions Other Than Poor Air Quality 77
Forming and Testing Hypotheses 78
Section 7: Mitigating IAQ Problems 81
Background: Controlling Indoor Ak Problems 81
Sample Problems and Solutions 86
Judging Proposed Mitigation Designs and Thek Success 102
Section 8: Hiring Professional Assistance to Solve an IAQ Problem 105
Make Sure That Thek Approach Fits Your Needs 105
Selection Criteria 106
TAB IV: APPENDICES
Appendix A: Common IAQ Measurements - A General Guide 109
Overview of Sampling Devices 109
Simple Ventilation/Comfort Indications 110
Ak Contaminant Concentrations 115
Appendix B: HVAC Systems and Indoor Air Quality 121
Background 121
Types of HVAC Systems 122
Basic Components of an HVAC System 123
ASHRAE Standards and Guidelines 137
Appendix C: Moisture, Mold and Mildew 141
Background on Relative Humidity, Vapor Pressure, and Condensation 141
Taking Steps to Reduce Moisture 143
Identifying and Correcting Common Problems From Mold and Mildew 145
Appendix D: Asbestos 147
EPA and NIOSH Positions on Asbestos 148
Programs for Managing Asbestos In-Place 149
Where to Go for Additional Information 150
Appendix E: Radon 151
Building Measurement, Diagnosis and Remediation 151
Where To Go for Additional Information 152
Appendix F: Glossary and Acronyms 153
Appendix G: Resources 157
Federal Agencies with Major IAQ Responsibilities 157
Other Federal Agencies with Indoor Ak Responsibilities 160
State and Local Agencies 160
Private Sector Contacts 161
Publications 164
Training 167
iv Contents
-------
TAB V: INDOOR AIR QUALITY FORMS
IAQ Management Checklist , 171
Pollutant Pathway Record For IAQ Profiles .-.; 175
Zone/Room Record 177
Ventilation Worksheet ..179
Indoor Air Quality Complaint Form 181
Incident Log 183
Occupant Interview 185
Occupant Diary ..187
Log of Activities and System Operation 189
HVAC ChecklistShort Form .:;... 191
HVAC ChecklistLong Form 195
Pollutant Pathway Form For Investigations .; ....211
Pollutant and Source Inventory 213
Chemical Inventory 221
Hypothesis Form .223
This document is in the public domain. It may be reproduced in whole or in part by an individual or organization without permission. If it
is reproduced, however, EPA and NIOSH would appreciate knowing how it is used. Write the Indoor Air Division (ANR-445W), Office
of Air and Radiation, U.S. Environmental Protection Agency, Washington, DC 20460.
Contents v
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Page Intentionally Blank
if.
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Foreword
In the past two decades, the number of
people requesting information and assis-
tance on health and comfort concerns
related to indoor air quality from the U.S.
Environmental Protection Agency (EPA)
and the National Institute for Occupational
Safety and Health (NIOSH) has risen
steadily. Although many studies on indoor
air quality have been reported in technical
publications and proceedings during these
years, little indoor air-related information
has been targeted at owners and facility
managers of public and commercial
buildings who are the people in the best
position to prevent and resolve indoor air
problems.
In recognition of the need for practical
indoor air quality advice for building
owners and facility managers, EPA and
NIOSH decided to work jointly to produce
written guidance on preventing, identify-
ing, and correcting indoor air quality
problems. The distinct perspectives of the
two agencies are reflected in this docu-
ment.
Since 1971, NIOSH has conducted
more than 600 indoor air quality investiga-
tions in office (non-industrial, non-
residential) buildings under the Health
Hazard Evaluation Program. Over time,
NIOSH has developed a "solution-
oriented" approach to these investigations.
This document draws extensively on the
experience of NIOSH in investigating and
correcting indoor air quality problems in
these types of buildings.
In 1986, Congress mandated that EPA
conduct research and develop information
on indoor air quality. To carry out its
information dissemination responsibilities,
EPA's Indoor Air Division has produced a
number of publications which have been
distributed to a wide range of audiences
and will launch an indoor air quality
information clearinghouse in 1992. In
addition, the Indoor Air Division is
developing several guidance documents on
building design and management practices.
This publication is part of that effort.
The guidance presented here is based
on what is known and generally accepted
at this time in the relevant fields of
building science and indoor air quality.
EPA and NIOSH anticipate that this
document may later be revised to include
more detailed guidance as research
continues and our knowledge grows. In
the meantime, building owners and facility
managers can use the resources listed in
Appendix G to supplement and update the
information presented here.
Foreword vii
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Note to Building Owners and
Facility Managers
rom marketing and negotiating
and maintenance contracts to planning for
future expansion, operating a commercial
or public building is a complex process
that leaves you little time for unnecessary
activities. Working with your facility staff,
you an effort to provide a pleasant
setting and are accustomed to dealing
with occupant complaints about room
temperature, noise, plumbing system
problems, and other elements of the
building environment
A healthy indoor environment is one in
which the surroundings contribute to
productivity, comfort, and a sense of health
and well being. The indoor air is free from
significant levels of odors, dust and con-
taminants and circulates to prevent
stuffiness without creating drafts. Tem-
perature and humidity are appropriate to
the season and to the clothing and activity
of the building occupants. There is enough
light to illuminate work surfaces without
creating glare and noise levels do not
interfere with activities. Sanitation,
drinking water, fire protection, and other
factors affecting health and safety are well-
planned and properly managed.
Good air quality is an important
component of a healthy indoor environ-
ment. For the purposes of ibis document,
the definition of good indoor air quality
includes;
introduction and distribution of adequate
ventilation air
control of airborne contaminants
maintenance of acceptable temperature
and relative humidity
A practical guide to indoor air quality
(IAQ) cannot overlook temperature and
humidity, because thermal comfort
concerns underlie many complaints about
"poor air quality." Furthermore, tempera-
turd and humidity are among the many
factors that affect indoor contaminant
levels.
It is important to remember that while
occupant complaints may be related to
time at work, they may not necessarily be
due to Inequality of the air. Other factors
such as noise, lighting, ergonomic stressors
(work station and task design), and job-
related psychosocial stressors can
individually and in combination
contribute to the complaints. These
problems are briefly addressed in this
document.
Good indoor air quality enhances
occupant health, comfort, and workplace
productivity. Rental properties can gain a
marketing advantage if they are known to
offer a healthy and pleasant indoor envi-
ronment. Failure to respond promptly and
effectively to IAQ problems can have
consequences such as:
increasing health problems such as
cough, eye irritation, headache, and
allergic reactions, and, in some rare
cases, resulting in life-threatening
conditions (e.g., Legionnaire's disease,
carbon monoxide poisoning)
reducing productivity due to discomfort
or increased absenteeism
accelerating deterioration of furnishings
and equipment
straining relations between landlords and
tenants, employers and employees
creating negative publicity that could put
rental properties at a competitive
disadvantage
opening potential liability problems
{Note: msurance policies tend to exclude
pollution-related claims)
Note to Building Owners and Facility Managers ix
-------
Rcovision of good air quality requires
conscientious effort by both building staff
and occupants. The commitment to
address IAQ problems starts with the
building owner or facility manager, the
person who has an overview of the
organization, sets policy, and assigns staff
responsibilities. You have the authority to
see that an IAQ policy is articulated and
carried out, the ability to identify staff with
skills that enable them to react promptly
and effectively to complaints, and the
incentive to initiate a program that will
prevent indoor air problems in the future.
As you decide how best to respond to the
challenge of preventing and resolving
indoor air quality problems in your
building, it wiE be helpful to keep in mind
the following thoughts:
It is Important to establish a process
that encourages an active exchange of
information.
Without an open communications policy,
an atmosphere of distrust may be created
that complicates your efforts to diagnose
and correct problems.
FaciUty staff are in a position to notice
malfunctioning equipment or accidental
events that could produce indoor air
quality problems.
They can play a critical role in identifying
problem situations and averting IAQ
crises. On the other hand, if staff are not
aware of IAQ issues, their activities can
also create indoor air quality problems.
Facility staff are often instructed to keep
energy costs to a minimum.
Changes to building operation intended to
save energy have sometimes contributed to
IAQ problems (for example, by reducing
the flow of outdoor ventilation air without
taking action to maintain the quality of the
recirculated air). The correction of IAQ
problems has sometimes led to reduced
energy use due to the efficiency associated
with a cleaner and better controlled
heating, ventilation, and air conditioning
(HVAC) system. The energy needed to
condition and distribute ventilation air is
only a small part of total building energy
consumption and is far overshadowed by
other operating costs (such as personnel).
Attempting to limit operating costs by
reducing ventilation can be a false
economy, if it leads to problems such as
increased occupant complaints, reduced
productivity, and absenteeism.
Every complaint merits a response,
Many indoor air quality problems are not
difficult to correct and can be solved with
in-house expertise. However, gathering
relevant information about the problem
and identifying appropriate corrective
actions are likely to require a coordinated
effort by people with a variety of skills.
An indoor air quality problem may
be the direct or indirect result of an
apparently minor modification,
Actions such as the placement of interior
room dividers, the introduction of new
office equipment, and personal activities
such as cooking can have an impact on
indoor air quality. Communication
between building management and
building occupants regarding their respec-
tive responsibilities is a critical element in
the management of indoor air quality.
Indoor air quality in a targe building is
the product of multiple influences, and
attempts to bring problems under control
do not always produce the expected result.
Some indoor air quality problems are
complex and may require the assistance of
outside professionals. When contracting
for services, you need to be an Wormed
client to avoid unnecessary costs and
delays in solving the problem.
X Note to Building Owners and Facility Managers
-------
If there is reason to believe that an IAQ
problem may have serious health implica-
tions, appropriate experts such as occupa-
tional physicians, industrial hygienists,
and mechanical engineers should be ,
called in as soon as possible.
In-house investigations by non-profession-
als are not recommended in such cases
(e.g., if individuals are being hospitalized
because of exposure inside the building).
Public and commercial buildings can
present a wide range of IAQ problems.
The variety of unique features in their
design and usage (e.g., apartment build-
ings, hospitals, schools, shopping malls)
make a wide range of IAQ problems pos-
sible. In apartment buildings, for example,
each residential unit can produce cooking
odors and the operation of kitchen exhaust
fans is generally outside the control of
building management. The basic informa-
tion and problem-solving processes in this
guide can be applied, with necessary adap-
tations, to a wide range of building types.
This document was written to be a use-
ful resource for you and your staff in pre-
venting and resolving occupants* com-
plaints that may be related in some way to
the quality of the indoor air. It provides
background information followed by
"how-to" guidance for you and your in-
house staff. The practical problem-solving
techniques it describes have been applied
successfully by NIOSH and other investi-
gators. If complaints are not resolved after
careful application of this guidance, out-
side help will probably be needed. Infor-
mation on possible sources of outside help
is included. As you read this document, or
turn it over to your staff to implement,
EPA and NIOSH urge you to maintain a
personal involvement in this issue.
Note to Building Owners and Facility Managers xi
-------
I to help building owners and facility managers get
lra^juainted with examples of JAQ problem indicators and associated
responses. Some IAQ probjerr^situations require immediate action.
.Qther problems are less urgent, but all merit a response.
lAJBtanilrinjq^ TTherehave been complaints of hmd>_ Carbon .monoxide, poisoning is a
tartfoft "^ " achซSj"naus"ea, and combustion ogors.,.^ . possibility. Investigate sources of
"'""' " "" -.ซ....- .' ปซ..*.. - :away
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This is a potentially life-threatening
jHnesa,Request Health Department
assistance in. determining whether
rป3&ซ^B^^ptls^ป.l'iMiปซซซซiซปiซ>-ปซซ*.''''*<**ซi"*Jซ'-
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^a&sr "
|f d,?rj)p carpeting cannot be lifted and
thoroujhjj? dried within a short time,
might need to be discarded. Proper
S,-*,St,ป., rซ~- ; -,- -. r
ng and disinfection procedures
^8^41& prevent the growth
I^J2^,mlj^งw Uif * pould cause
t^rious jn,d(xrr air quality problems.
^^^.^.^-ftlteS^lfetfioJltYstem
reveals an accumulation of slims and
' mold. There have been no health
- complaints suggesting IAQ problems.
Inadequately maintained humidifiers
.^ can promote the growth of biological
contaminants. Clean equipment
thoroughly, and consider modifying
practices.
r.Ajroupjrfoccupante has discovered
J jthaj tt^y^sha^e_commjgnjymptoms of _
adaches, eye irritation, and respira-
The_gymptoms described suggest an
IAQ problem that is not life-threaten-
ing, but It would be wise to respond
., promptly.
*
"SSHSir
_2 ,ne!?L _. ___ VfelatJIe.compounds emitted by the
jfurnffiire^oi; carpซfingj,_ new furnishings could be causing the
_ ^a,.,.,,.^ . . ^^^ ^ complaints.
v~ซBPซX^^-:--tsWปป*^-^i'^'vr-ISป"---- - ' ' ..-.....:
tat some The orily way to determine the indoor
(sjrii tjte area have high indoor radon concentrajtion ma given
re js to test in appropriate
^rK. *r^i"i,vtj3 ^งS3SHIii^^ ' tyT'SV-^ JT "" ' ' "" "^
/^bestos,can be positively identified
only by laboratory analysis.
xii Note to Building Owners and Facility Managers
-------
Acknowledgements
I he development of this document,
Building Air Quality: A Guide for
Building Owners and Facility Managers,
has been a joint undertaking of the
Indoor Air Division in the Office of
Atmospheric and Indoor Air Programs of
the United States Environmental
Protection Agency and the National
Institute for Occupational Safety and
Health, The document was prepared
under the direction of Robert Axelrad,
Director, EPA Indoor Air Division and
Philip J. Bierbaum, Director, NIOSH
Division of Physical Sciences and
Engineering.
EPA and NIOSH appreciate the time
that many organizations and individuals
took to share ideas, discuss their own
practical experiences, and review many
drafts of this document. Many of the
ideas raised by these reviewers have
been incorporated into this document.
Two people,had primary responsibility
for developing the content and format of
the document Elizabeth Agle, the EPA
project manager, developed the structure
of the document, assembled the teams of
contributors and reviewers, and provided
direction and untiring support as the pro-
ject came to fruition. Susan Galbraith,
Cogito Technical Services, served as the
principal writer. She brought to the task
both considerable writing skills and a
basic understanding of how buildings
operate that proved invaluable through-
out the process of conceptualizing and
creating this document.
EPA and NIOSH gratefully acknowl-
edge the important contributions of Terry
Brennan, Camroden Associates; Ed
Light, Pathway Diagnostics; and William
A. Turner, The H. L. Turner Group, who
served as the team of core technical
advisors for this document.. These, indi-
viduals contributed a substantial amount of
written material and thoughtful comments
on the many drafts and, most importantly,
their considerable practical experience in
identifying and resolving indoor air quality
problems. Joseph Lstiburek, Building
Science Corporation, contributed much of
the material on the problem of moisture.
EPA and NIOSH particularly wish to thank
the staff of The Charles E. Smith Compa-
nies who reviewed numerous drafts of the
document and made invaluable comments
from a building management perspective.
The photographs were donated by: Terry
Brennan, Camroden Associates; Michael
Crandall, NIOSH; Ed Light, Pathway
Diagnostics; Joseph Lstiburek, Building
Science Corporation; Phil Morey, Clayton
Environmental Services; Tedd Nathanson,
Public Works Canada; Robert Olcerst,
Brujos Scientific Inc.; Stan Salisbury,
NIOSH; William A. Turner, The H. L.
Turner Group; and Kenneth Wallingford,
NIOSH. Additional slides came from the
NIOSH Health Hazard Evaluation Program
and from the Occupational Safety and
Health Administration.
A, large number of people within both
EPA and NIOSH commented on the drafts
of the document. EPA and NIOSH
recognize the following staff for their
particular contributions: John Girman,
Elissa Feldman, Pauline Johnston, Sue
Perlin, David Mudarri, Jack Primack, Bob
Thompson, Kevin Teichman, Charles
Truchillo, and Jim Wilson, EPA; and
Michael Crandall, Jerome Hesch, Richard
Gorman, Joseph Hurrell, Pantelis Rentes
and Mitchell Singal, NIOSH.
Acknowledgements xiii
-------
The draft document was widely circu-
lated for review outside these agencies.
EPA and NIOSH thank the following
individuals who reviewed all or part of the
document and submitted comments:
Allen C. Abend
Maryland Department of Education
Charles A. Achilles
Institute of Real Estate Management
Henry A, Anderson
Wisconsin Department of Health and
Social Services
David W. Bearg
Life Energy Associates
W. David Bevirt
Sheet Metal and Air Conditioning
Contractors Association
Barbara Billauer
International Council of Shopping Centers
Bob Bockholt
National Apartment Association
H, E. Burroughs
H. E. Burroughs & Associates, Inc.
Harriet Burge
University of Michigan Medical Center
Paul A. Gammer
Business Council on Indoor Air
James L, Coggins
Energy Applications, Inc.
Geraldine V. Cox
Chemical Manufacturers Association
Earon S. Davis
Environmental Health Consultant
John E. DiFazio, Jr.
Chemical Specialties Manufacturers
Association
James C. Dinegar
Building Owners and Managers
Association International
Stephen D. Driesler
National Association of Realtors
Sandra Eberle
U.S. Consumer Product Safety
Commission
Paul C. Fiduccia
International Council of Shopping Centers
Richard B. Gammage
Oak Ridge National Laboratory
Matthew GiUen
Occupational Health Foundation
William H. Groan
Hardwood Plywood Manufacturers
Association
Shirley J. Hansen
Hansen Associates
Steven B. Hayward
Indoor Air Quality Program, California
Department of Health Services
John Henshaw
American Industrial Hygiene Association
Bion Howard
Alliance to Save Energy
W. T. Irwin
CertainTeed Corporation
Paul Jacobetz
Briiel & Kjaer Instruments, Inc.
William D.Kelley
American Conference of Governmental
Industrial Hygienists, Inc.
Jay Kirihara
The Trane Company
Daniel A. La Hart
Maryland Department of the Environment
Mary Lamielle
National Center for Environmental
Health Strategies
Ellen Larson
Air Conditioning Contractors of America
David Lee
Association of Local Air PoEution
Control Officials
Eugene L. Lehr
U.S. Department of Transportation
Hal Levin
Indoor Air Bulletin
William H. MeCredie
National Particleboard Association
Jean P. Mateson
Mateson Environmental Management, Inc.
Keith Mestrieh
Food and Allied Service Trades
Eugene M. Moreau
Indoor Air Program,
Maine Department of Human Services
Niren L. Nagda
GEOMET Technologies, Inc.
Fred Nelson
National Foundation for the
Chemically Hypersensitive
xlv Acknowledgements
-------
Laura Oatman
Indoor Air Quality Program,
Minnesota Department of Health
Andrew Persfly
National Institute for Standards and
Technology
George R. Phelps
Thermal Insulation Manufacturers
Association, Inc.
William A. Pugsley
Lincoln-Lancaster County Health
Department (Nebraska)
G.S, Rajhans
Ontario Ministry of Labour
Susan Rose
U.S. Department of Energy
Steven A. Scala ,
U.S. Public Health Service
James Sharpe
The Charles E. Smith Companies
Richard J. Shaughnessy,,III
Indoor Air Program, University of Tulsa
Thomas J. Shepich
Occupational Safety and Health
Administration
Henry J, Stager
General Services Administration
Philip A. Squair
Air-Conditioning and Refrigeration
Institute
JofanH. Stratton
Sheet Metal and Air Conditioning
Contractors Association
Kenneth M. Sufka
Associated Air Balance Council
John M. Talbott
U.S. Department of Energy
Simon Turner
Healthy Buildings International, Inc.
Richard, A. Versen .
Manville Technical Center
Davidge Warfield
National Air Duct Cleaners Association
Lewis Weiestoek
Forsy th County Environmental Affairs
Department (Georgia)
John F.Welch
Safe Buildings Alliance
Arthur E. Wheeler
Wheeler Engineering Company
Jim H. White
Canada Mortgage and Housing
Corporation
W. Curtis White
Aegis Environmental Management, Inc.
Alexander J. Wilhnan
National Energy Management Institute
Myra Winfield
Veterans Administration (Texas)
James E. Woods
College of Architecture and Urban Studies,
Virginia Polytechnic Institute
Rita Cohen, of ICF, Inc., assisted in the
project management for the development
of this document. Marie O'Neill, of The
Bruce Company, provided editorial and
coordination assistance, EPA and NIOSH
extend special thanks to Linda Berns,
Terry Savage, and others at the firm of
Berns and Kay, Ltd. for their effort and
enthusiasm in designing and producing the
document under tight deadlines.
Acknowledgements XV
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Page Intentionally Blank
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About This Document
BEFORE YOU BEGIN
The goal of this guidance document is to
help you prevent indoor air quality
problems in your building and resolve such
problems promptly if they do arise. It
recommends practical actions that can be
carried out by facility staff, outside
contractors, or both. The document will
help you to integrate lAQ-related activities
into your existing organization and identify
which of your staff have the necessary
skills to carry out those activities.
This is a long document. It would be
convenient if all of the ideas it contains
could be summed up in a few short
recommendations, such as: "check for
underventilation" and "isolate pollutant
sources." However, such statements
would only be helpful to people who are
already familiar with indoor air quality
concerns. If the owner's manual for your
car said to check your pollution control
valves every year, but didn't say how to
find out whether they were working
properly, you would need either a more
detailed manual or the money to hire a
mechanic. Don't be discouraged by the
number of pages in your hands. Once you
begin to understand the factors that
influence indoor air quality in your
building, you can move from section to
section, reading what you need to know at
the moment and leaving the rest until later.
Some Basic Assumptions
EPA and NIOSH recognize that many
factors influence how an individual owner
or manager can put the information in this
guide to use. The skills of facility staff and
the uses of the, building can vary widely,
affecting the types of IAQ problems that
are likely to arise and the most effective
approach to resolving those problems.
The assumptions used in preparing this
guide include:
The expense and effort required to
prevent most IAQ problems is much less
than the expense and effort required to
resolve problems after they develop.
* Many IAQ problems can be prevented
by educating facility management, staff,
and occupants about the factors that
create such problems. When IAQ
problems do arise, they can often be
resolved using skills that are available
in-house.
The basic issues and activities involved
in preventing and resolving IAQ prob-
lems are similar for buildings of many
different designs and uses.
If outside assistance is needed to solve
an IAQ problem, the best results will be
achieved if building owners'and manag-
ers are informed consumers.
How this Guide is Organized
This guide is divided into topic areas
marked by tabs. Tab I marks introductory
material directed toward all users of the
document. Tab H is directed to building
owners and facility managers who do not
have a current IAQ problem and want to
prevent such problems from arising. If you
currently have an indoor air quality
problem, Tab HI provides guidance to
help resolve that problem. The appendices
marked by Tab IV present information
that may not be critical to resolving most
indoor air quality problems but could be
useful reading for additional background
About This Document 1
-------
on major IAQ topics. Abbreviated sample
forms are included throughout the text so
that readers can see what types of informa-
tion can be collected using the forms pro-
vided in this document. Tab V contains
the complete forms discussed in the text.
These can be photocopied for use by you
and your staff.
As you read this document, you will find
that some guidance points are repeated,
This was intentional, as it allows .you to
use the sections on prevention, diagnosis,
and mitigation as ''stand-alone" guides,
Tab I: Basics
Section 2: Factors Affecting Indoor Air
Quality
Indoor air quality is not a simple, easily
defined concept like a desk or a leaky
faucet. It is a constantly changing interac-
tion of a complex set of factors. Pour of
the most important elements involved in
the development of indoor air quality
problems are: a source of odors or
contaminants; a problem with the design or
operation of the HVAC system; a pathway
between the source and the location of the
complaint; and the building occupants.
Read Section 2 for an introduction to the
factors that influence indoor air quality. A
basic understanding of these factors is
critical to investigating and resolving IAQ
problems.
Section 3: Effective Communication
An effective communication system helps
facility managers, staff, contractors, and
occupants to clarify their responsibilities
and cooperate in identifying potential IAQ
problems. Building occupants can be
valuable allies in resolving indoor air qual-
ity problems. On the other hand, even
small problems can have disruptive and
potentially costly consequences if occu-
pants become frustrated and mistrustful.
Effective communication is the key to
cooperative problem-solving.
Good communication can be promoted
through a group that represents all of the
interested parties in the building. Many
organizations have health and safety com-
mittees that can fill this role. Section 3
suggests ways to work productively with
building occupants to prevent IAQ prob-
lems and to maintain good communication
during IAQ investigations.
Tab II; Preventing IAQ
Problems
Section 4: Developing an IAQ Profile
An IAQ profile is a "picture" of building
conditions from the perspective of indoor
air quality. A review of construction and
operating records, combined with an
inspection of building conditions, helps to
reveal potential indoor air problems and
identify building areas that require special
attention to prevent problems in the future.
Baseline data collected for the IAQ profile
can facilitate later investigations, should
problems arise. Section 4 suggests a three-
stage approach to developing an IAQ
profile and describes the products of each
stage.
Section 5: Managing Buildings for Good
IAQ
Many indoor air problems can be pre-
vented by following common sense
recommendations, such as: maintain good
sanitation, provide adequate ventilation,
and isolate pollutant sources, Other
preventive measures may require a careful
review of job descriptions, contracts,
supplies, and schedules. It is important to
designate an IAQ manager to bear respon-
sibility for coordinating the effort in your
building. Section 5 discusses key elements
to include in your IAQ management plan.
Tab III; Resolving IAQ Problems
Section 6: Diagnosing IAQ Problems
Most IAQ investigations begin in response
to a complaint from one or more building
2 Section 1
-------
occupants. IAQ complaints can affect
entire buildings or be limited to areas as
small as an individual work station. The
goal of the investigation is to resolve the
complaint without causing other problems.
Section 6 describes a variety of informa-
tion-gathering strategies used to identify
the cause of an IAQ problem. This section
provides suggestions for in-house staff
who have been given the responsibility of
investigating the problem. It will also help
building management to understand and
oversee the activities of any outside
professionals who may be brought in to
assist in the investigation.
Section 7; Mitigating IAQ Problems
The basic approaches to mitigating indoor
air quality problems are; control of
pollutant sources; modifications to the
ventilation system; air cleaning; and
control of exposures to occupants. Suc-
cessful mitigation often involves a combi-
nation of these techniques.
Section 7 provides criteria for judging
potential mitigation strategies and for
determining whether a problem has been
solved. It includes brief descriptions of
common indoor air quality problems and
possible solutions.
Section 8: Hiring Professional Assis-
tance to Solve an IAQ Problem
Indoor air quality is an emerging and
interdisciplinary field. Section 8 provides
guidance in hiring professional assistance
if you decide that outside expertise is
needed to determine the cause of an IAQ
problem.
Tab IV: Appendices
Appendix A: Common IAQ
Measurements A General Guide
Appendix A describes measurement
techniques that are commonly used for
IAQ investigations. If you are responsible
for developing an IAQ profile or investi-
gating an IAQ complaint, Appendix A
provides suggestions for collecting and
interpreting information on: temperature
and humidity; airflow patterns; carbon
dioxide; ventilation (outdoor) air quanti-
ties; and commonly measured environmen-
tal contaminants.
Appendix B: HVAC Systems and IAQ
Appendix B presents basic information on
HVAC system designs and components
and their effects on indoor air quality.
This appendix is designed to accompany
the HVAC Checklists in Tab V.
Appendix C: Moisture, Mold and
Mildew
Appendix C discusses indoor moisture and
its relationship to mold and mildew
growth. The role of humidity in creating
mold and mildew problems is often
misunderstood because relative humidity
readings taken in the breathing zone of an
occupied space give little indication of
conditions at the wall and ceiling surfaces
or in the wall cavities. This appendix
describes ways in which to evaluate how
moisture may be causing indoor air quality
problems and how successful different
mitigation measures may be in reducing
those problems.
Appendix D: Asbestos
Appendix D is a brief discussion of
asbestos. If asbestos is a concern in your
building, this appendix and the Appendix G
section will direct you to sources of
detailed guidance.
Appendix E: Radon
Appendix Sis a brief discussion of radon.
To learn more about how to check for
radon in your building, refer to this
appendix. Appendix G will direct you to
other sources of information.
About This Document 3
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Appendix F; Glossary and Acronyms
Appendix F explains scientific and
engineering terminology that may be
unfamiliar to some readers.
Appendix G; Resources
Appendix G is intended for readers who
want to pursue more detailed information
about indoor air quality. It includes the
names, addresses, and telephone numbers
of Federal, State, and private sector organi-
zations with interests related to IAQ, as
well as a list of selected publications,
Contaminant emission and movement in
buildings is an emerging field of study.
Building owners, facility managers, and
engineers are urged to keep abreast of new
information through professional journals
and seminars in addition to relying on the
guidance presented in this document.
Tab V; Indoor Air Quality Forms
Tab V contains a full set of the forms
described in Tabs II and III. Building
managers are encouraged to reproduce and
use these blank forms. You may want to
modify elements of these forms to reflect
conditions in your particular building.
WARNING
Please note the following as you prepare to
use this manual:
Modification of building functions to
remedy air quality complaints may create
other problems, A thorough understand-
ing of all of the factors that interact to
create indoor quality problems can help
to avoid this undesirable outcome,
The guidance in this document is not
intended as a substitute for appropriate
emergency action in the event of a
hazardous situation that may be
imminently threatening to life or safety.
The implementation of mitigation
recommendations reached as a result of
an indoor air quality evaluation should
always be done in accordance with local
laws and good practice. Changes to the
overall design and operation of the
building may necessitate the involve-
ment of a registered professional engi-
neer or other registered or certified
professionals.
In the event that medical records are
utilized in the course of evaluating an
IAQ problem, appropriate legal confi-
dentiality must be maintained.
4 Section 1
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Factors Affecting Indoor Air Quality
I he indoor environment in any building is
a result of the interaction between the site,
climate, building system (original design
and later modifications in the structure and
mechanical systems), construction tech-,
niques, contaminant sources (building
materials and furnishings, moisture,
processes and activities within the building,
and outdoor sources), and building occu-
pants.
The following four elements are involved
in the development of indoor air quality
problems:
Source: there is a source of contamination
or discomfort indoors, outdoors, or within
the mechanical systems of the building.
HVAC: the HVAC system is not able to
control existing air contaminants and ensure
thermal comfort (temperature and humidity
conditions that are comfortable for most
occupants).
Pathways: one or more pollutant pathways
connect the pollutant source to the occu-
pants and a driving force exists to move
pollutants along the pathway(s).
Occupants: building occupants are present.
It is important to understand the role that
each of these factors may play in order to
prevent, investigate, and resolve indoor air
quality problems.
SOURCES OF INDOOR AIR
CONTAMINANTS
Indoor air contaminants can originate
within the building or be drawn in from
outdoors. If contaminant sources are not
controlled, IAQ problems can arise, even if
the HVAC system is properly designed and
well-maintained. It may be helpful to think
of air pollutant sources as fitting into one of
the categories that follow. The examples
given for each category are not intended to
be a complete list.
Sources Outside Building
Contaminated outdoor air
pollen, dust, fungal spores
industrial pollutants
general vehicle exhaust
Emissions from nearby sources
m exhaust from vehicles on nearby roads
or in parking lots or garages
loading docks
odors from dumpsters
re-entrained (drawn back into the
building) exhaust from the building
itself or from neighboring buildings
unsanitary debris near the outdoor air
intake
Soil gas
radon
leakage from underground fuel tanks
contaminants from previous uses of the
site (e.g., landfills)
pesticides
Moisture or standing water promoting
excess microbial growth
rooftops after rainfall
crawlspace
Equipment
HVAC system
m dust or dirt in ductwork or other
components
microbiological growth in drip pans,
humidifiers, ductwork, coils
improper use of biocides, sealants, and/
or cleaning compounds
improper venting of combustion
products
refrigerant leakage
Four elements
sources, the HVAC
system, pollutant
pathways, and
occupants are
Involved in the
development of IAQ
problems.
Factors Affecting Indoor Air Quality S
-------
Given our present
knowledge, it is
difficult to relate
complaints of
specific health
effects to exposures
to specific pollutant
concantratlons,
especially since the
significant exposures
may bo to low levels
of pollutant mixtures.
Non-HVAC equipment
emissions from office equipment (vola-
tile organic compounds, ozone)
supplies (solvents, toners, ammonia)
emissions from shops, labs, cleaning
processes
elevator motors and other mechanical
systems
Human Activities
Personal activities
smoking
cooking
Body odor
cosmetic odors
Housekeeping activities
m cleaning materials and procedures
emissions from stored supplies or trash
use of deodorizers and fragrances
airborne dust or dirt (e.g., circulated by
sweeping and vacuuming)
Maintenance activities
microorganisms in mist from improp-
erly maintained cooling towers
airborne dust or dirt
volatile organic compounds from use of
paint, caulk, adhesives, and other
products
pesticides from pest control activities
emissions from stored supplies
Building Components and Furnishings
Locations that produce or collect dust or
fibers
textured surfaces such as carpeting,
curtains, and other textiles
open shelving
old or deteriorated furnishings
materials containing damaged asbestos
Unsanitary conditions and water damage
microbiological growth on or in soiled
or water-damaged furnishings
microbiological growth in areas of
surface condensation
standing water from clogged or poorly
designed drains
dry traps that allow the passage of
sewer gas
Chemicals released from building
components or furnishings
volatile organic compounds or
inorganic compounds
Other Sources
Accidental events
m spills of water or other liquids
microbiological growth due to flooding
or to leaks from roofs, piping
fire damage (soot, PCBs from electrical
equipment, odors)
Special use areas and mixed use buildings
m smoking lounges
laboratories
print shops, art rooms
exercise rooms
beauty salons
food preparation areas
Redecorating/remodeling/repair activities
emissions from new furnishings
dust and fibers from demolition
odors and volatile organic and inorganic
compounds from paint, caulk, adhesives
microbiologicals released from demoli-
tion or remodeling activities
Indoor air often contains a variety of
contaminants at concentrations that are far
below any standards or guidelines for
occupational exposure. Given our present
knowledge, it is difficult to relate com-
plaints of specific health effects to expo-
sures to specific pollutant concentrations,
especially since the significant exposures
may be to low levels of pollutant mixtures.
HVAC SYSTEM DESIGN AND
OPERATION
The HVAC system includes all heating,
cooling, and ventilation equipment serving
a building: furnaces or boilers, chillers,
cooling towers, air handling units, exhaust
fans, ductwork, filters, steam (or heating
water) piping. Most of the HVAC discus-
sion in this document applies both to central
HVAC systems and to individual compo-
nents used as stand-alone units.
6 Section 2
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A properly designed and functioning
HVAC system:
provides thermal comfort
distributes adequate amounts of outdoor
air to meet ventilation needs of all
building occupants
isolates and removes odors and con-
taminants through pressure control,
filtration, and exhaust fans
Thermal Comfort
A number of variables interact to deter-
mine whether people are comfortable with
the temperature of the indoor air. The
activity level, age, and physiology of each
person affect the thermal comfort require-
ments of that individual. The American
Society of Heating, Refrigerating, and Air-
Conditioning Engineers (ASHRAE)
Standard 55-1981 describes the tempera-
ture and humidity ranges that are comfort-
able for most people engaged in largely
sedentary activities. That information is
summarized on page 57. The ASHRAE
standard assumes "normal" indoor
clothing. Added layers of clothing reduce
the rate of heat loss.
Uniformity of temperature is important
to comfort When the heating and cooling
needs of rooms within a single zone
change at different rates, rooms that are
served by a single thermostat may be at
different temperatures. Temperature
stratification is a common problem caused
by convection, the tendency of light, warm
air to rise and heavier, cooler air to sink. If
air is not properly mixed by the ventilation
system, the temperature near the ceiling
can be several degrees warmer than at
floor level. Even if air is properly mixed,
uninsulated floors over unheated spaces
can create discomfort in some climate
zones. Large fluctuations of indoor
temperature can also occur when controls
have a wide "dead band" (a temperature
range within which neither heating nor
cooling takes place).
Radiant heat transfer may cause people
located near very hot or very cold surfaces
to be uncomfortable even though the
thermostat setting and the measured air
temperature are within the comfort range.
Buildings with large window areas
sometimes have acute problems of discom-
fort due to radiant heat gains and losses,
with the locations of complaints shifting
during the day as the sun angle changes.
Large vertical surfaces can also produce a
significant flow of naturally-convecting air,
producing complaints of draftiness.
Adding insulation to walls helps to
moderate the temperature of interior wall
surfaces. Closing curtains reduces heating
from direct sunlight and isolates building
occupants from exposure to window
surfaces (which, lacking insulation, are
likely to be much hotter or colder than the
walls).
Humidity is a factor hi thermal comfort.
Raising relative humidity reduces the
ability to lose heat through perspiration and
evaporation, so that the effect is similar to
raising the temperature. Humidity ex-
tremes can also create other IAQ problems.
Excessively high or low relative humidities
can produce discomfort, while high relative
humidities can promote the growth of mold
and mildew. (See Appendix C.)
Ventilation to Meet Occupant
Needs
Most air handling units distribute a blend
of outdoor air and recirculated indoor air.
HVAC designs may also include units that
introduce 100% outdoor air or that simply
transfer air within the building. Uncon-
trolled quantities of outdoor air enter
buildings by infiltration through windows,
doors, and gaps in the exterior construc-
tion. Thermal comfort and ventilation
needs are met by supplying "conditioned"
air (a blend of outdoor and recirculated air
that has been filtered, heated or cooled, and
sometimes humidified or dehumidified).
A number of
variables, including
personal activity
levels, uniformity of
temperature, radiant
heat gain or loss, and
humidity, interact to
determine whether
people are comfortable
with the temperature
of the indoor air.
Factors Affecting Indoor Air Quality 7
-------
Hie amount of
outdoor air
considered adequate
for proper ventilation
has varied
substantially over
time. The current
guideline issued by
ASHRAE is Standard
02-1989.
Large buEdings often have interior
("core") spaces in which constant cooling
is required to compensate for heat gener-
ated by occupants, equipment, and
lighting, while perimeter rooms may
require heating or cooling depending on
outdoor conditions.
Two of the most common HVAC
designs used in modern public and
commercial buildings are constant volume
and variable air volume systems. Con-
stant volume systems are designed to
provide a constant airflow and to vary the
air temperature to meet heating and
cooling needs. The percentage of outdoor
air may be held constant, but is often
controlled either manually or automatically
to vary with outdoor temperature and
humidity. Controls may include a mini-
mum setting that should allow the system
to meet ventilation guidelines for outdoor
air quantities under design conditions.
Variable air volume (VAV) systems
condition supply air to a constant tempera-.
ture and ensure thermal comfort by varying
the airflow to occupied spaces. Most early
VAV systems did not allow control of the
outdoor air quantity, so that a decreasing
amount of outdoor air was provided as the
flow of supply air was reduced. Some
more recent designs ensure a minimum
supply of outdoor air with static pressure
devices in the outdoor air stream. Addi-
tional energy-conserving features such as
economizer control or heat recovery are
also found in some buildings.
Good quality design, installation, and
testing and balancing are critically impor-
tant to the proper operation of all types
of HVAC systems, especially VAV
systems, as are regular inspections and
maintenance. (See Appendix B for further
discussion of HVAC system types.)
The amount of outdoor ah* considered
adequate for proper ventilation has varied
substantially over tune. The current
guideline issued by ASHRAE is ASHRAE
Standard 62-1989. The building code mat
was in force when your building HVAC
system was designed may well have
established a lower amount of ventilation
(in cubic feet of outdoor air per minute per
person) than is currently recommended.
(A table of outdoor air quantities recom-
mended by ASHRAE is reproduced on
page 136 in Appendix B, Note that other
important aspects of the standard are not
included in this table.)
Control of Odors and
Contaminants
One technique for controlling odors and
contaminants is to dilute them with
outdoor air. Dilution can work only if
there is a consistent and appropriate flow
of supply air that mixes effectively with
room air. The term "ventilation effi-
ciency" is used to describe the ability of
the ventilation system to distribute supply
air and remove internally generated
pollutants. Researchers are currently
studying ways to measure ventilation
efficiency and interpret the results of those
measurements.
Another technique for isolating odors
and contaminants is to design and operate
the HVAC system so that pressure
relationships between rooms are con-
trolled. This control is accomplished by
adjusting the ah quantities that are
supplied to and removed from each room.
If more air is supplied to a room than is
exhausted, the excess air leaks out of the
space and the room is said to be under
positive pressure. If less air is supplied
than is exhausted, air is pulled into the
space and the room is said to be under
negative pressure.
Control of pressure relationships is
critically important in mixed use buildings
or buildings with special use areas.
Lobbies and buildings in general are often
designed to operate under positive pressure
to prevent or minimize the infiltration of
unconditioned air, with its potential to
cause drafts and introduce dust, dirt, and
thermal discomfort. Without proper
operation and maintenance, these pressure
8 Section 2
-------
differences are not likely to remain as
originally designed.
A third technique is to use local exhaust
systems (sometimes known as dedicated
exhaust ventilation systems) to isolate and
remove contaminants by maintaining
negative pressure in the area around the
contaminant source. Local exhaust can be
linked to the operation of a particular piece
of equipment (such as a kitchen range) or
used to treat an entire room (such as a
smoking lounge or custodial closet). Air
should be exhausted to the outdoors, not
recireulated, from locations which produce
significant odors and high concentrations
of contaminants (such as copy rooms,
bathrooms, kitchens, and beauty salons).
Spaces where local exhaust is used must
be provided with make-up air and the local
exhaust must function in coordination with
the rest of the ventilation system. Under
some circumstances, it may be acceptable
to transfer conditioned air from relatively
clean parts of a building to comparatively
dirty areas and use it as make-up air for a
local exhaust system. Such a transfer can
achieve significant energy savings.
Air cleaning and filtration devices
designed to control contaminants are found
as components of HVAC systems (for
example, filter boxes in ductwork) and can
also be installed as independent units. The
effectiveness of air cleaning depends upon
proper equipment selection, installation,
operation, and maintenance. Caution
should be used in evaluating the many new
technological developments in the field of
air cleaning and filtration.
POLLUTANT PATHWAYS AND
DRIVING FORCES
Airflow patterns in buildings result from
the combined action of mechanical
ventilation systems, human activity, and
natural forces. Pressure differentials
created by these forces move airborne
contaminants from areas of relatively
higher pressure to areas of relatively lower
pressure through any available openings.
The HVAC system is generally the
predominant pathway and driving force for
air movement in buildings. However, all
of a building's components (walls, ceilings,
floors, penetrations, HVAC equipment, and
occupants) interact to affect the distribution
of contaminants.
tl
For example, as air moves from supply
registers or diffusers to return air grilles, it
is diverted or obstructed by partitions,
walls, and furnishings, and redirected by
openings that provide pathways for air
movement. On a localized basis, the
movement of people has a major impact on
the movement of pollutants. Some of the
pathways change as doors and windows
open and close. It is useful to think of the
entire building the rooms and the
connections (e.g., chases, corridors,
stairways, elevator shafts) between them
as part of the air distribution system.
Natural forces exert an important
influence on air movement between zones
and between the building's interior and
exterior. Both the stack effect and wind
can overpower a building's mechanical
system and disrupt air circulation and
ventilation, especially if the building
envelope is leaky.
Stack effect is the pressure driven flow
produced by convection (the tendency of
Chases, crawlspaces, and
other hidden spaces can be
both sources and pathways
for pollutants.
Factors Affecting Indoor Air Quality 9
-------
The basic principle of
air movement from
areas of relatively
higher pressure to
areas of relatively
lower pressure can
produce many
patterns of
contaminant
distribution.
warm air to rise). The stack effect exists
whenever there is an indoor-outdoor
temperature difference and becomes
stronger as the temperature difference
increases. As heated air escapes from
upper levels of the building, indoor air
moves from lower to upper floors, and
replacement outdoor air is drawn into
openings at the lower levels of buildings.
Stack effect airflow can transport contami-
nants between floors by way of stairwells,
elevator shafts, utility chases, or other
openings.
Wind effects are transient, creating local
areas of high pressure (on the windward
side) and low pressure (on the leeward
side) of buildings. Depending on the
leakage openings in the building exterior,
wind can affect the pressure relationships
within and between rooms.
The basic principle of air movement from
areas of relatively higher pressure to areas
of relatively lower pressure can produce
many patterns of contaminant distribution,
including:
local circulation in the room containing
the pollutant source
air movement into adjacent spaces that
are under lower pressure (Note: Even if
two rooms are both under positive
pressure compared to the outdoors, one
room is usually at a lower pressure than
the other.)
recirculation of air within the zone
containing the pollutant source or in
adjacent zones where return systems
overlap
movement from lower to upper levels of
the building
air movement into the building through
either infiltration of outdoor air or
reentry of exhaust air
Air moves from areas of higher pressure
to areas of lower pressure through any
available openings. A small crack or hole
can admit significant amounts of air if the
pressure differentials are high enough
(which may be very difficult to assess).
Even when the building as a whole is
maintained under positive pressure, there is
always some location (for example, the
outdoor air intake) that is under negative
pressure relative to the outdoors. Entry of
contaminants may be intermittent, occur-
ring only when the wind blows from the
direction of the pollutant source. The
interaction between pollutant pathways and
intermittent or variable driving forces can
lead to a single source causing IAQ
complaints in areas of the building that are
distant from each other and from the
source.
BUILDING OCCUPANTS
The term "building occupants" is generally
used in this document to describe people
who spend extended time periods (e.g., a
full workday) in the building. Clients and
visitors are also occupants; they may have
different tolerances and expectations from
those who spend their entire workdays in
the building, and are likely to be more
sensitive to odors.
Groups that may be particularly suscep-
tible to effects of indoor air contaminants
include, but are not limited to.
allergic or asthmatic individuals
people with respiratory disease
people whose immune systems are
suppressed due to chemotherapy,
radiation therapy, disease, or other
causes
contact lens wearers
Some other groups are particularly
vulnerable to exposures of certain
pollutants or pollutant mixtures. For
example, people with heart disease may be
more affected by exposure at lower levels
of carbon monoxide than healthy
individuals. Children exposed to environ-
mental tobacco smoke have been shown to
be at higher risk of respiratory illnesses
and those exposed to nitrogen dioxide have
been shown to be at higher risk from
respiratory infections.
10 Section 2
-------
Because of varying sensitivity among -
people, one individual may react to a
particular IAQ problem while surrounding
occupants have no ill effects. (Symptoms
are limited to a single person can also
occur when only one work station receives
the bulk of the pollutant dose.) In other
cases, complaints may be widespread,
A single indoor air pollutant or problem
can. trigger different reactions in different
people. Some may not be affected at all.
Information about the types of symptoms
can sometimes lead directly to solutions.
However, symptom information is more
likely to be useful, for identifying the timing
and conditions under which problems '
occur.
Types of Symptoms and
Complaints
The effects of IAQ problems ire often non-
specific symptoms rather than clearly ;
defined illnesses. Symptoms commonly
attributed to IAQ problems include:
headache
fatigue
* shortness of breath
ซ sinus congestion
* cough
sneezing
eye, nose, and throat irritation
skin irritation
dizziness
nausea
All of these symptoms, however, may also
be caused by other factors, and are not
necessarily due to air quality deficiencies.
"Health" and "comfort" are used to
describe a spectrum of physical sensations.
For example, when the air in a room is
slightly too warm for a person's activity
level, that person may experience mild
discomfort. If the temperature continues to
rise, discomfort increases and symptoms
such as fatigue, stuffiness, and headaches
can appear.
Some complaints by building occupants
are clearly related to the discomfort end of
the spectrum. One of the most common
IAQ complaints-is that "there's a funny
smell in here." Odors are often associated
with a perception of poor air quality,
whether or not they cause symptoms.
Environmental stressors such as improper
lighting, noise, vibration, overcrowding,
ergonomic stressors, and job-related
psychosocial problems .(such as job stress)
can produce symptoms that are similar to
those associated with poor air quality.
The term sick building syndrome (SBS)
is sometimes used to describe cases in
which building occupants experience acute
health and comfort effects that are appar-
ently linked to the time they spend in the
building, but in which no specific illness or
cause can be identified. The complaints
may be localized in a particular room or
zone or may be widespread throughout the
building. Many different symptoms have
been associated with SBS, including
respiratory complaints, irritation, and
fatigue. Analysis of air samples often fails
to detect high concentrations of specific
contaminants. The problem may be caused
by any or all of the following:
the combined effects of multiple
pollutants at low concentrations
other environmental stressors
(e.g., overheating, poor lighting, noise)
ergonomic stressors
job-related psychosocial stressors
(e.g., overcrowding, labor-management
problems)
unknown factors
Building-related illness (BET) is a term
referring to illness brought on by exposure
to the building air, where symptoms of
diagnosable illness are identified (e.g.,
certain allergies or infections) and can be
directly attributed to environmental agents
in the air. Legionnaire's disease and
hypersensitivity pneumonitis are examples
of BRI that can have serious, even life-
threatening consequences.
Environmental
stressors such as
improper lighting,
noise, vibration, '
overcrowding,
ergonomic stressors,
and Job-related *'-
psychosocial
problems (such as job
stress) can produce
symptoms that are
similar to those
associated with poor
air quality.
Factors Affecting Indoor Air Quality 11
-------
A small percentage of the population
may be sensitive to a number of chemicals
in indoor air, each of which may occur at
very low concentrations. The existence of
this condition, which is known as multiple
chemical sensitivity (MCS), is a matter of
considerable controversy. MCS is not
currently recognized by the major medical
organizations, but medical opinion is
divided, and further research is needed.
The applicability of access for the disabled
and worker's compensation regulations to
people who believe they are chemically
sensitive may become concerns for facility
managers.
Sometimes several building occupants
experience rare or serious health problems
(e.g., cancer, miscarriages, Lou Gehrig's
disease) over a relatively short time period.
These clusters of health problems are
occasionally blamed on indoor air quality,
and can produce tremendous anxiety
among building occupants, State or local
Health Departments can provide advice
and assistance if clusters are suspected.
They may be able to help answer key
questions such as whether the apparent
cluster is actually unusual and whether the
underlying cause could be related to IAQ.
12 Section 2
-------
Effective Communication
I Ms section discusses establishing and
maintaining a communication system that
can help prevent indoor air quality
problems and resolve problems coopera-
tively if they do arise. If you. are currently
responding to an indoor air quality
complaint, you may want to skip ahead to
the discussion of Communicating to
Resolve IAQ Problems on page 15.
COMMUNICATING TO PREVENT
IAQ PROBLEMS
Effective communication can encourage
building occupants to improve their work
environment through positive contribu-
tions. The following objectives should be
kept in mind while reviewing and revising
your current approach to communicating
with occupants:
provide accurate information about
factors that affect indoor air quality
clarify the responsibilities of each party
(e.g., building management, staff, ten-
ants, contractors)
establish an effective system for logging
and responding to complaints should
they occur
Provide Accurate Information
Many indoor air quality problems can be
prevented if staff and building occupants
understand how their activities affect IAQ.
You may already have a health and safety
committee functioning to promote good
working conditions. If so, it is easy to add
indoor air quality to their list of concerns.
If you do not have a health and safety
committee, consider establishing one or
setting up a joint management-tenant IAQ
task force. Whatever its official designa-
tion, such a group can help to disseminate
information about indoor air quality, bring
potential problems to the attention of
building staff and management, and foster
a sense of shared responsibility for
maintaining a safe and comfortable indoor
environment.
The group will be most successful if it
represents the diverse interests in the
building, including:
building owner
building manager
facility personnel
health and safety officials
tenants and/or other occupants who are
not facility staff
union representatives (or other worker
representatives)
Clarify Responsibilities
It is important to define the responsibilities
of building management, staff, and
occupants in relation to indoor air quality.
These responsibilities can be formalized by
incorporating them into documents such as
employee manuals or lease agreements.
The occupant in this room
covered the supply air vents
with papers. Whether this
was done to reduce uncom-
fortable drafts or to provide
more shelf space, the result
can disrupt the air flow, not
only through this room but
elsewhere in the building.
By tampering with the air
handling system, occupants
can unintentionally cause
complaints in other areas.
Effective Communication 13
-------
Use of space: Educate occupants about the
permitted uses and maximum occupancy of
different areas within the building and
make sure that appropriate ventilation is
provided for the activities that are permit-
ted. Indoor air quality complaints often
arise in mixed-use buildings. For example,
kitchen staff expect food odors as part of
their work, but nearby office workers may
find cooking odors distracting and unpleas-
ant. Problems can also arise when old
tenants leave and new arrivals introduce
new uses of the building.
Occupancy Rate: Inform occupants about
the importance of keeping the building
management informed about significant
changes in the number of people regularly
using particular areas of the building. The
ventilation systems in buildings are
designed and operated to supply air to
AND OCCUPANT COOPERATION
;;|! ..... , ...... ON INDOOR AIR QUALITY
The State of Wisconsin's "Quality Building Management" system
has helped to unite the diverse interests involved in operating
and using State office buildings. Tenants and facility personnel
Volunteered to serve on teams, working cooperatively to improve
the quality of the indoor environment.
, gach tearn was assigned a specific area for which it drafted
::i:::':^ '^jdeaj E|ujldmg Standards." Air quality was'one such area;
others Included elevators, rest rooms, and work spaces, the IAQ
,| jij|| | iiiiii||i|ji||jซ- || pi'1 in,' iiiiiii|||||i
-------
Complaints should be handled
promptly, with every incident given
serious attention. It is advisable to
establish a recordkeeping system that
cross-references documentation on
complaints with records of equipment
operation and maintenance. The
recordkeeping system can help to resolve
complaints by collecting information in a
form that highlights patterns of problems
(for example, complaints that occur at a
regular time of day or in the same area of
the building). The IAQ Complaint Form
and Incident Log shown here and on the
following page (and also reproduced in
Tab V) can be used to track complaints
related to the indoor environment.
COMMUNICATING TO RESOLVE
IAQ PROBLEMS
In many cases, building managers may be
alerted to potential indoor air quality
problems by complaints from occupants.
The complaints can be vague, to the effect
that one or more people feel "sick" or
"uncomfortable" or that someone has
noticed an unusual odor. They may be
specific, blaming a particular material as
the cause of discomfort or health problems.
People are usually reacting to a real
problem, so their complaints should be
taken seriously. However, they may
attribute their symptoms to the wrong
cause, so their theories about the problem
should be heard respectfully but weighed
cautiously.
Indoor air quality problems can
sometimes be identified and resolved
quickly. On other occasions, complaints
originate from the interaction of several
variables, and detailed investigation may
be necessary in order to resolve the
problem.
The Importance of Responding
to IAQ Complaints
Listening and responding to building
occupants is critical to achieving a
ample Form
Indoor Mr Quality Complaint Form
"*4 ซ, ซ ,*.
jJagSviM-S
fhisjwm^should be used if your complaint may b0 related to
mdo'or air quality. Indoor air quality problems include concerns
ith fernperature control, ventilation, and air pollutants. Your
""Nervations can help to resolve the problem as quickly as possible.
se use the space below to describe the nature of the complaint
f a'rVd any potential causes.
riay need^to contact you to discuss your complaint. What is the
IFbesttimeto reach you?
fwj&-
rSo that we can respond promptly, please return this form to:
HilAQ Manager or Contact Person
BKSSj&'ttrr & * I.M _>-
tt& ' * . ' 1 " . .
successful resolution of indoor air quality
complaints. IAQ complaints may be
grounded in poor indoor air quality,
thermal conditions, noise, glare, or even
job stresses. However, it is in the building
.manager's best interest to respond to all
complaints about the indoor environment
promptly and seriously and to establish
credibility through open communication
with building occupants. The biggest
mistake that building managers can make
in the face of an IAQ complaint is to
underestimate the problems that can result
if building occupants believe that no action
is being taken or that important informa-
tion is being withheld. Without open
communication, any IAQ problem can
become complicated by anxiety, frustra-
tion, and distrust, delaying its resolution.
Paying attention to communication, as
well as problem-solving, helps to ensure
Effective Communication 15
-------
!!!1:^ ..',:.;(
i,i'^^^^ !','.- ..." ;,.;
ttfii USeMliil ^.j,1 J
~:
Investigation Record
(check the forms that were used)
Probtom
Location
Outcome /
Comments
Log Entry By
(initials)
COMPLETE
Sm~'""
PAQE183
The massages to
convey ara that
management believes
ft Is important to
provide a healthy and
safe building, that
good indoor air
quality is an essential
component of a
healthful indoor
environment, and that
complaints about
indoor air quality are
taken seriously.
the support and cooperation of building
occupants as the complaint is investigated
and resolved. The messages to convey are
that management believes it is important to
provide a healthy and safe building, that
good indoor air quality is an essential
component of a healthful indoor environ-
ment, and that complaints about indoor air
quality are taken seriously.
Communications, whether they occur in
conversations or in writing, should include
the following information:
what types of complaints management
has received
management's policy in regard to
providing a healthy and safe environ-
ment and responding to occupant
complaints
what management has done to date (e.g.,
collecting data, responding to the
problem)
what management plans to do in order to
further investigate and correct the
problem (including the fact that outside
consultants have been called in, if they
have been)
the names and telephone numbers of
appropriate facility management,
medical, or health and safety staff to
whom the occupants should turn if they
have additional complaints or questions,
or if they have information that may help
in resolving the complaints
Maintaining the Lines of
Communication
Make certain that occupants know how to
contact the responsible personnel who can
receive and respond to IAQ complaints.
Tenants may also have an internal system
for channeling complaints, for example
through a health and safety representative,
supervisor, or company doctor.
Indoor air quality complaints that can
be resolved quickly and that involve small
numbers of people (e.g., annoying but
harmless odors from an easily-identified
source) can be handled matter-of-factly
like other minor problems without risking
confusion and bad feeling among other
building occupants. Communication
becomes a more critical issue when there
are delays hi identifying and resolving the
problem and when serious health concerns
are involved.
16 Sections
-------
If the problem seems to be widespread
or potentially serious, it is advisable to
work with your health and safety commit-
tee. If you do not have a health and safety
committee, consider forming one, or
establishing a joint management-tenant
IAQ task force. (See the discussion on
page 13.)
Productive relations will be enhanced if
occupants are given basic information
during the process of investigation and
mitigation. Potential critics can become
allies if they are invited to be part of the
problem-solving process and become
better educated about IAQ and building
operations. Building managers may be
understandably reluctant to share test
results or consultants' reports with their
tenants or employees, but secrecy in such
matters can backfire if information leaks
out at a later time.
Building management staff can be
encouraged to talk directly with occupants
both at the time a complaint occurs and
later during a diagnostic investigation.
Their observations about patterns of
symptoms or building conditions may
provide helpful information.
Confidentiality of records can be
important to occupants, especially if they
are concerned that IAQ complaints will
lead to negative reactions from their
employers. There may be legal penalties
for violating confidentiality of medical
records. By reassuring occupants that
privacy will be respected, investigators are
more likely to obtain honest and complete
information.
It is advisable to explain the nature of
investigative activities, so that rumors and
suspicions can be countered with factual
information. Notices or memoranda can
be delivered directly to selected occupants
or posted in general use areas. Newsletter
articles or other established communica-
tion channels can also be used to keep
building occupants up-to-date.
Problems can arise from saying either
too little or too much. Premature release
of information when data-gathering is still
incomplete can produce confusion,
frustration, and mistrust at a later date.
Similar problems can result from incorrect
representation of risk assuming the
worst case (or the best). However, if
progress reports are not given, people may
think nothing (or something terrible) is
happening. It is good practice to clear
each piece of information with the facility
manager, building owner, or legal counsel.
Management should attempt to be factual
and to the point when presenting informa-
tion such as:
the definition of the complaint area
based upon the location and distribution
of complaints (this may be revised as the
investigation progresses)
the progress of the investigation,
including the types of information that
are being gathered and ways that
occupants can help
factors that have been evaluated and
found not to be causing or contributing
to the problem
how long the investigation might take
attempts that are being made to improve
indoor air quality
work that remains to be done and the
schedule for its completion
Vague discomfort, intermittent symp-
toms, and complex interactions of job
stress with environmental factors, which
make IAQ problems difficult to investi-
gate, can also obscure the effects of
mitigation efforts. Even after the proper
mitigation strategy is in place, it may take
days or weeks for contaminants to dissi-
pate and symptoms to disappear. If
building occupants are informed that their
symptoms may persist for some time after
mitigation, the inability to bring instant
relief is less likely to be seen as a failure.
If the problem seems
to be widespread or
potentially serious, it
is advisable to work
with your health and
safety committee. If
you do not have a
health and safety
committee, consider
forming one, or
establishing a joint
management-tenant
IAQ task force.
Effective Communication 17
-------
Page Intentionally Blank
-------
Developing an IAQ Profile
1Q profile is a description of the
features of the building structure, function,
and occupancy that impact indoor air
quality. When you have completed the
IAQ profile, you should have an under-
standing of the current status of air quality
in the building and baseline information on
the factors that have a potential for causing
problems in the future.
The IAQ profile can help building
management to identify potential problem
areas and prioritize budgets for mainte-
nance and future modifications. Combined
with information on lighting, security, and
other important systems, it can become an
owner's manual that is specific to your
building and that will serve as a reference
in a variety of situations.
The key questions to answer while
developing the IAQ profile are:
How was this building originally
intended to function? Consider the
building components and furnishings,
mechanical equipment (HVAC and non-
HVAC), and the occupant population
and associated activities.
Is the building functioning as designed?
Find out whether it was commissioned.
Compare the information from the
commissioning to its current condition.
What changes in building layout and use
have occurred since the original design
and construction? Find out if the HVAC
system has been reset and retested to
reflect current usage.
What changes may be needed to prevent
IAQ problems from developing in the
future? Consider potential changes in
future uses of the building.
After reading this manual to develop a
feel for the issues involved in maintaining
good indoor air quality in a building, the
development of an IAQ profile should
become a priority. The process of
developing an IAQ profile should require
only a modest effort, from a few days to a
few weeks of staff time, depending on the
complexity of your building and the
amount of detailed information collected.
The work can be done in pieces over a
longer period, if necessary, to fit into a
building manager's busy schedule.
Over time, it is desirable to make some
actual measurements of airflow, tempera-
ture, relative humidity, carbon dioxide
(CO2), and/or pressure differentials (e.g., in
each of the air handling zones or other sub-
areas of the building). These measure-
ments provide far better information on
current conditions than can be obtained
from the plans and specifications, even if
" as-built records are available.
In addition, few buildings have been
adequately commissioned, so the system
may never have delivered the airflows
shown on the design drawings. In the
event of litigation around future IAQ
complaints, the value of the IAQ profile as
a resource document will be enhanced by
real-world measurements. (Refer to
Appendix G and the ASHRAE standard on
commissioning. The EPA document on
designing for good indoor air quality,
which is due to be published in 1992, will
contain a more complete discussion of the
process of commissioning buildings.)
Developing an IAQ Profile 19
-------
FIGURE 4-1: Developing an IAQ Profile
START
IMBHMi
I
1. Collect and
Review Existing
Records
Review design,
construction, and
operating documents
Check HVAC mainte-
nance records against
equipment lists
Review complaint
record
2. Conduct a
Walkthrough
Inspection of the
Building
Talk with staff and
other occupants
Look for IAQ problem
Indicators
3. Collect Detailed
Information
HVAC system
condition and
operation
Pollutant pathways
Pollutant sources
Occupants
Go to Section 6
PRODUCTS
Description of HVAC system
design and operation; set of
operating instructions, manuals
Set of maintenance and calibration
records
Inventory of locations where
occupancy, equipment, or building
have changed
Inventory of complaint locations
List of responsible staff and/or
contractors; evidence of training;
job descriptions
Identification of areas where
positive or negative pressures
should be maintained (sketch
plan)
Record of locations that need
monitoring or correction
Inventory of HVAC system
components needing repair,
adjustment or replacement
Record of control settings and
operating schedules
Completed plan showing airflow
directions or pressure differen-
tials in significant areas
Inventory of significant
pollutant sources and their
locations
Set of Material Safety Data
Sheets for supplies and
hazardous substances that are
stored or used in the building
Zone/Room Record
Yes
Did
you find
any IAQ
problems
Develop an IAQ management plan (see Section 5)
SKILLS REQUIRED TO CREATE
AN IAQ PROFILE
Many of the resources necessary for the
IAQ profile should already be on hand
within your organization. Additional
information can be collected by the staff
person or persons who have the following
skills:
basic understanding of HVAC system
operating principles
ability to read architectural and mechani-
cal plans and understand manufacturer's
catalog data on equipment
ability to identify items of office
equipment
ability to work cooperatively with
building occupants and gather informa-
tion about space usage
ability to collect information about
HVAC system operation, equipment
condition, and maintenance schedules
authority to collect information from
subcontractors about work schedules
and materials used (particularly cleaning
and pest control activities)
ability to understand the practical
meaning of the information contained in
the Material Safety Data Sheets
(MSDSs)
If direct measurements are to be
included in the IAQ profile, the staff
should have the tools and training to make
the following measurements (see Appendix
A for guidance on air sampling):
air volumes at supply diffusers and
exhaust grilles
CO2 concentration
temperature
relative humidity
pressure differentials
assessment of thermal and ventilation
load requirements
Section 8 provides guidance on hiring
IAQ professionals if you prefer to use
outside expertise to develop your IAQ
profile.
20 Section 4
-------
STEPS IN AN 1AQ PROFILE
The information needed for an IAQ profile
is similar to that which is collected when
solving indoor air quality problems, but
includes the entire building rather than
focusing on areas that may have caused an
identified problem. The IAQ profile
should be an organized body of records
that can be referred to in planning for
renovations, negotiating leases and
contracts, or responding to future com-
plaints.
The process of gathering information
for the IAQ profile can be divided into
three major stages;
1. Collect aad review existing records.
2. Conduct a walkthrough inspection of
the building.
3. Collect detailed information on the
HVAC system, pollutant pathways,
pollutant sources, and buMing
occupancy.
The first two stages should be carried
out as quickly as possible, but me third
stage can be handled as time allows so that
it does not interfere with other staff
responsibilities.
1. Collect and Review Existing
Records
Review construction and operating
documents
Collect any available documents that
describe the construction and operation of
the building: architectural and mechanical
plans, specifications, submittals, sheet
metal drawings, commissioning reports,
adjusting and balancing reports, inspection
records, and operating manuals. Many
buildings may lack some or all of these
documents. If there are no commssioning
reports or balancing reports, actual venti-
lation quantities may be quite different
from those indicated on mechanical design
:;
PRODUCTS OF THE REVIEW OF EXISTING RECORDS
- -ปTซl,.1 -"ซ.*...
?i" v I' I description of the HVAC system design and operation
fiปj' .(ag., original plans and specifications with changes indi-
_ฃ';ซ. cated or new sketch plans and notes, commissioning reports,
""'"' festlng and balancing reports)
:**ฃป asef of operating instructions, and maintenance and calibra-
;\" tijin records for HVAC system components (e.g., fans,
?7-ปj ^'clampers, fiitersj chillers, boilers, and control systems)
j.-cjjfan Inventory of locations where architectural or engineering
t^/^niodlfieations have taken pTace
?** an inventory of locations in which current occupancy or
,-^VK HVAC system operation represents a change from the
\L. Original design
an inventory of locations^where complaints have been
-: -:~7 common in the past
drawings. If are no operating or
maintenance manuals for HVAC equip-
ment, it is difficult for staff to carry out an
adequate preventive maintenance program.
Study the original architectural and
mechanical design so that you understand
the building's layout and intended func-
tions. Identify and note locations in which
changes in equipment or room usage create
a potential for indoor air quality problems
and give them special attention during the
walkthrough inspection.
Items of interest and the questions they
suggest could include the following:
Commissioning reports
Was the building properly commissioned
when it was first constructed, including
testing and balancing of the HVAC
system?
Operating manuals
a Do staff members understand how the
HVAC equipment is intended to operate?
Remodeled areas
m Has the HVAC system layout been
changed to accommodate new walls,
rearranged partitions, or similar architec-
tural modifications?
Developing an IAQ Profile 21
-------
At trw en
-
AddiSon, removal, or replacement of
HVAC equipment
Where the original equipment has been
replaced, do the newer units have the
same capacity as the originals?
Has new equipment been properly
installed and tested? Where equipment
has been removed, is it no longer
needed?
Changes in room use
Is there a need for additional ventilation
(supply and/or exhaust) due to increased
occupant population or new activities
within any area of the building?
Have new items of equipment (non-
HVAC) been provided with local exhaust
where needed? Look for unusual types
or quantities of equipment such as copy
machines or computer ternainals.
Check HVAC maintenance records
against equipment lists
Collect your existing maintenance and
calibration records and check them against
the construction documents (e,g., equip-
ment lists and mechanical plans). See
whether all components appear to be
receiving regular attention. Equipment that
SEMMumqwHUim
thewaifijrough Inspection, you should have:
:&4^ .K*
A(X ^including contact information:
nป ; -^SRB'i*-'** ~i*Btt8^*f*-*\ ".,-ปซป, vmm*--.- ซi3,-,^ซซ'ปi*.ซiป,-:
* oiimas, telephone num bars, job descriptions
------ ' ..... ""ซ u..^3ฃ^.imซH*,.. "s-~ CซซI'>**SSฃ."i:-!"-:*.ซซ-~-*ป-->^-"-'-'" ซ-.<ซ--
ป notes on training and experience of building staff
1 >ป',. " fir-"""': . !. ..'A
||tes and procedures used in: , ._ ..,,,,.
iB^^rt*'**' X?W^."S*^^SE^ *?---; . -i-* WIPPJL . -i,,: _...=. .,*
y.sป.^aa^g3W~-""..rf9ny
I;-. J''iii'?**R*BSi'iป! '.:!!^
ซ. Sketch plan with notes showing*.
.:_ ^".aS-^^wf^'-^tf*^^-'1^-."'-.-- Y -' " .....~v......
;-,* pressure relationships between special use areas and
. . .' .^'Ai^r;^am-ซlปK|!.,!..**X j^pffgij^aiS '^!l!li'Trf*?J^>%lfa .y^iKKS^'f" -:Sg"="3W~4ซซ^-ป V- - "*-. - =..v.^^wปilซMiW^-^ซ'lป*vW'flf**WปHl(.*'fi
"^^yyrouriifflngrooms r ,..,.,.. ... ......,,..v.ป--.-^ . -.
>' # '^itlfil1i.,l{L1lflMgh general indicators of IAQ problems show.
thi'niedI for cjosf monitqringior corrective action
.OMsffl^S'rtS^^tefflW'ilSaiitfSaSE''iJI
has been Jnstaled in inaccessible or out-of-
the-way locations is frequently overlooked
during routine maintenance, TMsis
particularly true of items such as filter
boxes and small capacity exhaust fans.
Review records of complaints
ff there is an organized record of past
occupant complaints about the building
environment, review those complaints to
identify building areas that deserve
particular attention.
2. Conduct a Walkthrough
Inspection off the Building
The intent of the walkthrough inspection is
to acquire a good overview of occupant
activities and building functions and to
look for IAQ problem indicators. No
specific forms are suggested for this stage
of IAQ profile development. However,
the investigator should have a sketch plan
of the building, such as a small floor plan
showing fire exits, so that Ms or her notes
can be referenced to specific locations.
Detailed measurements of temperature,
humidity, airflow, or other parameters are
more appropriate to a later stage of profile
development. However, chemical smoke
can be used to observe airflow patterns and
pressure relationships between special use
areas or other identified pollutant sources
and surrounding rooms. Odors in inappro-
priate locations (e.g., kitchen odors in a
lobby) may indicate mat ventilation system
components require adjustment or repair.
(See Appendix A for further discussion of
the use of chemical smoke.)
The value of IAQ ventilation measure-
ment tools to your operation will grow as
you become more familiar with handling
indoor air quality concerns. For example,
if you do not own a direct-reading carbon
dioxide monitor, it is not necessary to
acquire one for the IAQ profile. Those
who already have access to this type of
instrument can take readings during the
walkthrough as a way to obtain baseline
22 Section 4
-------
information about normal operating
conditions or identify problem locations.
If you begin to suspect that underventila-
tion is a consistent problem, you may
decide that it would be helpful to obtain
more ventilation monitoring equipment,
(See Appendix A for further discussion of
carbon dioxide and other ventilation
measurements.)
Talk with staff and other occupants
A walkthrough inspection provides an
opportunity to introduce facility staff and
other building occupants to the topic of
indoor air quality and to understand current
staff (and contractor) responsibilities in
relation to housekeeping and maintenance
activities. Advance notice of the inspec-
tion will make it seem less intrusive and
may encourage staff and other occupants to
remember important information.
Discussion of routine activities in the
building will help to clarify elements that
should be included in the IAQ manage-
ment plan. Ask staff members about their
job responsibilities, training and experi-
ence. It will be helpful to meet with
responsible staff and contractors to
discuss:
Facility operation and maintenance
(e.g., HVAC, plumbing, electric, interior
maintenance)
HVAC operating schedule (e.g., occu-
pied/unoccupied cycles)
HVAC maintenance schedule (e.g., filter
changes, drain pan maintenance)
use and storage of chemicals
schedule of shipping and receiving,
handling of vehicles at loading dock
scheduling and other procedures for
isolating odors, dust, and emissions from
painting, roof repair, and other contami-
nant-producing activities
budgeting (e.g., including staff influence
on budget decisions)
Housekeeping
cleaning schedule
trash storage and schedule of refuse
removal
use and storage of chemicals
Pest control
schedule and location of pesticide
applications
use and storage of chemicals
pest control activities other than use of
pesticides
Look for IAQ problem indicators
The walkthrough inspection can be used to
identify areas with a high potential for IAQ
problems. The following are general
indicators of IAQ problems:
odors
dirty or unsanitary conditions (e.g.,
excessive dust)
visible fungal growth or moldy odors
(often associated with problem of too
much moisture)
Maintenance is more likely
to be performed on a
routine basis when there Is
good access to HVAC
equipment such as that
shown in this photo.
Developing an IAQ Profile 23
-------
Building occupants who are
uncomfortable may try to
Improve the situation by
themselves. The small fans
shown above indicate an air
circulation or thermal
discomfort problem. The
Irony of this situation is that
the fan motors add heat to
the sir.
m sanitary conditions in equipment such as
drain pans and cooling towers
poorly-maintained filters
signs of mold or moisture damage at
walls (e.g., below windows, at columns,
at exterior corners), ceilings, and floors
staining and discoloration (Note; Make
sure that stains are removed after leaks
are repaired so that there will be visible
evidence if the leak recurs.)
smoke damage (Note: If a fire has
occurred involving electrical equipment,
determine whether PCBs (polychlori-
nated biphenyls) may have been released
from the equipment.)
presence of hazardous substances
potential for soil gas entry (e.g., unsealed
openings to earth, wet earth smells)
unsanitary mechanical room, or trash or
stored chemicals in mechanical room
unusual noises from light fixtures or
mechanical equipment
In addition to these general indications,
some common problems deserve mention:
Inadequate maintenance: Look for leaks
of oil, water, or refrigerants around HVAC
equipment. Also be aware of signals such
as unreplaced burned-out light bulbs in fan
chambers and staff members who have
difficulty locating specific pieces of
equipment. Dry drain traps can also cause
indoor air quality problems. If traps are
not kept charged with liquid, they could be
allowing sewer gas to enter occupied
spaces.
Signs of occupant discomfort: Notice
uneven temperatures, persistent odors
(including tobacco smoke), drafts, sensa-
tions of stuffiness. You may find that
occupants are attempting to compensate
for an HVAC system that doesn't meet
their needs. Look for propped-open
corridor doors, blocked or taped-up
diffusers, popped-up ceiling tiles, people
using individual fans/ heaters or wearing
heavier (or lighter) clothing than normal.
Overcrowding: Future occupant density is
estimated when the ventilation system for a
building is designed. When the actual
number of occupants approaches or
exceeds this occupant design capacity,
managers may find that IAQ complaints
increase. At that point, the outdoor air
ventilation rate will have to be increased.
However, the ventilation and cooling
systems may not have sufficient capacity
to handle the increased loads from the
current use of the space.
Blocked airflow: Check for under-
ventilation caused by obstructed vents,
faulty dampers or other HVAC system
malfunctions, or from problems within the
occupied space. Furniture, papers, or other
materials can interfere with air movement
around thermostats or block airflow from
wall or floor-mounted registers. If office
cubicles are used, a small space (i.e., two
to four inches) between the bottom of the
partitions and the floor may improve air
circulation.
Ceiling plenums: Lift a ceiling tile and
examine the plenum for potential prob-
24 Section 4
-------
lems. Walls or full-height partitions that
extend to the floor above can obstruct or
divert air movement in ceiling plenums
unless transfer grilles have been provided.
If fire dampers have been installed to
allow air circulation through walls or
partitions, confirm that the dampers are.
open. Construction debris and damaged or
loose material in the plenum area may
become covered with dust and can release
particles and fibers.
Heat sources: Be aware of areas that
contain unusual types or quantities of
equipment such as copy machines or
computer terminals. Also look for
instances of over-illumination. High
concentrations of electrical fixtures and
equipment can overwhelm the ventilation
and cooling systems.
Special use areas: Confirm that the
HVAC system maintains appropriate
pressure relationships to isolate and
contain odors and contaminants in mixed-
use buildings and around special use areas.
Examples of special use areas include
attached parking garages, loading docks,
print shops, smoking lounges, janitorial
closets, storage areas, and kitchens.
Improperly located vents, exhausts and
air intakes: Check the outdoor air intakes
to see whether they are located near
contaminant sources (e.g., plumbing vents,
exhaust outlets, dumpsters, loading docks,
or other locations where vehicles idle).
Unsanitary mechanical rooms: See if the
space containing the HVAC system is
clean and dry. Examples of problems
include: cleaning or other maintenance
supplies stored in mechanical room; dust
and dirt buildup on floors and equipment;
moisture hi mechanical room because of
inadequate insulation, lack of conditioned
air, or failure to provide for air movement.
Unsanitary conditions in the mechanical
room are particularly a problem if
unducted return air is dumped into and
circulated through the mechanical room.
PRODUCTS OF COLLECTING DETAILED INFORMATION
'. ji an inventory of HVAC system components that need to be
S^.'ffepaired, adjusted, or replaced
~S m a current record of control settings and operating schedules
}-'-- a floor plan of the building showing airflow directions or
^-i--^- pressure differentials around areas intended to run positive or
'jjjgji. negative (e.g., special use areas)
Hjjl an inventory of pollutant sources and their locations
|fiji Material Safety Data Sheets for products used or stored within
i~i~ the building
^.IL a" record of usage for each zone or room, including the source of
e air and the presence of local exhaust (if any)
-VH v.'f^v " - >.!''-iw'':"*!
1' it^'*'''v/^-v f'ซf,||;'^^^ii^vv
'- ^s?^ vV'^l'^l:4::^l"^1p|k'ฅ
' ' ' i I *, f ซf 'S fr,
^f:|
S^:K -1
-, . ;
'" ' " .* I if f's ,';
- -
P^: ;i
Collect Detailed Information
The collection of detailed information for
the IAQ profile can be handled as time is
available. Areas that have been identified
as presenting potential IAQ problems
should be given the highest priority. You
may want to review Section 2 for back-
ground information on the factors that
contribute to indoor air quality.
Inspect HVAC system condition and
operation
Use your current maintenance records in
combination with one or both of the
HVAC Checklists to inspect HVAC
Occupants or staff
sometimes open ceiling
tiles into return plenums
when-attempting to
eliminate odors. Building
managers should be alert to
such signs of occupant
dissatisfaction in order to
remedy the original
problem and prevent
additional problems, such
as the short-circuiting of
supply air.
Developing an IAQ Profile 25
-------
Sample Form
HVAC Checklist Shock Form
Mechanical Room
M Clean and dry?
' (describe items in need of attention) ' - . : - ; : - ; ;
* Stored refuse or chemicals?
jr.
- . ..... ~-.~ ...... : ....... .- y ........ ,
.
Machanicnl Equipment , ,. ,, .
'4- *, - *' V!L v "1
,
Preventative maintenance^ (PM) plan in use? - :
^ - ฃ-, ; - Hr; -%< \ - ' ' ' '
ซ=. Control System type
'"'
_ * System operation - -
ซ="'. 1.-.J
Form
""
;... .-.',;*-.'.r. '^v.'fe. ; '-^
Pollutant Pathway Record For IAQ Profiles
Building Araa
(zone, room}
-
Usซ
Intended Pressure
Positive Negative
(+1 W
. ^
Needs
Attention?
(V/NJ
Comments
-.- . ,-,-ii'i, , ' - ->iS sir ----- '' -. -.-:i-f --!*,ป: ^..--^iij'tei,,;- -.r
equipment and make sure that it is in good
operating condition. A portion of the
HVAC Checklist - Short Form is shown
on this page, wMi the entire form repro-
duced in Tab V. The HVAC Checklist -
Long Form (also reproduced in Tab V) is
recommended where a more detailed
examination is needed. You may want to
create a new form incorporating elements
from your existing inspection forms.
Identify items of equipment that need to
be repaired, adjusted, or replaced. Record
control settings and operating schedules for
HVAC equipment for comparison to
occupancy schedules and current uses of
space.
Inventory pollutant pathways
Using the sketch plan of the building
that was begun during the walkthrough
inspection, indicate architectural
connections (e,g.,. chases) and mechanical
connections (e.g., ductwork, temperature
control zones). Observe and record airflow
between spaces intended to run positive or
negative and the that surround them
(including airflow between perimeter
rooms and outdoors). Note that hidden
pathways such as chases may travel both
vertically and horizontally and transport
pollutants over long distances. Record the
results on flie Pollutant Pathway Record
for IA.Q Profiles, the sketch plan, or both.
The form is shown at the left (and in Tab
V), and a sample sketch plan is shown on
the opposite page.
Inventory pollutant sources
Use the Pollutant and Source
Inventory (shown in part on page 28 and
reproduced in Ml in Tab V) to record
potential pollutant sources in the building.
As you fill out the inventory form, note the
locations of major sources. Major sources
such as large items of equipment can be
recorded on the floor plan. The Chemical
Inventory Form (shown on page 28 and
reproduced in Tab V) can be used to record
the names and locations of chemicals or
hazardous substances used or stored within
26 Section 4
-------
>4 f/re escape floorplan /s
very useful for recording
information collected
during IAQ profile develop-
ment or while investigating
IAQ complaints. The facility
manager has begun to
identify the areas in which
air pressure relationships
are (or should be) control-
led and some ventilation
and has noted source infor-
mation. Symbols are ฉ for
negative pressure, @ for
positive pressure, and ^
for observed direction of
airflow. Utility chases,
tunnels, and suspended
ceilings could also be
drawn in to show pollutant
pathways and driving
forces.
Developing an IAQ Profile 27
-------
Sample Form
Pollutant and Source Inventory
I " ; v 4. '}" _ .,.:.' - ... :... ^LJ^! >k _- N _ J? ^ ^ -ซ ji $t H Lฃt ^ ,4-
f - .*. - ., ,. - -.,. . ._=F= --= .==-- J? U ' r f
Usfng the Hst of potential source categories below, record any
Indfaatlgns.of contamination or suspected pollutants that may
require farther investigation or treatment.
" '" ' *
Source Category
Chocked
Needs Attention
Location
Comments
SOURCES OUTSIDE THE BUILDING
Contซmlnated Ambient Air
Pollen, dust
Industrial
contaminants
General vehicular
contaminants
-
Samplซ Form
,ซ .ป * ,,. ปปปi i ซt
Chemical Inventory Form
Tha inventory should include chemicals stored or used in the
building for cleaning, maintenance, operations, and pest control.
if you hava an MSpSJMaterial Safety Data Sheet) for the chemical,
put a check mark in the right-hand column. If not, ask the chemical
supplier to provide the MSDS, if one is available.
D*t*
Chamlcal/
Brand Name
Use
Storag*
Location(s)
MSDS
on File?
'
SEE
, COMPLETE
FORMS
PAGES 213
"AND 221
the building, such as those that may be
contained in cleaning materials, biocides,
paints, caulks, and adhesives. Ask your
suppliers to provide you with Material
Safety Data Sheets.
You may be unaware of the potential
hazards of some materials that are
commonly used in pubEc and commercial
buildings. For example:
In 1990, EPA eliminated the sale of
mercury-containing interior latex paint.
(Enamel paints do not contain mercury.)
People are urged not to use exterior latex
paint indoors, as it may contain mercury.
If you have paint in storage that may
have been manufactured before August
20,1990, you may contact the
manufacturer, the National Pesticide
Telecommunication Network (1-800-
858-7378), or your State Health
Department for guidance.
In 1990, EPA banned the use of
hexavalent chromium chemicals in
cooling towers, because the chemicals
have been shown to be carcinogenic.
Heating system steam should not be used
in the HVAC humidifican'on system, as
it may contain potentially harmful
chemicals such as corrosion inhibitors.
Collect information on building
occupancy
The Zone/Room Record shown on the
following page (and also reproduced in
Tab V) can be used during IAQ profile
development to maintain an up-to-date
record of the way each area of the building
is used, its source of outdoor air, and
whether or not it is equipped with local
exhaust. If underventilation is suspected,
the form can be used to estimate ventila-
tion rates in cubic feet per minute per
person or per square foot floor area, for
comparison to guidelines such as design
documents, applicable building codes, or
the recommendations of ASHRAE 62-
1989 (see the table that is reproduced in
Appendix B).
28 Section 4
-------
|; Sample Form
|U Zone/Room Record
EjThis form is to be used differently depending on whether the goal is to prevent or diagnose IAQ problems.
|l During development of a profile, this form should be used to record more general Information about the entire
p building; during an investigation, the form should be used to record more detailed information about the
I - complaint area and areas surrounding the complaint area or connected to it by pathways.
PROFILE AND DIAGNOSIS INFORMATION
Building Area
(Zone/Room)
Use*ซ
Source of
Outdoor Air*
Mechanical
Exhaust?
{Write "No"
or estimate
cfm airflow}
Comments
DIAGNOSIS INFORMATION ONLY
Peak Number of
Occupants or
Sq. ft Floor Area**
Total Air
Supplied
(In cfm)ป**
Outdoor Air
Supplied
per Person or
per 150 Sq.
Ft. Area****
Underventilation problems can occur
even in areas where ventilation rates
apparently meet ASHRAE guidelines;
proper distribution and mixing of supply
air with room air are also essential for
good ventilation.
If the information collected as you
develop the IAQ profile indicates that you
have one or more IAQ problems, Sections
6-8 provide guidance to help you deal with
them. If you need to prioritize these prob-
lems, consider the apparent seriousness of
their consequences. For example, combus-
tion gas odors demand a more rapid
response than thermostats that are out of
calibration.
Developing an IAQ Profile 29
-------
Page Intentionally Blank
-------
Managing Buildings for Good iAQ
he relationships among building owners,
management, staff, and occupants are an
important factor in decisions that affect
indoor air quality. The objectives of the
major players in these relationships may be
very different. Occupants want the
building to be pleasant, safe, and attractive;
if they are paying tenants, they also want
to get the maximum use out of the space
they rent for the least cost. Building
owners and management want to maintain
a reputation for providing quality property
at reasonable cost, but also need to derive a
profit. Facility staff are often caught in the
middle, trying to control operating and
maintenance costs while still keeping
occupants satisfied.
Regardless of the points on which they
may disagree, building occupants, staff,
and management share the goal of provid-
ing a healthy indoor environment. Recog-
nition of this common goal may help avoid
conflict when discussing lAQ-related
policies.
Any IAQ management system will be
successful only if it is organized to fit your
specific building. It would not be appropri-
ate for this document to prescribe any
single approach. However, the skills
associated with IAQ management activities
will be identified to help building manage-
ment decide who will be best able to carry
them out Education and training programs
for staff and building occupants should be
provided to ensure that new procedures are
understood and adopted.
Managing a building for good indoor air
quality involves reviewing and amending
current practice (and establishing new
procedures, if necessary) to:
Operate and maintain HVAC equipment
keep all equipment and controls in proper
working order
keep interior of equipment and ductwork
clean and dry
Oversee activities of staff, tenants, contrac-
tors, and other building occupants that
impact indoor air quality
smoking
housekeeping
building maintenance
shipping and receiving
pest control
food preparation and other special uses
Maintain communications with occupants
so that management will be informed of
complaints about the indoor environment
in a timely way
identify building management and staff
with IAQ responsibilities
use health and safety committees
Educate staff, occupants, and contractors
about their responsibilities in relation to
indoor air quality
m staff training
lease arrangements
contracts
Identify aspects of planned projects that
could affect indoor air quality and
manage projects so that good air quality
is maintained
redecorating, renovation, or remodeling
relocation of personnel or functions
within the building
new construction
DEVELOPING AN IAQ
MANAGEMENT PLAN
The chart on page 32 shows the elements
of an IAQ management plan. Develop-
ment of the management plan involves
reviewing and revising staff responsibili-
ties so that IAQ considerations become
incorporated into routine procedures.
IAQ management
systems will only be
successful if they are
organized to fit your
specific building.
Managing Buildings for Good IAQ 31
-------
Organizations may assign responsibility for
operations, recordkeeping, purchasing,
communications, planning, and policy-
making in many different ways. However,
the key elements of good IAQ management
remain the same:
Reach an understanding of the funda-
mental influences that affect Indoor air
quality in your building by:
becoming familiar with literature on IAQ
keeping abreast of new information
Select am JAQ manager with:
clearly defined responsibilities
adequate authority and resources '
FIGURE 5-1: Developing an IAQ Management Plan
START
Select an IAQ Manager
Review IAQ Profile
and Existing Records
Assign Staff
Responsibilities/Train Staff
Facilities Operation
and Maintenance
Housekeeping
Pest Control
Tenant Relations
Renovation
Redecorating
Remodeling
Smoking
Use the IAQ profile and other available
information to:
evaluate the design, operation, and usage
of the building
identity potential IAQ problem locations
identify staff and contractors whose
activities affect indoor air quality
Review and revise staff responsibilities to
ensure that responsibilities that may affect
indoor air quality are clearly assigned. In
addition, establish lines of communication
for sharing information pertaining to:
equipment in need of repair or
replacement
plans to remodel, renovate, or redecorate
new uses of building space or increases in
occupant population
installation of new equipment
Renew standard procedures and make
necessary revisions to promote good
indoor mr quality, such as:
terms of contracts (e.g., pest control,
leases)
scheduling of activities that produce dust.
emissions, odors
scheduling of equipment operation,
inspection, and maintenance
specifications for supplies (e.g., cleaning
products, construction materials, furnish-
ings)
policy regarding tobacco smoking within
the building
Review the existing recordkeeping system
and make necessary revisions to;
establish a system for logging IAQ-
related complaints
obtain Material Safety Data Sheets for
hazardous materials used and stored in the
building
Educate building staff, occupants, and
contractors about their influence on
indoor air quality by:
m establishing a health and safety committee
instituting training programs as needed
32 Sections
-------
IAQ problems may occur even in
buildings whose owners and managers
conscientiously apply the best available
information to avoid such problems.
Those who can demonstrate their ongoing
efforts to provide a safe indoor environ-
ment are in a strong legal and ethical
position if problems do arise,
Select an IAQ Manager
IAQ management will be facilitated if one
individual is given overall responsibility
for IAQ. Whether or not this person is
given the title of "IAQ Manager," he or
she should have a good understanding of
the building's structure and function and
should be able to communicate with
tenants, facility personnel, and building
owners or their representatives about IAQ
issues.
The IAQ manager's ongoing responsi-
bilities might include:
developing the IAQ profile
overseeing me adoption of new
procedures
establishing a system for communicating
with occupants about IAQ issues
coordinating staff efforts that affect
indoor air quality, and making sure that
staff have the information (e.g., operat-
ing manuals, training) and authority to
carry out their responsibilities
reviewing all major projects in the
building for their IAQ implications
reviewing contracts and negotiating with
contractors (e.g., cleaning services, pest
control contractors) whose routine
activities in the building could create
IAQ problems
periodically inspecting the building for
indicators of IAQ problems
managing lAQ-related records
responding to complaints or observations
. regarding potential IAQ problems
conducting an initial walkthrough
investigation of any IAQ complaints
RODUCTS OF THE REVIEW OF THE IAQ PROFILE
OTHER EXISTING RECORDS
fS "priority list of locations and activities within the building that
recjuire special attention in order to prevent indoor air quality
sj^sj of staff and contractors whose responsibilities need to be
fjncjuded in the IAQ management plan
Review IAQ Profile and Other
Existing Records
If the IAQ manager was not actively
involved in developing the IAQ profile,
one of the first tasks will be to review the
profile carefully. The manager can start by
also identifying building locations with a
potential for IAQ problems, staff and
contractors whose activities impact indoor
air quality, and other building occupants
whose activities impact indoor air quality.
In addition to information from the IAQ
profile, it may be helpful to review lease
forms and other contractual agreements for
an understanding of the respective legal
responsibilities of the building manage-
ment, tenants, and contractors. Incorpora-
tion of IAQ concerns into legal documents
helps to ensure the use of proper materials
and procedures by contractors and can help
to limit the load placed on ventilation
equipment by occupant activities.
Assign Responsibilities/
Train Staff
The assignment of responsibilities varies
widely between organizations, depending
upon the routine activities to be carried out
.and the capabilities of the available
personnel. It would not be appropriate for
this document to suggest how lAQ-related
responsibilities should be allocated in your
organization. For example, issues of
access in buildings with tenant-occupied
space highlight the need for cooperation
between building managers and the
IAQ management will
be facilitated if one
Individual is given
overall responsibility
for IAQ.
Managing Buildings for Good IAQ 33
-------
A clean mechanical room,
free oftracked-in dirt and
stored chemicals, is an
Important element in the
prevention of indoor air
quality problems. Airborne
contaminants in the
mechanical room can be
drawn Into ductwork
through return air openings
or unsealed seams in return
ducts and circulated
throughout the building.
tenants* office managers. The building
staff may be limited in its access to tenant
spaces and tenants may not have access to
building operations areas such as mechani-
cal rooms, yet both tenants and building
management have responsibilities for
maintaining good indoor air quality.
Facility personnel are not generally
trained to think about IAQ issues as they
go about then* work. Even though building
staff may be observing events and condi-
tions that would indicate potential prob-
lems to an experienced IAQ investigator,
the staff member's attention may be
directed elsewhere. As new practices are
introduced to prevent indoor air quality
problems, an organized system of
recordkeeping will help those practices to
become part of routine operations and to
"flag" decisions that could affect IAQ
(e.g., renovations, new tenants). The best
results can be achieved by taking time to
think about the established channels of
communication within your organization,
so that new forms can be integrated into
deeisionmaking with minimum disruption
of normal procedures.
Using information from the IAQ
profile, the IAQ manager should work
with staff and contractors to ensure that
building operations and planning processes
incorporate a concern for indoor air
quality. New procedures, recordkeeping
requirements, or staff training programs
may be needed. (Growing interest in IAQ
is stimulating government agencies and
private sector organizations to develop
training programs. See Appendix G for
additional information,) The flow of
information between the IAQ manager and
staff, occupants, and contractors is
particularly important. Good indoor air
quality requires prompt attention to
changing conditions that could cause IAQ
problems, such as installation of new
equipment or furnishings, increases in
occupant population, or new uses of
rooms.
Facility Operation and Maintenance
Indoor air quality can be affected both
by the quality of maintenance and by the
materials and procedures used in operating
and maintaining the building components
including the HVAC system.
Facility staff who are familiar with
building systems in general and with the
features of their building in particular are
an important resource in preventing and
resolving indoor air quality problems.
Facility personnel can best respond to
indoor air quality concerns if they under-
stand how their activities affect indoor air
quality. It may be necessary to change
existing practices or introduce new
procedures in relation to:
Equipment operating schedules: Confirm
that the timing of occupied and unoccu-
pied cycles is compatible with actual
occupied periods, and that the building is
flushed by the ventilation system before
occupants arrive. ASHRAE 62-1989
provides guidance on lead and lag times
for HVAC equipment. In hot, humid
34 Sections
-------
climates, ventilation may be needed during
long unoccupied periods to prevent mold
growth.
Control of odors and contaminants;
Maintain appropriate pressure relationships
between building usage areas. Avoid
recircolating air from areas that are strong
sources of contaminants (e.g., smoking
lounges, chemical storage areas, beauty
salons). Provide adequate local exhaust
for activities that produce odors, dust, or
contaminants, or confine those activities to
locations that are maintained
negative pressure (relative to adjacent
areas). For example, loading docks are a
frequent source of combustion odors.
Maintain the rooms surrounding loading
docks under positive pressure to prevent
vehicle exhaust from being drawn into the
building. Make sure that paints, solvents,
and other chemicals are stored and handled
properly, with adequate (direct exhaust)
ventilation provided. If local filter
and adsorbents are used, Ihey require
regular maintenance. Have vendors
provide Material Safety Data Sheets
(MSDSs).
Ventilation quantities: Compare outdoor
air quantities to the building design goal
and local and State building codes and
make adjustments as necessary. It is also
informative to' see how your ventilation
rate compares to ASHRAE 62-1989,
because that guideline was developed with
the goal of preventing IAQ problems.
(Note: Increasing ventilation quantities to
meet ASHRAE guidelines may exceed the
capacity of HVAC equipment to condition
the air.)
HVAC equipment maintenance sched-
ules: Inspect all equipment regularly (per
recommended maintenance schedule) to
ensure that it is in good condition and is
operating as designed (i.e., as close to the
design setpoints for controls as possible),
Most equipment manufacturers provide
recommended maintenance schedules for
their products. Components that are
exposed to water (e.g,, drainage pans,
coils, cooling towers, and humidifiers)
require scrupulous maintenance to prevent
microbiological growth and the entry of
undesired microbiologicals or chemicals
into tiie indoor airstream,
HVAC inspections: Modify the HVAC
Checklists (reproduced in Tab V) as
necessary so that they are appropriate for
inspection of the specific equipment in
your building. Be thorough in conducting
these inspections. Items sucli as small
exhaust fans may operate independently
from the rest of the HVAC system and are
often ignored during inspections. As
equipment is added, removed, or replaced,
document any changes in function,
capacity, or operating schedule for future
reference. It may also be helpful to store
equipment manuals and records of equip-
ment operation and maintenance in the
same location as records of occupant
complaints for easy comparison if IAQ
problems arise.
Building maintenance schedules: Try
to schedule maintenance activities that
interfere with HYAC operation or produce
odors and emissions (e.g., painting, roofing
operations) so that they occur when the
building is unoccupied. Inform occupants
when such activities are scheduled and, if
possible, use local ventilation to ensure
that dust and odors are confined to the.
work area. , -
Purchasing: Review the general informa-
tion provided by MSDS and request
information from suppliers about the
chemical emissions of materials being
considered for purchase.
Note: At present there; is no general .
system for certifying or labeling low-
emission products nor is there a standard
procedure for;building managers to use in
gathering emissions data on products they
are considering for purchase. Limited
information on materials such as
Be thorough in
conducting HVAC
inspections. Items
such as small exhaust
fans may operate
independently from
the rest of the system
and are often ignored
during Inspections.
Managing Buildings for Good IAQ 35
-------
PREVENTIVE
i. An HVAC system requires adequate preventive maintenance (PM)
~- and prompt attention to repairs in order to operate correctly and
provide suitable comfort conditions and good indoor air quality.
The HVAC system operator(s) must have an adequate understand-
ing of the overall system design, its intended function, and its
; limitations. The preventive maintenance program must be prop-
- erly budgeted and implemented, not merely planned on paper.
A wejj-impiamented PM plan will improve the functioning of the
mechf nteal systems and usually save money when evaluated on a
^ life-cycle basis. However, in some buildings, because of budgetary
I* g-oflsiritlfrts, maintf nancfjs pyt off until breakdowns occur or
^ complaints arise, following the "if it isn't broken, don't fix it"
: philosophy. This type of program represents a false economy and
oftan fnc,reases the eventual cost of repairs.
_ : s. ^.Zii^ -,. , '.--,. :> Wife -H * ' -' l> ซ -^'^ ..,.-< ,,*'.. !,, , ;, =. -,.!> ..-*<*
ง Poor filter maintenance is a common example of this phenom-
|i"anohป filters that are not changed regularly can become a bed for
S fungal growth, sometimes allowing particles or microorganisms to
ba dist|}butedMwtttillB,tbe_t>ul!dlng. When filters become clogged,
t _.' thf fflns J4S6 more energy to operate and move less air. If the filters
l^ar^anipjixpansive, low-efficiency type that becomes clogged and
"blows out," the coils, then accymujale dirt, causing another
^Increase In energy consumption. Poor air filter efficiency and poor
r mafptsnf pea may eause.dlrt to build up in ducts and become
.'" confarrilnated with mbld,st possibly requiring an expensive duct
L eleanlng'operatlon, v t ^u ., ,
** Qenwsi elements of a P^! plan include:
j_. periodic inspection, cleaning, and service as warranted
-. m adjustment and calibration of control system components
maintenance equipment and replacement parts that are of good
quality and properly selected for the Intended function
Critical HVAC system components that require PM In order to
maintain comfort and deliver adequate ventilation air include:
. * outdoor air Intake opening
j f to damper controls
",tHsSf fillers . -, . - -.. -
m drip pans
"" M cooling and heating colls
ป fan bซ)ts , ,,,.ปป, ,.,.^,..-. :
ฃ% humldiflcation equipment and controls
^"distribution systems . ,,...,
~m exhaust fans . .. ,., ..,;.,.: ., ....-.
Somt private sector organizations have developed guidance on
\ -, preventive maintenance. {See discussion in Guidelines of Care
1 Trsda Associations on page 43.)
pressed-wood products is available, and
more may be expected in the future,
Public and private sector organizations are
working to develop product testing
procedures for acceptance by such organi-
zations as the American Society for
Testing and Materials (ASTM),
Preventive maintenance management:
Maintenance "indicators" are available to
help faciEty staff determine when routine
maintenance is required. For example, air
filters are often neglected (sometimes due
to reasons such as difficult access) and fail
to receive maintenance at proper intervals.
Installation of an inexpensive manometer,
an instrument used to monitor the pressure
loss across a filter bank, can give an
immediate indication of filter condition
without having to open the unit to visually
observe the actual filter.
Computerized systems are available that
can prompt your staff to carry out mainte-
nance activities at the proper intervals.
Some of these programs can be connected
to building equipment so that a signal is
transmitted to your staff if a piece of
equipment malfunctions. Individual
can be monitored for temperature, air
movement, humidity, and carbon dioxide,
and new sensors are constantly entering the
market. These sensors can be programmed
to record data and to control multiple
elements of the HVAC system.
Housekeeping
Indoor air quality complaints can arise
from inadequate housekeeping that fails to
remove dust and other dirt. On the other
hand, cleaning materials themselves
produce odors and emit a variety of
chemicals.
As they work throughout your building,
cleaning staff or conttactors may be the
first to recognize and respond to potential
IAQ problems. Educate them about topics
such as the following:
36 Sections
-------
Cleaning schedules: Consider how
cleaning activities are scheduled. Manag-
ers may want to schedule the use of some
cleaning agents that introduce strong odors
or contaminants during unoccupied
periods. However, make sure that fumes
from cleaning products are eliminated
before air handling systems switch to their
"unoccupied" cycles.
Purchasing: Become more familiar with
the chemicals in cleaning and maintenance
products and their potential toxicity.
Select the safest available materials that
can achieve your purpose. Review the
information provided by product labels
and Material Safety Data Sheets. Request
information from suppliers about the
chemical emissions of products being
considered for purchase.
Materials handling and storage: Review
the use of cleaning materials to ensure
proper use and storage.
Trash disposal: Follow proper trash
disposal procedures. If there is a restau-
rant in the building, require daily pick-up
of perishable refuse. Ensure that the
containers are covered, pest control is
effective, and that the trash collection area
is cleaned at least daily.
Shipping and Receiving
Shipping and receiving areas can create
indoor air quality problems regardless of
the types of materials being handled.
Vehicle exhaust fumes can be minimized
by prohibiting idling at the loading dock.
This is particularly important if the loading
dock is located upwind of outdoor air
intake vents. You can also reduce drafts
and poEutant entry by pressurizing interior
spaces (e.g., corridors) and by keeping
doors closed when they are not in use.
,4 good preventive maintenance
program can help a facility manager
identify and correct problems before
they occur. If this fan belt breaks, the
area served by the air handling unit may
'be without ventilation. If it is slipping, it
Is already reducing the airflow.
A termitfcide misapplication resulted in
an indoor air quality problem in this
school. Detectable levels ofchlordane
were found in both wipe {surface} and
air samples near the injection holes
drilled into the ground floor. Note the
small white circles near the wall, (Under
an agreement with EPA, manufacturers
have withdrawn chlordane from sale.)
Proper application methods are
important for all pesticides.
Managing Buildings for Good IAQ 37
-------
ik: ฃ&
to
cQnrornten_dg^.|o prevent unacceptable levels of pests, while
, property, and the
ifjrigst cost-effective rnetns._}PM, uses a
sanitation, monitoring, habitat
judicious application of pesticides when
.
irnprovfd sanitation Jง.g., removing food from desks, cleaning)
" in/md WPP^QJlOfl ฐ^ Pest population sites
l waste (e.g., keeping refuse in tight containers, locating
~* ~ ' buflding if possible)
|.g:, fixing leaking pipes promptly.
i OTdjnpvernerit {eปg.,
-.-
clutter, relocating outside light :
;, snap traps, and glue boards)
-v^'-a
pest management
j wfifi prevejtiyejrtalntenangejtJiousekf eplng practices,
Wo, occupant education, and staff training.
ฃH* -
Pest Control
Pest control activities that depend upon
the use of pesticides involve the storage,
handling, and application of materials that
can have serious health effects. Common
construction, maintenance practices, and
occupant activities provide pests with air,
moisture, food, warmth, and shelter.
Caulking or plastering cracks, crevices, or
holes to prevent harborage behind walls
can often be more effective man pesticide
application at reducing pest populations to
a practical minimum.
Integrated Pest Management (IPM) is a
low-cost approach to pest control based
upon knowledge of the biology and
behavior of pests. Adoption of an IPM
program can significantly reduce the need
for pesticides by eliminating conditions
that provide attractive habitats for pests.
If an outside contractor is used for pest
control, it is advisable to review the terms
of the contract and include IPM principles
where possible. The following items
deserve particular attention.
Pest control schedule; Schedule pesticide
applications for unoccupied periods, if
possible, so that the affected area can be
flushed with ventilation air before occu-
pants return. Pesticides should only be
applied in targeted locations, with mini-
mum treatment of exposed surfaces. They
should be used in strict conformance with
manufacturers* instructions and EPA
labels. General periodic spraying may not
be necessary. If occupants are to be
present, they should be notified prior to the
pesticide application. Particularly suscep-
tible individuals could develop serious
illness even though they are only mini-
mally exposed.
Materials selection, handling, and
storage: Select pesticides that are species-
specific and attempt to minimize toxicity
for humans and non-target species. Ask
contractors or vendors to provide EPA
labels and MSDSs. Make sure that
pesticides are stored and handled properly
consistent with their EPA labels.
Ventilation of areas where pesticides are
applied: If only limited areas of the
building are being treated, adjust the
HVAC system so that it does not distribute
contaminated air throughout the rest of the
building. Consider using temporary
exhaust systems to remove contaminants
during the work. It may be necessary to
modify HVAC system operation during
and after pest control activities (e.g.,
running air handling units on 100%
outdoor air for some period of time or
running the system for several complete air
exchanges before occupants re-enter the
treated space).
38 Sections
-------
flWIATlBIAL SAFETY Under OSHA regulations, responsible parties are required to document information on
tpATA SHEETS potentially hazardous products. These Material Safety Data Sheets (MSDSs) may be
ฃ *" of limited help in identifying some products that may pose IAQ concerns. However,
f-_ * professional judgment and collection of additional information may be necessary in
f^ . order to make full use of the MSDS. The following table summarizes some of the
ฃ:_" issues to keep in mind when deciding whether information from MSDSs is applicable
fc-- 'to emission sources^and exposures of concern in a building.
1
'.Item
Substances Covered
Possible Uses
MSDSs may identify significant
airborne contaminants
Comments
\v t~ "' * -f
MSDSs may not be available onsite for
, jnapy products
-Lspme components are listed as
''I jsroprletary and are not disclosed
; MjSPjSs <|o not always highlight products
"" most,likely to be airborne
^eonta/nfnanl: byproducts inadvertently
""*/ ^formed during manufacture won't always
*" be listed
Personal Protection/
First Aid
i may suggest precautions for
'conducting source inspection
i usually relates only to high-level, worst-
casง exposures in general industry
Health Effects
generally presents types of health
effects that may be expected primar-
ily at high level (e.g., industrial)
exposures -
i symptoms listed may not occur at low-
level concentrations found in indoor air
i MSDSs may not include more subtle IAQ
aspects such as nuisance factors and
sensitivity to mixtures
I Physical Data
odor description may help identify
sources
volatility may suggest which prod-
ucts are likely to be airborne
p contaminants to expect in event of a
fire or decomposition may be listed
reactivity data may suggest potential
problems with storage or use
reference material on how to use physical
datajnformation to predict IAQ impacts
may be scarce
I Control Measures
identifies proper storage and
packaging procedures
identifies steps for cleanup of gross
spills
many office chemicals are kept in much
smaller amounts than found in industrial
settings
spill cleanup may not eliminate airborne
- contamination.
does not.specify routine emission controls
A reasonable effort should be made to collect available MSDSs during IAQ profile
development. Care should be taken to consider information that is relevant to IAQ
concerns. Other important indicators of how a particular product may affect IAQ are
available from direct odor and dust observations, a review of work practices, and
interviews with operators and occupants. The manufacturer is a good source of follow-
up information on a given product (phone number should be included on each MSDS).
Managing Buildings for Good IAQ 39
-------
It is important for building
occupants to understand
that their activities can
create Indoor air quality
pro/Warns, Smoking
raleases both carcinogenic
and irritating substances
Into the air.
Occupant Relations
Managing occupant relations to prevent
IAQ problems invokes: allocating space
and monitoring the use of building to
isolate odor- and contaminant-producing
activities and avoid re-entrainment; estab-
lishing a communication strategy that is
responsive to complaints and provides
tenants with information about their role in
preventing indoor air quality problems;
and modifying employee manuals or lease
agreements as necessary to clarity the
responsibilities of occupants and building
management. A health and safety commit-
tee or joint tenant-management IAQ task
force that represents all of the major inter-
est groups in the building can be very
helpful in disseminating information and
fostering a cooperative approach to IAQ
management. See Section 3 for a discus-
sion of these points.
Renovation, Redecorating, and
Remodeling
Renovation, redecorating, and re-
modeling activities can create indoor air
problems by producing dust, odors, micro-
biologicals and spores, and emissions.
It is difficult to prevent IAQ problems if
some building areas are undergoing reno-
vation while adjoining areas continue
normal operations.
Close monitoring of renovation,
redecorating, and remodeling projects is
recommended. The following suggestions
may be helpful:
Working with professional consultants:
Communicate your concern about prevent-
ing indoor air quality problems to die
engineer, architect, interior designer, or
other professionals involved in the project.
Product selection; Specify products and
processes that minimize odors and emis-
sions, while maintaining adequate safety
and efficacy. Review the general informa-
tion provided by the product labels and
MSDSs. Request information from
suppliers about the chemical emissions of
products being considered for purchase.
Work schedules: Schedule activities that
produce dust, odors, or emissions for
unoccupied periods if possible.
Isolation of work areas; Block off return
registers so that contaminants are not
reeirculated from the demolition/construc-
tion area into adjoining areas, and install
temporary barriers to confine and
noise. If possible, install temporary local
exhaust to remove odors and contaminants,
and check to confirm that the temporary
ventilation system is operating as planned.
Installation of new furnishings: Ask
suppliers to store new furnishings in a
clean, dry, ventilated location so that
volatile organic compounds will be emitted
before installation. Minimize the use of
adhesives during installation or specify
low-emitting products. After new furnish-
ings are installed, increase the ventilation
rate to flush the area with outdoor air and
dilute emissions.
Smoking
Although there are many potential
sources of indoor air pollution, both
research and field studies have shown that
environmental tobacco smoke (ETS) is one
of the most widespread and harmful indoor
air pollutants. Environmental tobacco
smoke is a combination of sidestream
4O Sections
-------
smoke from the burning end of the
cigarette, pipe, or cigar and the exhaled
mainstream smoke from the smoker. ETS
contains over 4,000 chemicals; 43 of these
chemicals are known animal or human
carcinogens. Many other chemicals in
ETS are tumor promoters, tumor initiators,
co-carcinogens (i.e., chemicals that are
able to cause cancer when combined with
another substance), or cancer precursors
(Le., compounds that can make it easier to
form other carcinogenic chemicals).
In 1986, The Health Consequences of
Involuntary Smoking: A Report of the
Surgeon General on Environmental
Tobacco Smoke concluded that ETS was a
cause of lung cancer in healthy non-
smokers and that "the scientific case
against involuntary smoking as a public
health risk is more than sufficient to justify
appropriate remedial action, and the goal
of any remedial action must be to protect
the non-smoker from environmental
tobacco smoke." In the same year, the
National Research Council of the National
Academy of Sciences issued a report,
Environmental Tobacco Smoke: Measur-
ing Exposures and Assessing Health
Effects, which also concluded that passive
smoking increases the risk of lung cancer
in adults.
In June 1991, NIOSH issued a Current
Intelligence Bulletin (#54) on ETS in the
workplace that dealt with lung cancer and
other health effects. In its Bulletin,
NIOSH stated that the weight of evidence
is sufficient to conclude that ETS can
cause lung cancer in non-smokers.(Le.,
those who inhale ETS). It recommended
that the preferable method to protect non-
smokers is the elimination of smoking
indoors and that the alternative method is
to require that smoking be permitted only
in separately ventilated smoking areas.
The NIOSH Bulletin emphasized that
provision of such isolated areas should be
viewed as an interim measure until ETS
can be completely eliminated indoors.
PRODUCTS OF THE ASSIGNMENT OF
RESPONSIBILITIES AND REVIEW OF THAI I
:p$|?l s^<* ~ ~ "- - '
^Jfeli*>..' .. . , *, .- , !,,..-,
f*'m job descriptions and/or contracts, work procedures, and
RuTschedules revised to reflect indoor air quality concerns
'procedures^for reviewing purchases of supplies^ hew projects,
^E Contracts, and 'policies inf relation to indoor airDuality "
jiQking policy revisions, if necessary
tw'pians for educating occupants and training staff training in
relation to indoor air quality
.1
Smoking areas must be separately
ventilated, negatively pressurized in
relation to surrounding interior spaces, and
supplied with much more ventilation than
non-smoking areas. TheNIOSH Bulletin
also recommends that the air from the
smoking area should be exhausted directly
outdoors and not recirculated within the
building or vented with the general exhaust
for the building. ASHRAE Standard 62-
1989 recommends that smoking areas be
supplied with 60 cubic feet per minute (60
cfm) per occupant of outdoor air; the
standard also recognized that using transfer
air, which is puEed in from other parts of
the building, to meet the standard is
common practice.
Both EPA and NIOSH advise that
building owners or facility managers
considering the introduction of smoking
restrictions should implement smoking
cessation programs. In addition, employ-
ees and labor unions should be involved in
the development of non-smoking policies
in the workplace.
(Refer to Appendix G for citations on
publications mentioned in this section,
especially NIOSH Current Intelligence
Bulletin (#54): Environmental Tobacco
Smoke in the WorkplaceLung Cancer
and Other Health Effects. Additional
resources on ETS, including an assessment
of respiratory disorders in children and
lung cancer risks in adults, and a guide to
developing effective smoking policies, will
be available from EPA early in 1992.)
According to a 1986
report of the Surgeon
General, "the case
against involuntary
smoking is more than
sufficient to justify
appropriate remedial
action to protect the
non-smoker from
environmental tobacco
smoke."
Managing Buildings for Good IAQ 41
-------
Samp!* Form
Management Checklist
Item
Date Begun
or Completed
(as applicable)
Responsible Person
{name, telephone)
Location
("MA" if the item is not
applicable to this building)
IAQ PROFILE
Collect and Review
Existing Records
HVAC design data, operating
instructions, and manuals
HVAC maintenance and calibration
records, testing and balancing reports
Inventory of locations where
occupancy, equiptment, or building
use has changed
Invontory of complaint locations
Conduct a Walkthrough
Inspection of the Building
List of responsible staff and/or
contractors, evidence of training,
and job descriptions
Identification of areas where positive
or negative pressure should be
maintained
The IAQ Management Checklist
shown in part here and included in full
within Tab V can be used to help
confirm that you have accounted for the
major factors that could cause IAQ
problems in your building.
42 Sections
-------
GUIDELINES OF
CARE DEVELOPED
I BY TRADE
fe ASSOCIATIONS
The following associations have developed guidelines of care that may have a
direct or indirect impact on indoor air quality. These standards are described
below so that building management may become aware of them. Neither EPA
nor NIOSH endorse these standards.
Air Conditioning
: Contractors of
-^, . , ,-* f . , -.. ' ., *ป
Technical Reference Bulletin Series. Indoor air quality is one of the topics covered
in this series of technical bulletins on heating, ventilation, and air conditioning
(HVAC). Bulletins can be filed in the At^CA Technical Reference Notebook, The Air
Side Design tab of the notebook includes bulletins devoted to Indoor air quality
control. ' " " " '** -----.
'
Air-Conditipning and
Refrigeration institute
(AFM)
*$. ;.ซui
",-? 1
Air Conditioning and Refrigeration Equipment General Maintenance Guidelines for
Improving the Indoor Environment (1991!, General maintenance requirements for
heating ventilation, air conditioning, and refrigeration (HVACR) equipment.
Specific equipment/component maintenance is given for the following: air cleaning
systems; durts; registers/diffusers and air terminals; dampers/economizers; drain
pans; air handlers; humidifiers; package terminal units; and evaporator, condenser,
hydronlc and economizer coils. The guidelines do not supersede any maintenance
instructions that are provided by the manufacturer. In addition, the Institute has
Issued an Indoor Air Quality Briefing Paper that addresses the interactions
between HVACR equipment and the quality of indoor air.
" '
Associated Air
~ Balance Council
r (AABC)
"' " , - ' * " "'-'"',,' ^-.' '"".,. -. ',-.-' >l/ W':*.'-),Xfr- K',f;:,"tJ^"tr^
National Standards for Testing and Balancing Heating,Ventilation, and Air Condi-
tioning Systems (1989). Establishes a minimum set of field testing and balancing
standards and provides comprehensive and current data on testing and balancing
HVAC systems. Chapters receiving special attention include Cooling Tower
Performance Tests, Sound Measurements, Vibration Measurements, Fume Hoods,
and AABC General Specifications. The book contains a complete index to the
technical data provided.
* * " ' ' ' ' * * " ' " ^ ~ * ' *
National
Environmental
Balancing Bureau
(NEBB)
Procedural Standards for Testing, Adjusting, and Balancing of Environmental
Systems (1991). A "how-to" set of procedural standards that provide systematic
methods for testing, adjusting, and balancing (TAB) of HVAC systems. Includes
sections on TAB instruments and calibration, report forms, sample specifications,
* and engineering tables and charts. A valuable innovation is the "Systems Ready
jo balance" start-up checklist to help organize jobs systematically. Other features
include: additional engineering data; condensed duct design tables/charts; hy-^
dronic design tables/charts; and pertinent HVAC equations in U.S. and metric units.
- National Pest Control
Association
(NPCA)
.Good Practice Statements, Periodically updated, officially approved and adopted
by the Association's Board of Directors, these "Good Practice Statements" are
designed as guidelines for performing various services rather than standards of
operation. In addition, the Association produces a self-study series for technicians
that covers five areas of pest control, management manuals, an encyclopedia of
struptural pest control, a number of specific subject matter technical reference
manuals, and a pamphlet series
Sheet Metal and
f Air Conditioning
L Contractors* National
r Association
t (SMACNA)
, r
HVAC Duct Construction Standards Metal and flexible (1985). Primarily for
commercial and institutional work, this set of construction standards is a collection
of material from earlier editions of SMACNA's low-pressure, high-pressure, flexible
duct, and duct liner standards. In addition, SMACNA has published a manual
"entitled Indoor Air Quality that contains basic information on many aspects of
indoor air quality and guidance on conducting building evaluations and indoor air
quality audits. Other related SMACNA publications include HVAC Duct Systems
Inspection Guide, HVAC Systems Testing, Adjusting and Balancing, and HVAC
Air Duct Leakage Test Manual,
Managing Buildings for Good IAQ 43
-------
Page Intentionally Blank
-------
Diagnosing IAQ Problems
1 he goal of the diagnostic building
investigation is to identify and solve the
indoor air quality complaint in a way that
prevents it from recurring and that does not
create other problems. This section
describes a method for discovering the
cause of the complaint and presents a
"toolbox" of diagnostic activities to assist
you in collecting information.
Just as a carpenter uses only the tools
that are needed for any given job, an IAQ
investigator should use only the investiga-
tive techniques that are needed. Many
indoor air quality complaints can be
resolved without using all of the diagnostic
tools described in this chapter. For
example, it may be easy to identify the
source of cooking odors that are annoying
nearby office workers and solve the
problem by controlling pressure relation-
ships (e.g., installing exhaust fans) in the
food preparation area. Similarly, most
mechanical or carpentry problems prob-
ably require only a few of the many tools
you have available and are easily accom-
plished with in-house expertise.
The use of in-house personnel builds
skills that will be helpful in minimizing
and resolving future problems. On the
other hand, some jobs may be best handled
by contractors who have specialized
knowledge and experience. In the same
way, diagnosing some indoor air quality
problems may require equipment and skills
that are complex and unfamiliar. Your
knowledge of your organization and
building operations will help in selecting
the right tools and deciding whether in-
house personnel or outside professionals
should be used in responding to the
specific IAQ problem.
Start (reason for concern)
Initial walkthrough
preparation
visual inspection
talk with occupants and staff
Do you have
an explanation
for the complaint ?
Collect additional
information about
building occupants
the HVAC system
pollutant pathways
pollutant sources
(sample contaminants if needed)
Develop one or more hypotheses
to explain the problem. Test by
manipulating building conditions
or exposure, or by performing
appropriate tests.
Do results
support your
hypothesis ?
FIGURE 6-1:
Conducting an IAQ Investigation
Note: Outside assistance may be needed at
any point in the Investigation, depending
upon the complexity of the problem, the skills
available in-house, time pressures, or other
factors.
Make necessary
changes so that
the problem will
not recur.
Diagnosing IAQ Problems 45
-------
The IAQ investigation
is often a repetitive
cycle of information-
gathering, hypothesis
formation, and
hypothesis testing.
OVERVIEW: CONDUCTING AN
IAQ INVESTIGATION
An IAQ investigation begins with one or
more reasons for concern, such as occu-
pant complaints. Some complaints can be
resolved very simply (e.g., by asking a few
common sense questions of occupants and
facility staff during the walkthrough). At
the other extreme, some problems could
require detailed testing by an experienced
IAQ professional. In this section "the
investigator" refers to in-house staff
responsible for conducting the IAQ
investigation.
The flowchart on page 45 shows that
the IAQ investigation is a cycle of infor-
mation-gathering, hypothesis formation,
and hypothesis testing. The goal of the
investigation is to understand the IAQ
problem well enough so that you can solve
it. Many IAQ problems have more than
one cause and may respond to (or require)
several corrective actions.
Initial Walkthrough
An initial walkthrough of the problem area
provides information about all four of the
basic factors influencing indoor air quality
(occupants, HVAC system, pollutant
pathways, and contaminant sources). The
initial walkthrough may provide enough
information to resolve the problem. At the
least, it will direct further investigation.
For example, if the complaint concerns an
odor from an easily identified source (e.g.,
cooking odors from a kitchen), you may
want to study pollutant pathways as a next
step, rather than interviewing occupants
about their patterns of discomfort.
Developing and Testing
Hypotheses
As you develop an understanding of how
the building functions, where pollutant
sources are located, and how pollutants
move within the building, you may think
of many "hypotheses," potential explana-
tions of the IAQ complaint. Building
occupants and operating staff are often a
good source of ideas about the causes of
the problem. For example, they can
describe changes in the building that may
have occurred shortly before the IAQ
problem was noticed (e.g., relocated
partitions, new furniture or equipment).
Hypothesis development is a process
of identifying and narrowing down
possibilities by comparing them with your
observations. Whenever a hypothesis
suggests itself, it is reasonable to pause
and consider it. Is the hypothesis
consistent with the facts collected so far?
You may be able to test your hypothesis
by modifying the HVAC system or
attempting to control the potential source
or pollutant pathway to see whether you
can relieve the symptoms or other condi-
tions in the building. If your hypothesis
successfully predicts the results of your
manipulations, then you may be ready to
take corrective action. Sometimes it is
difficult or impossible to manipulate the
factors you think are causing the IAQ
problem; in that case, you may be able to
test the hypothesis by trying to predict how
building conditions will change over time
(e.g., in response to extreme outdoor
temperatures).
Collecting Additional
Information
If your hypothesis does not seem to be a
good predictor of what is happening in the
building, you probably need to collect
more information about the occupants,
HVAC system, pollutant pathways, or
contaminant sources. Under some
circumstances, detailed or sophisticated
measurements of pollutant concentrations
or ventilation quantities may be required.
Outside assistance may be needed if
repeated efforts fail to produce a successful
hypothesis or if the information required
calls for instruments and procedures that
are not available in-house.
46 Section 6
-------
Results of the Investigation
Analysis of the information collected
during your IAQ investigation could
produce any of the following results:
The apparent caum(s) of the complaint(s)
is (are) Mentified.
Remedial action and follow-up evaluation
will confirm whether the hypothesis is
correct.
Other IAQ problems are identified that
are not related to the original complaints,
These problems (e.g., HVAC malfunc-
tions,, strong pollutant sources) should be
corrected when appropriate.
A better understanding of potential IAQ
problems is needed in order to develop a
plan for corrective action.
It may be necessary to collect more
detailed information and/or to expand the
scope of the investigation to include
building that were previously
overlooked. Outside assistance may be
needed.
The cause of the original complaint
cannot be identified,
A thorough investigation has found no
deficiencies in HVAC design or operation
or in the control of pollutant sources, and
there have been no further complaints. In
the absence of new complaints, the original
complaint may have been due to a single,
unrepeated event or to causes not directly
related to IAQ.
Using Outside Assistance
Some indoor air quality problems may be
difficult or impossible for in-house
investigators to resolve. Special skills or
instraments may be needed. Other factors
can also be important, such as the benefit
of having an impartial outside opinion or
the need to reduce potential liability from a
serious IAQ problem. You are best able to
make the judgment of when to bring in an
outside consultant. See Section 8 for a
discussion of hiring professional assistance
to solve an IAQ problem.
INITIAL WALKTHROUGH
An investigation may require one or many
visits to the complaint area. The amount
of preparatory work needed beforethe
initial walkthrough varies with the nature
and scope of the complaint and the
expertise of the investigator, among other
factors. For example, an in-house investi-
gator who is already familiar with the -
layout and mechanical system in the
building may begin responding to a
complaint about discomfort by going
directly to the complaint area to check the
thermostat setting and see whether air is
flowing from the supply outlets.
If the investigator is not familiar with
the building or is responding to complaints
that suggest a serious health problem, more
preparation may be needed before the
initial walkthrough. The activities listed
below can be directed at a localized
"problem area" or extended to include the
entire building:
Collect easily-available information about
the history of the building and the
complaints.
Identify known HVAC zones ami com-
plaint areas.
Begin to identify potential sources and
pollutants (e.g., special use areas near the
complaint location). Having a copy of
mechanical and floor plans can be helpful
at this stage, especially if they are
reasonably up-to-date.
Notify the building occupants of the
upcoming investigation.
TeE them what it means and what to
expect
Diagnosing IAQ Problems 47
-------
This improvised catch basin
Is Intended to collect water
seeping into the building
from below grade. Although
the catch basin "solves" the
problem of uncontrolled
water leakage, it also pro-
vides an indoor location
that could support the
growth of microbiologicals
and create IAQ problems.
Identify key individuals needed for access
and information.
A person familiar with the HVAC systems
in the building should be available to assist
the investigator at any time during the
onsite phase. Individuals who have
complained or who are in charge of
potential sources (e.g., housekeeping, non-
HVAC equipment) should be aware that
their information is important and should
be contacted for appointments or telephone
interviews if they will not be available
during the onsite visit
The initial walkthrough provides an
opportunity to question complainants about
the nature and timing of their symptoms
and to briefly examine the immediate area
of the complaint. The investigator
attempts to identify pollutant sources and
types and observes the condition and
layout of the HVAC system serving the
complaint area. Facility staff can be asked
to describe the operating schedule of
equipment. Obvious problems (e.g.,
blocked diffusers, malfunctioning air
handlers) can be corrected to see if the
complaints disappear. The walkthrough
can solve many routine IAQ problems and
will suggest directions for a more complex
investigation, should one be necessary.
Some investigators avoid taking any
measurements during the initial walk-
through so that they are not distracted from
"getting the big picture." Others find that
using smoke sticks, digital thermometers,
and direct reading CO2 meters or detector
tubes to take occasional measurements
helps them develop a feel for the building.
It may help to keep the following
questions in mind during the initial
walkthrough:
Are there obvious pollutant sources? Do
they appear to be adequately controlled?
Are pollutant indicators present, such as
odors, excessive dust, or staining?
Are there sanitation problems (e.g.,
debris near outdoor air intake, visible
mold growth, major water damage) that
could be introducing air contaminants?
Are there any conditions or activities
occurring in or near the building that
could be related in timing, location, and
health effects to the complaints?
Are there any deficiencies in the HVAC
system that serves the complaint area?
Does equipment serving the area (e.g.,
thermostats, diffusers, fans, dampers,
filters) appear to be operating, clean, and
in good condition?
Do operating procedures exist, and does
the staff foEow them?
Do records indicate that the system was
commissioned (set, tested, and balanced)
after construction?
Do records indicate that system compo-
nents are regularly inspected, calibrated,
and adjusted?
48 Section 6
-------
Are there pathways and pressure differ-
ences which could be moving contami-
nants into the complaint area from the
outdoors or from other parts of the
building?
COLLECTING ADDITIONAL
INFORMATION
Additional information will be needed if
the initial walkthrough does not identify
the cause of the problem. The following
pages present techniques for collecting
information about the occupant com-
plaints, HVAC system, pollutant pathways,
and pollutant sources and using that
information to develop a hypothesis that
could explain the problem. Common sense
will suggest the appropriate sequence of
steps during this part of the investigation.
For example, if the complaint is limited to
a single room, it makes sense to evaluate
pollutant pathways into that room before
attempting to inventory sources in loca-
tions outside of, but connected to, the
complaint area. On the other hand, if the
complaint involves a recognizable odor
(e.g., exhaust fames), it may be more
practical to begin by locating the potential
source(s) of the odor before trying to
identify pollutant pathways.
Forms and checklists such as the
samples provided in this document (modi-
fied if needed) can help investigators to
record information in an organized way.
Small copies of basic floor plans, such as
fire evacuation plans, are convenient for
noting locations of observations.
Any instruments that will be used
should be inspected to make sure they are
in working order and calibrated. IAQ,
investigations generally include the use of,
at a minimum: heatless chemical smoke
devices and instruments for measuring
temperature and humidity.
Carbon dioxide measuring devices
(detector tubes with a hand pump or a
direct reading meter) are helpful for most
investigations. Other instruments may be
needed as the investigation progresses.
See Appendix A for additional guidance on
common IAQ measurements.
Tools for Collecting Information
The following pages present strategies,
tools, and forms for the investigator to use
during an in-depth investigation. The
Incident Log shown below (and in Tab V)
can be used to track the course of an inves-
tigation from the receipt of the original
complaint.
Sample Form
Incident Log
File
Number
Date
Problem
Location
Investigation Record
(check the forms that were used)
Complaint
Form '.
Occupant
Interview
Occupant'
...v.'Dteiy' ..'.-'
//Log of
Activities
Zone/Room
Record
HVAC
Checklist
Pollutant
Pathway
Source ,
Inventory
Hypothesis
; . Form'/.;,
Outcome /
Comments
Log Entry By
(initials)
Diagnosing IAQ Problems
-------
\f\enf existing
i;tnfpjrrj|rt!oniflbo,L!
I'cgmpTaints
' .r-"1 ""4K1:!'. ' Wii*?, .-.::,
Collect additional
*-occupants
Existing Records
aint Form
An Initial walkthrough may
uncover problems such as
this unsanitary condition in
theHVAC system. Bird
droppings have collected in
an air supply plenum near
an outdoor air intake that
was not protected by a
birdscreen.
The discussion that follows has been
divided into categories of occupant data,
HVAC system data, pollutant pathway
data, and source data. However, the
suggestions for collecting and using
information reflect the interdependence of
these factors. For example, the operation
of the air distribution system affects
pollutant pathways, and the air distributior
system can also be a source of pollutants.
Indoor air quality related complaints
may develop from a variety of causes.
Neither the discussion of strategies for
collecting information nor the suggestions
for interpreting data can present the full
range of possible situations encountered in
buildings. They are intended to present a
problem-solving approach that can help
facility staff to understand and resolve
many common indoor air quality prob-
lems. If you decide to hire outside
professionals to resolve your IAQ com-
plaint, this discussion of strategies and
tools should help you to understand and
oversee their investigative work.
COLLECTING INFORMATION
ABOUT OCCUPANT
COMPLAINTS
Occupant data falls into two categories:
complaints of discomfort or other symp-
toms (e.g., teary eyes, chills) and percep-
tions of building conditions (e.g., odors,
draftiness). Investigators can gather
valuable information about potential
indoor air problems by listening to
occupants, and use that information for:
defining the complaint area within the
building
suggesting directions for farther investi-
gation, either by identifying other events
that seem to happen at the same time as
the incidents of symptoms or discomfort,
or by identifying possible causes for the
types of symptoms or discomfort that are
occurring
indicating potential measures to reduce
or eliminate the problem
Review Existing Records of
Complaints
If there is a record of occupant complaints,
a review of that record can help to define
the location of the IAQ problem and
identify people who should be interviewed
as part of the investigation. Information
about the history of complaints could also
stimulate theories about potential causes of
the problem.
Interview Occupants
The most obvious way to collect informa-
tion from building occupants is to talk to
50 Section 6
-------
them in person. If it is not possible to
interview everyone who has complained
about building conditions, the investigator
should attempt to interview a group of
individuals that reflects the concerns of the
affected areas.
The investigation may also include
occupant interviews with building
occupants who do not have complaints.
Then conditions in the complaint area can
be compared to conditions in similar
building locations where there are no
complaints.
A sample Occupant Interview form is
shown here (there is another copy in
Tab V). It can also be presented in a
written form in order to get information
from more people than can be interviewed.
The following key points will help
interviews to be productive:
Read the discussion of evaluating
occupant data before you conduct
interviews to be certain that you
understand what sort of information is
needed.
Make a copy of the interview form for
each person you speak with, and use the
form to record the answers to your
questions.
Choose a location in which the person
you are interviewing feels comfortable to
speak freely.
Explain that the interview is intended to
help discover and correct the cause of the
complaints. Encourage the person you
are interviewing to join in this coopera-
tive problem-solving effort.
Give the person you are interviewing
enough time to think about your ques-
tions.
If complainants are reluctant to answer
questions about health symptoms,
respect their desire for privacy. Planning
for how to maintain this privacy is
warranted, and in some cases may be
mandated.
Feel free to expand the interview by
adding questions that help to improve
-' Sample Form
I Occupant Interview
I ^SYMPTOM PATTERNS
.- What kind of symptoms or discomfort are you experiencing?
f~- -Are you aware of other people with similar symptoms or
'.- ^ concerns? Yes No
* V -
If so, what are their names and locations?
r Do you have any health conditions that may make you particularly
susceptible to environmental problems?
^7 TIMING PATTERNS
[ " When did your symptoms start?
your understanding or explore their
hypotheses (or your own) about what
may be causing the problem. Always be
open to answers that may not fit your
hypotheses.
You may sometimes need to clarify a
question by giving examples of the sort
of information you are interested in. Try
to provide more than one example so that
you don't seem to be telling the person
the answer you want. Be particularly
cautious about mentioning specific
health effects.
The Occupant Interview includes
many basic points that are found in
questionnaires used by professional IAQ
investigators. It is important to note,
however, that this form is not called a
"questionnaire." Formal questionnaires
may be useful for quantitative epidemiol-
ogy, IAQ research, complex IAQ investi-
gations, or when litigation is a possibility.
In these cases, questionnaires must be
carefully designed and executed by people
with an understanding of representative
sampling and expertise in public health,
industrial hygiene, or medicine. Use of
questionnaires for such purposes is beyond
the scope or expertise of most in-house
Diagnosing IAQ Problems 51
-------
,T,
งi Occupant Diary
- ...... , - ' --r r-T iซ,;--?i^ ,V!- -s , .....,
s On the form below, please record each occasion when you
ป'** ป It i:lt,L Ijllp* 'ซ ...... *M 'fc^l'II^IJIIta^,^^^ , w_ ซซ-,ปป ~ylUul-ll!ซซ ซซ ...... Mซwซa.'.uj ซ VNTT /uป l^ซ ^ ,u L Jm "lll
experience a symptom of ill-health or discomfort that you think
tff, ":-,l-:l-r',,' i ...... - ..................... i ...... rป ......... 1?-ป-"-V.,,. ;ป pmm, - ....... n-n, ..... -,_,,_ ........ ..... , ..... ..... .ฃ, ...... ..... ........ .,
f ,
: i.'HJuirjLiiU'iB! i In in 1 tin jib iilii):iiih!,:liiiiii 11 Jsii'iiorii - - . it'ff
'. lib ซ i.J'l! ' 1 i ill!'! I J , Iliiil ill! 1 liiiiilli!" iilMll J S ] - u 'iiA'i 1 li ll ilih'" , :
TinM/Date
Location
Symptom
Severity/Duration
Comments
Samplo Form'"
Log of Activities arid System Operation
On the form below, please record your observations of HVAC
system" operation, maintenance activities, and any other
illll1-11111 ...... " " '
^111^11^ ...... i K "ido n"f Jfyng Q cause
ป of IAQ complaints in this building. Please report any other
5 observations (e.g., weather, other associated events) that you think
; may be important as welK
Equipment and activities of particular interest:
Air Handler(s): ......
Exhaust Fan(s): _____^^_r^_r^^_^^_
Other Equipment or Activities:
Date/Tim*
Day of Week
Equipment Item/Activity
Comments
investigations; if such questionnaire data is
needed, building owners and managers
should use professionals.
Ask Occupants and Facility
Staff to Keep More Detailed
Records
Many events occur simultaneously in and
around a complex building, and it can be
very difficult to judge which of those
events might be related to the IAQ
complaints. In trying to resolve stubborn
problems, professional investigators
sometimes ask occupants and facility staff
to keep day-by-day records. Occupants are
asked to record the date and time of
symptoms, where they are when the
symptoms appear, and any other informa-
tion that might be useful. Such informa-
tion could include observations about the
severity and duration of symptoms and
comments on weather conditions, events,
and activities that are happening at the
same time. Facility staff are asked to
record the date and time of events such as
maintenance work, equipment cycles, or
deliveries. If symptoms seem to occur at
particular times of day, staff can focus
their attentions on recording events that
occur before and during those periods.
Such records are likely to produce more
accurate and detailed information than can
be obtained by relying on memory. (Use
the Occupant Diary and the Log of
Activities and System Operation shown
here and included in Tab V.)
52 Section 6
-------
USING THE OCCUPANT DATA
The pattern of complaints within the
building helps to define the complaint area.
The timing of symptoms and the types of
symptoms reported may provide clues
about the cause of the problem.
Strategies for Using Occupant Data
m Define the complaint area
Look for timing patterns :
Look for symptom patterns
Exhaust fumes are drawn
into this building's outdoor
air intake when trucks are
idling at the nearby loading
dock. Tools such as the
Occupant Diary and Log of
Activities and System
Operation can help to
identify intermittent
pollutant sources such as
this one.
Diagnosing IAQ Problems 53
-------
SUGGESTIONS
A Widespread, no apparent
1 spatial pattern
V-
Check ventilation and tem-
perature control for enf|re_
building. "^ ^"^^
outdoor air quality.
that are t
out building
^iaง*f(e.gl, cleaning materials),
. ^Consider explanations other
'"""^iJian air contaminants.
WM i>jw ^ r .(up y^^" " ||
u ___
B".g,ป affecting
lndMauaI>|gojr|is<; zones, or
*"*"'''*
CKecKventiiaticJn and tem-
perature control wjthin the "_
complaint"area. "
iL|p ^t/ii.Review polluta_ntsources
''"^USt-l .WilW|j*'''' affecting the complaint" area.'
*'- ^^^'\^m^''^"!A^^'lY,C^^^m^^'m3famM
may be
i , ซ, - as sources or distribu-
**^-;ii'-1 to^s'gf pollutants.
radiant heat
(gan or loss),_and other
local^d je'mperaUire control
or ven^!a|J9*n problems near
the affectpd |pdiyiduaHs),
Review local pollutant
source(s) near the affected
', Ipdividual{s).
Consider that common : ..
* background sources may
affect only susceptible
'" '
','.*' ,t,W'.fc,AT
"^irff
' Cojisjder the possibility that
have
-------
Look for Timing Patterns
Look for patterns in the timing of com-
plaints. The timing of symptoms and
complaints can indicate potential causes
for the complaints and provide directions
for farther investigation. Review the data
for cyclic patterns of symptoms (e.g.,
worst during periods of minimum ventila-
tion or when specific sources are most
active) that may be related to ETVAC
system operation or to other activities in
and around the building.
1MING PATTERNS
SUGGESTIONS
.ymptoms begin and/or
taJMHoecupiect period "
j js.**^. ซ&
^- " , - ,
t , *"v
<^r<-'-.. -i , .
s^ifeWi"^ ~ ซ^~ * ->^ *,
m Review HVAC operating ;
cycles. Emissions from
" ฅuildTng~ materials, or from the \
Ti HyAC fystern itself, may build i
. .up during unoccupied periods.
^ymptoms worsen over
J cguj-se of occupied period
^^jrt^:; - -. - ,; -,
v.wy* -f" >. ^. f.,
\ Consider that ventilation may
not be adequate to handle
activities or equipment
""TwithjrTthe 'buildfngT
termittent symptoms
Look for daily, weekly, or
j,,, seasonal cycles or weather-
.'' ;freta|ed "patterns, "and check
_", 'linkage to other events in and
4if"t^fff, 5*^SSBi?^7; | -^ ~. .-j t.
* i. .ซi,,n,i *ป|e buildma.
- ."ซ-" r ซ-- -T. -,-
aingie event of symptoms
. i.
Consider spills, other
" >, unredeated events as sources,
t' ''*.i-
,,, . , ,
ecent onset of symptoms
ZZ^'
m A^k sSRnd dccupanteW "^
K ^''describe recent changesor
-*^v=i*^ Av*^,* '^^'^ ^ vf^'-r-^ ' -
;t ^e,yentsje,.0., remodeling,
ปi^c Wnoyafiori^ redecorating,
. t flVAlifs^tem adjustments^
;, or spills}. "
Symptoms relieved on leaving
ie building, either immedi-
tely, overnight, or (In some
ases) after extended periods
j a way from the building
Consider that the problem is
likely to be building-related,
though not necessarily due to
air cjuality. Other stressors
(e.g., lighting, noise) may be
-*"x involved.
. .r. ^ .-* uป "... . '.''.'
Symptoms never relieved,
|evep after extended absence
^frorn building (e.g., vacations)
, , ^~ - F- f"^f ' *ปป-4ซyf
Consider that the problem
may not be building-related.
- -
Diagnosing IAQ Problems 55
-------
The following chart lists
some common symptom
groups that can be related
to Indoor air quality, along
with possible sources or
causes of those symptoms.
Building managers are
cautioned that this is only a
partial listing,
Look for Symptom Patterns
Look for patterns in the types of symptoms
or discomfort. IAQ investigations often
fail to prove that any particular pollutant
or group of pollutants are the cause of the
problem. Such causal relationships are
extremely difficult to establish. There is
little information available about the health
effects of many chemicals. Typical indoor
levels are much lower than the levels at
which toxicology has found specific
effects. Therefore, it may be more useful
to look for patterns of symptoms than
for specific pollutant and health effect
relationships.
Investigators who are not medically
trained cannot make a diagnosis and should
not attempt to interpret medical records.
Also, confidentiality of medical informa-
tion is protected by law in some jurisdic-
tions and is a prudent practice everywhere.
SYMPTOM PATTERNS
SUGGESTIONS
THERMAL DISCOMFORT Check HVAC condition and operation.
Measure indoor and outdoor temperature and humidity (see Figure 6-2 on
the opposite page). See if extreme conditions exceed design capacity of
HVAC equipment.
Check for drafts and stagnant areas.
Check for excessive radiant heat gain or loss.
COMMON SYMPTOM GROUPS
Headache, lethargy, nausea. If onset was acute (sudden and/or severe), arrange for medical evaluation,
drowsiness, dizziness as the problem may be carbon monoxide poisoning.
Check combustion sources for uncontrolled emissions or spillage. Check
outdoor air intakes for nearby sources of combustion fumes,
Consider evacuation/medical evaluation if problem isn't corrected quickly.
Consider other pollutant sources.
Check overall ventilation; see if areas of poor ventilation coincide with
complaints.
Congestion; swelling, itching or
irritation of eyes, nose, or
throat; dry throat; may be
accompanied by non-specific
symptoms (e.g. headache,
fatigue, nausea)
May be allergic, if only small number affected; more likely to be irritational
response if large number are affected.
Urge medical attention for allergies.
Check for dust or gross microbial contamination due to sanitation
problems, water damage, or contaminated ventilation system.
Check outdoor allergen levels (e.g., pollen counts).
Check closely for sources of irritating chemicals such as formaldehyde or
those found in some solvents.
Cough; shortness of breath;
fever, chills and/or fatigue after
return to the building
Diagnosed infection
Suspected cluster of rare or
serious health problems such
as cancer, miscarriages
May be hypersensitivity pneumonitis or humidifier fever. A medical
evaluation can help identify possible causes.
Check for gross microbial contamination due to sanitation problems, water
damage, or contaminated HVAC system.
May be Legionnaire's disease or histoplasmosis, related to bacteria or fungi
found in the environment.
Contact your local or State Health Department for guidance.
Contact your local or State Health Department for guidance.
OTHER STRESSORS
Discomfort and/or health
complaints that cannot be
readily ascribed to air contami-
nants or thermal conditions
Check for problems with environmental, ergonomic, and job-related
psychosocial stressors.
56 Section 6
-------
Figure 6-2 shows the range of tempera-
tures and relative humidities that fall
within the comfort zone for most individu-
als dressed in "typical" clothing and
involved in light, mostly sedentary
activity. Recent research suggests that
indoor air quality is judged to be worse as
temperatures rise above 76ฐF, regardless of
the actual air quality.
There is considerable debate among
researchers, IAQ professionals, and health
professionals concerning recommended
levels of relative humidity. In general, the
range of humidity levels recommended by
different organizations seems to be 30% to
60% RH. Relative humidities below this
level may produce discomfort from
dryness. On the other hand, maintaining
relative humidities at the lowest possible
level helps to restrict the growth of mold
and mildew. The concerns (comfort for
the most part) associated with dry air must
be balanced against the risks (enhanced
microbiological growth) associated with .
humidification. If temperatures are
maintained at the lower end of the comfort
range (68 - 70ฐF) during heating periods,
relative humidity in most climates will not
fall much below 30% (also within the
comfort range) in occupied buildings.
COLLECTING INFORMATION
ABOUT THE HVAC SYSTEM
IAQ complaints often arise because the
quantity or distribution of outdoor air is
inadequate to serve the ventilation needs of
building occupants. Problems may also be
traced to air distribution systems that are
introducing outdoor contaminants or
transporting pollutants within the building.
The investigation should begin with the
components of the HVAC system(s) that
serve the complaint area and surrounding
rooms, but may need to expand if connec-
tions to other areas are discovered. Your
goal is to understand the design and
operation of the HVAC system well
jy RGURE 6-2: Acceptable Ranges of Temperature and Relative
:^ Humidity During Summer and Winter1
I-
*?'
1
ปw
..Relative Humidity
:T , 30%
c.~ 40%
iT-"-- 50%2
ซ;f ; 60%
Winter Temperature
68.5ฐF - 76,0ฐF
68.5ฐF-75JฐF
68.5ฐF-74.5ฐF
68.0ฐF-74.0ฐF
Summer Temperature
74.0ฐF - 80.0ฐF
73.BฐF-79.5ฐF
73.0QF-79.0ฐF
72.5ฐF-78.0DF
IT:-Ir ' - - - '
ggป' Applies for persons clothed in typical summer and winter clothing, at light,
. mainly sedentary activity.
?'- *. ->.'
*|iJiPURCE: Adapted from ASHRAE Standard 55-1981, Thermal Envtronmen-
Hjjfa/ Conditions for Human Occupancy
enough to answer the following questions:
Are the components that serve the
immediate complaint area functioning
properly?
Is the HVAC system adequate for the
current use of the building?
* Are there ventilation (or thermal com-
fort) deficiencies?
Should the definition of the complaint
area be expanded based upon the HVAC
layout and operating characteristics?
An evaluation of the HVAC system
may include limited measurements of
temperature, humidity, air flow, and CO2,
as well as smoke tube observations.
Complex investigations may require more
extensive or sophisticated measurements of
the same variables (e.g., repeated CO2
measurements taken at the same location
under different operating conditions,
continuous temperature and relative
humidity measurements recorded with a
data logger). A detailed engineering study
may be needed if the investigation discov-
ers problems such as the following:
ซ airflows are low
HVAC controls are not working or are
working according to inappropriate
strategies
building operators do not understand (or
are unfamiliar with) the HVAC system
WHAT DO YOU
KNOW SO FAR?
Use,the Hypothesis
"'-. Form on page 223 to
make brief notes after
reviewing the occupant
data. .:"-.-". : '- '
Decide whether you ,
have a hypothesis that
might explain the
complaints, if so, test
it. (See page 78 for a
discussion of
hypothesis testing.)
Decide what else you
, need to know,
Consider whether
In-house expertise is
sufficient or outside
assistance is needed.
(See Section 8 for
guidance on hiring
outside assistance.)
Diagnosing IAQ Problems 57
-------
COLLECTING HVAC SYSTEM INFORMATION
Strategies Tools
Review existing docu-
mentation on HVAC
design, installation, and
operation
Collect:
design documents, testing and
balancing reports
operating instructions, control
manufacturer's installation data
Talk to facilities staff
Ask facilities staff to record thejr
observations of equipment cycles,
weather conditions, and other events
using Log of Activities and System
Operations
Inspect system layout,
condition, and operation
Use additional instru-
ments as appropriate
Use:
Zone/Room Record
HVAC Checklist - Short Form and/or
HVAC Checklist - Long Form
thermometer and sling psychrom-
eter (or electronic equivalent) to
measure temperature and humidity
micromanometer (or equivalent) to
measure pressure differentials
ป 0-2" and 0-10ฐ water gauge (w.g.)
to measure at fans and intakes
* 0-.25" w.g. with pitot tube to check
airflow in ducts
chemical smoke for observing
airflow patterns
a device to assess airflow from
diffusers
rough quantitative; anemometer;
velometer
* accurate quantitative: flow hood
carbon dioxide measurement
devices
* detector tubes with a hand pump
direct reading meter
Instruments often used by profes-
sional lAQ consultants include:
a hygrothermograph to log tempera-
ture and humidity
tracer gas and measurement
equipment
a device to measure airborne
participates
measurement devices for carbon
monoxide and other contaminants
of interest
Review Documentation on
HVAC Design, Installation, and
Operation
A review of existing documentation (e.g.,
plans, specifications, testing and balancing
reports) should provide information about
the original design and later modifications,
particularly:
the type of HVAC system (e.g., constant
volume, VAV)
locations and capacities of HVAC
equipment serving the complaint area
the planned use of each building area
supply, return, and exhaust air quantities
location of the outdoor air intake and of
the supply, return, and exhaust registers,
diffusers, and grilles that serve the
complaint area
The most useful way to record this
information is to make a floor plan of the
complaint area and surrounding rooms.
You may be able to copy an existing floor
plan from architectural or mechanical
drawings, fire evacuation plans, or some
other source.
If there is no documentation on the
mechanical system design, much more on-
site inspection will be required to under-
stand the HVAC system. The HVAC
system may have been installed or
modified without being commissioned,
so that it may never have performed
according to design. In such cases, good
observations of airflow and pressure
differentials are essential. In addition, load
analyses may be required,
Talk to Facility Staff
Facility staff can provide important current
information about equipment operating and
maintenance schedules and breakdowns or
other incidents. There may be inspection
reports or other written records available
for review. Staff members who are
familiar with building systems in general
and with the specific features of the
58 Section 6
-------
building under investigation can be very
helpful in identifying conditions that may
explain the indoor air quality complaints.
Some facility operators have extensive
preventive maintenance programs. On the
other hand, discussion could reveal that
facility staff are not operating the building
according to its design, because:
they do not understand the design logic
of the HVAC system
they have been asked to run the HVAC
system at the lowest possible energy cost
they do not have the manpower to
operate the building properly
the HVAC system has not been modified
to accommodate changes in the use of
space or increases in the occupant
population
Staff may have noticed occupant
activities that are indicators of inadequate
ventilation or poorly controlled tempera-
tures, such as:
desktop fans, heaters, or humidifiers
supply diffusers blocked off with tape or
cardboard
popped-up ceiling tiles
interference with thermostat settings
IAQ complaints are often intermittent.
Discussions with staff may reveal patterns
that relate the timing of complaints to the
cycles of equipment operation or to other
events in the building such as painting,
installation of new carpeting, or pest
control. These patterns are not necessarily
obvious. Keeping a day-to-day record may
help to clarify subtle relationships between
occupant symptoms, equipment operation,
and activities in and around the building.
(See Occupant Diary and Log of
Activities and System Operations on
page 52 and in Tab V.) Staff members
may have theories about the cause of
the problem.
Inspect System Layout,
Condition, and Operation
If the building is new or if there is a pre-
ventive maintenance program with recent
Above: An investigation of this building
revealed no problems with the HVAC
system, although the amount of outdoor
air was very low. In a more thorough
inspection of the HVAC system, investi-
gators found that the wiring to this out-
door air damper motor had never been
connected. No outdoor air was entering
the building through the intake controlled
by this damper. Below: These investiga-
tors are examining a perimeter fan-coil
unit. Self-contained heating or cooling
units such as this one are often over-
looked during routine maintenance.
There may be many such units in a single
building, sometimes in remote or inac-
cessible locations.
Diagnosing IAQ Problems 59
-------
The design specifications
for this building called for a
minimum 20% setting on
the outdoor air damper
control. Facility staff low-
ered the minimum outdoor
air setting to 10% in order
to save energy and reduce
operating costs. As a re-
sult, the building was
underventilated whenever
outdoor temperatures were
either very hot or very cold.
test and balance reports, it is possible (but
not necessarily likely) that the HVAC
system is functioning according to its
original design. Otherwise it is probable
that one or more features of building usage
or system operation have changed in ways
that could affect indoor air quality.
Elements of the on-site investigation
can include (but are not limited to) the
following:
Check temperature and/or humidity to see
whether the complaint area is in the com-
fort range.
Take more than one measurement to ac-
count for variability over time and from
place to place. Compare to Figure 6-2 on
page 57 (see also Appendix B).
Check thermostat operation.
Check whether the supply air tempera-
ture corresponds to the design criteria.
Use a hygrothermograph (if available) to
log temperature and humidity changes in
the complaint area.
Check for indicators of inadequate
ventilation.
Check supply diffusers to see if air is
moving (using chemical smoke). If it is
not, confirm that the fan system is operat-
ing, and then look for closed dampers,
clogged filters, or signs of leaks.
Compare design ah- quantities (if avail-
able) to building codes for the current
occupancy or ventilation guidelines (e.g.,
ASHRAE 62-19Z9, see Appendix B). If
the HVAC system, performing as de-
signed, would not provide enough venti-
lation air for current needs, then there is
good reason to believe that actual ventila-
tion rates are inadequate.
Measure carbon dioxide (CO2) in the
complaint area to see whether it indicates
ventilation problems. (See Appendix A
for a discussion of techniques for measur-
ing and interpreting CO2 concentrations.)
Measure air quantities supplied to and
exhausted from the complaint area, in-
cluding calculation of outdoor air quanti-
ties (see Appendix A for further guid-
ance). Be aware of damper settings and
equipment cycles when you are measur-
ing (e.g., are you evaluating minimum
outdoor air, "normal" conditions, or
maximum airflow?). Note that evalua-
tion of variable air volume (VAV) sys-
tems requires considerable expertise.
Compare the measured air quantities to
your mechanical system design specifica-
tions and applicable building codes. Also
compare ventilation rates to ASHRAE
62-1989. Some of the ventilation recom-
mendations of ASHRAE 62-1989 are
reproduced in Appendix B.
Check that equipment serving the com-
plaint area (e.g., grilles, diffusers, fans) is
operating properly.
Confirm the accuracy of reported operat-
ing schedules and controls sequences; for
example, power outages may have dis-
rupted time clocks, fans reported as
"always running" may have been acci-
dentally switched off, and controls can be
in need of calibration.
60 Section 6
-------
Check to see that equipment is properly
installed. For example, look for shipping
screws that were never removed or fans
that were reversed during installation, so
that they move air in the wrong direc-
tion.
Compare the current system to the
original design,
Check to see that all equipment called
for in the original design was actually
installed.
See whether original equipment may
have been replaced by a different model
(i.e., a model with less capacity or differ-
ent operating characteristics).
See whether the layout of air supplies,
returns, and exhausts promotes efficient
air distribution to all occupants and
isolates or dilutes contaminants.
(See Appendix A for guidance on using
chemical smoke to study airflow and mix-
ing patterns and CO2 to help determine the
adequacy of ventilation.)
If supplies and returns are close together,
heatless chemical smoke can be used to
check for short-circuiting (supply air that
does not mix properly with air in the
breathing zone, but moves directly to the
return grille). CO2 can also be used to
evaluate air mixing.
Use heatless chemical smoke to observe
airflow patterns within the complaint
area and between the complaint area and
surrounding spaces, including outdoors.
Compare airflow directions under vari-
ous operating conditions.
If the system layout includes ceiling
plenums, look above the ceiling for inter-
ruptions such as walls or full-height
partitions.
Consider whether the HVAC system itself
may be a source of contaminants.
Check for deterioration or unsanitary
conditions (e.g., corrosion, water damage
or standing water, mold growth or exces-
sive dust in ductwork, debris or damaged
building materials in ceiling plenums).
If the mechanical room serves as a mix-
ing plenum (i.e., return and outdoor air
are drawn through the room into the air
handler), check very carefully for poten-
tial contaminants such as stored solvents
and deteriorated insulation.
Use the forms provided in this document
to inspect the HVAC system.
Use the Zone/Room Record to describe
the ventilation system serving the com-
plaint area and surrounding rooms or
zones. The Zone/Room Record is
reproduced on page 62 and in Tab V.
Use the HVAC Checklist (short and/or
long form) to evaluate the condition of
HVAC system components that affect air
distribution and IAQ in the complaint
area. A portion of the HVAC Checklist-
Short Form is reproduced on page 62.
The HVAC Checklist - Long Form is
useful for more detailed examination of
the system. Complete copies of both
forms can be found in Tab V.
The dark streaks at the
outlet of this supply diffuser
could indicate a filtration
problem. Poorly maintained
or improperly sized filters
can allow dirt to be distrib-
uted through the building.
Diagnosing IAQ Problems 61
-------
_ , . .. ..
p"P^V Oml -VJPT.r- - ' S'ซ ;-*
MjMffRoom Record _ >...ป ป- *. -.
Ifus form Is to be used differently; dfDendmg on whetherthe, goal is to prevent or diagnose IAQ problems.
tqring developmjant of a profile, this form should be used to record more general information about the entire
Aiding,* during an Investigation, the form should lie used to record more detailed informatiQn ,งbout the
pmpfaJnt area and areas surrounding the complaint area or connected to it by pathways,
k , --= *, -J#ซ
1
1
: PROFIIi AND DIAGNOSIS INFORMAflON'
BuHdlng Area
tZotW/Room}
f"
Lffid^^
Source of
Outdoor Mr*
;,-* ^riTS-rt ....."-' -^ ^JT
it - *Sf*ป **ป - "
-------
.HEALTH AND SAFETY CONSIDERATIONS FOR
IAQ INVESTIGATORS
Normal safety precautions observedf during routine operation of the building
Joust be followed closely during IAQ inspections. When the (AQ investigator is
Jrfof familiar with the mechanical equipment in that particular facility, an operator
r engineer should be present at all times in equipment areas. Potential safety
iazards include:
"electrocution ,
^Injury from contacting fans, belts, dampers "or slamming doors
ip)jurn.s from steam or hot water lines -..,,.
alls in ventilation shafts or from ladders or roofs ,,-^
Investigators evaluating building IAQ generally do not encounter situations in
Jiich specific personal protection measures (e.g., protective garments and
respirators) are required. However, safety shoes antTeVeglasses are generally"
scommended for working around mechanical equipment. When severe con-
taiujnatiqn is present (e.g., microbiological, chemical, or asbestos), IAQ investi-
gators may need additional protection in the vicinity of certain building areas or'
puipment. Such decisions are site-specific and should be made in consultation*
i an experienced industrial hygienist. General considerations include the
following:
">; ; ^" , r~ ~%
Jlicrobiological: Care must be taken when serious building-related illness
fe.g,, Legionnaire's disease) is under investigation or When extensive micro&io-
logical growth has occurred. Investigators with allergy problems should be
^especially cautious. The array of potential contaminants makes ft difficult to
"know what sort of personal protection will be effective. At a minimum, investiga-
jtors should minimize their exposure to air in the interior of ducts or other HVAC
juipment unless respiratory protection is used. If there is reason to suspect
Biological contamination (e.g., visible mold growth), expert advice should be
ined about the kind of respiratory protection to use and how to use it
^Possible protective measures against severe microbiological contamination
iclude disposable coveralls and properly fitted respirators.
I
-3
hemical: Where severe chemical contamination is suspected, specific precau-
tions must be followed if OSHA action levels are approached. Such instances
rely occur in IAQ investigations. One possible exception might be a pesticide
"pill in a confined space. In this case, an appropriate respirator and disposable
jSgVeralls may be needed. ,
sbestos: An IAQ investigation often includes inspection above accessible
silings, inside shafts, and around mechanical equipment. Where material
^Suspected of containing asbestos is not only present, but also has deposited
?loose debris, the investigator should take appropriate precautions. This might
^include disposable coveralls and a properly fitted respirator. "
WJ3t-JMซ. <* i ? e y s> * * w x" i H *** '*rif i *""* -^" ** * "ป*" a
^ *1*j!'S
fftofe: The requirements for proper fit, physical condition of the wearer, and other 4
^considerations involved in selection of the proper respirator must be evaluated by an
Occupational safety and health specialist. There is a NIOSH Respirator Decision Logic for ' ^
fproper respirator selection, and OSHA has regulations for an appropriate respirator <
VSteotion program. " J
-... _ ,_.-_ *,"__- - ." .'.^^ -^uJJ
When the IAQ investi-
gator is not familiar
with the mechanical
equipment in that
particular facility, an
operator or engineer
should be present at
all times in equipment
areas.
Diagnosing IAQ Problems 63
-------
ALL SYSTEMS
;. Ventilation and
~tซmperature
control zones
Changes in
nquipmant
Operating
cycles
SUGGESTIONS
i Revise definition of complaint area
{if needed) to add spaces linked to
the original complaint area by
ductwork or controls.
i Check to see that thermostats
are properly located and function
properly.
Note equipment changes that
could be affecting the system's
performance (e.g., removal or
addition of equipment, replacement
by a different model).
i Review operating procedures for
occupied and unoccupied periods.
i Compare timing of occupied/
unoccupied periods to equipment
cycles and occupant complaints.
Confirm that time clocks are
reading the actual time. See
ASHRAE 62-1989 for suggested lead
times to allow proper flushing
before occupants arrive. In some
cases (e.g., warm, humid climates),
fans may need to operate during
unoccupied periods to prevent
mold growth or other problems.
Compare the Original Design to
the Current HVAC System
Consider the original HVAC design and
compare it to the current equipment,
layout, and controls. A variety of HVAC
system designs have been used in public
and commercial buildings. The type of
system used in your building affects the
control of ventilation air quantities and
distribution, as well as thermal comfort.
See Appendix B for a discussion of HVAC
system types.
64 Sections
-------
Use HVAC Data to Evaluate
Mitigation Measures
As you use the HVAC data to evaluate
potential mitigation measures, review the
suggestions made in both the box on the
facing page for all HVAC systems and in
the box on this page for the type of HVAC
system in your building.
SYSTEM TYPES
SUGGESTIONS
-: - No mechanical
<: ventilation or
-Tiexhaustonly
r -" Room units
p (e,g., unit
ventilators)
Constant
volume
f~~ Variable
Jl air volume
(VAV)
Identify the source(s) of ventilation
air (e.g., operable windows, doors
propped open).
Check whether the location of open
windows, doors, or other openings
'promotes the introduction of odors
or contaminants.
Check whether outdoor air intakes
are obstructed. Does their location
promote the introduction of odors
or contaminants?
i Note design airflows in the
complaint area (outdoor air, supply,
return, and exhaust) and surround-
ing spaces; compare to ASHRAE
62-1989 and to actual measured
airflows.
Note design airflows in the
complaint area (outdoor air, supply,
return, and exhaust) and surround-
ing spaces; compare to applicable
building codes, ASHRAE 62-1989,
- and to actual measured airflows.
Check whether outdoor air intakes
are obstructed. Does their location
promote the introduction of odors
. or contaminants? Check for
unsanitary conditions.
Check outdoor air damper controls.
In addition to all suggestions made
for constant volume systems:
Confirm whether the system design
allows regulation of outdoor air
quantities. Do VAV boxes have
stops to ensure that minimum
- amounts of outdoor air are deliv-
ered at all times during occupied
periods? Are the system controls
providing a constant ventilation rate
per person regardless of total sys-
tem airflows?
Observe.changes (if any) in airflow
patterns within and around the
" complaint area as the VAV system
throttles from maximum to
minimum flow.
Diagnosing IAQ Problems 65
-------
ROOM USE CHANGES SUGGESTIONS
Increased occupant
density
Change in type of
occupant population
Additional non-HVAC
equipment
Conversion to or addi-
tion of special uses
Compare temperature and humidity
tocpmfpitzone in ASHRAE 55-1981
guidejines.
Compare minimum outdoor air
" quantities to the original design,
applicable building codes, and
- ASHRAE 62-1989 guidelines.
Example: Introduction of a more
physically active group of occupants
can change thermal comfort require-
ments.
Compare temperature and humidity
to comfort zone in ASHRAE 55-1981
_ guidelines.
Compare minimum outdoor air
quantities to the original design,
applicable building codes, and
AgHjRAE 62-1989 guidelines.
Cneekjfor low-level contaminant
sources.
i Compare temperature and humidity
to comfort zone in ASHRAE 55-1981
ines.
i Consider the need for local exhaust
at point sources of contaminants.
Example: Modifications that convert
or add such special uses as smoking
lounges, print shops, or kitchen
facilities may also require changes in
the operation of the HVAC system.
Check pressure relationships
between special use areas and
surrounding spaces.
Consider the need for local exhaust
at point sources of contaminants.
Rearrangement of work
stations (e.g., relocation
of partitions)
Check that thermostats are properly
located. Compare temperature and
humidity to comfort zone in
ASHRAJE 55-1981 guidelines.
Check layout of supplies, returns,
and exhausts.
Checkfto make sure that partitions
do not block proper air circulation.
Compare the Original Uses of
Space to Current Uses
Compare the original uses of the complaint
area and surrounding rooms to current
uses of those areas. Indoor air quality
problems often arise when the usage of
rooms changes without corresponding
adjustments to the HVAC system. For
example, if ventilation appears to be a
problem despite a properly functioning
HVAC system, the existing system may
be inadequate to meet current needs.
66 Section 6
-------
Consider the Condition of the
HVAC System
Consider whether the HVAC system is
reasonably clean and functioning properly,
Review the results of the onsite inspection.
If you identified sanitary or operating
problems in the HVAC system serving the
complaint area, you may want to correct
those problems and see whether the
complaints are resolved before continuing
with the investigation.
K Unsanitary conditions
Moisture or standing water
STEM CONDITIONS
SUGGESTIONS
>ust and/or mold growth
i,Correct sanitary problems and
adopt necessary measures to
prevent recurrence of prob-
lems.
malfunctions
i Equipment breakdown
Jr* Obstructed diffusers or grilles
ฃ * Air distribution or mixing *
J^Tproblems: (e,.g,,equipment is
of balance, requires
n, or needs other.,. *
Maladjustment) ,
ฃ Air bypasses filters (due to
yj- * loose filter tracks, incorrect filter
pr "^"slze, or filter overloaded with
, . ... ,".. ~,-^,
! Air distribution system leaks
Pte (e.g., leaky ductwork; unin-
"ttended openings in pressurized
ceilings or in return air plenums),
asfe-^li!; * f ~v' ' i -* "* ^^?^ ^-
Evaluate whether the HVAC
defect could have caused the
IAQ complaint.
Correct the malfunctton(s),
and see whether complaints
are resolved.
Review maintenance program
and revise as needed to
prevent future problems.
HVAC functions properly.
However, there is evidence of
fc"' un derventif atio n.
Consider what adjustments
could be made to increase the
supply of outdoor air (or
decrease the ventilation
demand} In the complaint
area."
W AT" DO YOU
Use the Hypothesis,
'.Forni on page 223 to
rrtake brief notes,
: after reviewing the
v HVAC data.
pfecicle whether you
have a hypothesis
that might explain
trie complaints. If
so, test it. (See page
,78 for a discussion
of hypothesis
: testing.) *
Decide what else
you ne ed to know,
Consider whether in-
house expertise is
sufficient or outside
assistance Is needed.
(See Section 8. for
guidance ori hiring
: outside assistance.);
Diagnosing IAQ Problems 67
-------
COLLECTING INFORMATION
ABOUT POLLUTANT PATHWAYS
AND DRIVING FORCES
Unless the IAQ problem is caused by an
obvious contaminant located in the
complainant's immediate workspace, you
will need to understand the patterns of
airflow into and within the complaint area.
Correction of IAQ problems often involves
controlling pollutant movement through
sealing of pollutant pathways or manipula-
tion of the pressure relationships.
If the complaints being investigated are
limited to a few areas of the building, pollut-
ant pathways can be evaluated so that the
complaint area is properly defined before
conducting the source inventory. If com-
plaints are spread throughout the building,
COLLECTING PATHWAY INFORMATION
Strategies Tools
Identify pollutant
pathways
i Architectural and mechanical
drawings
i Pollutant Pathway Form for Investigations
i Sketch plan of complaint area
Observe direction
of air movement
Testing and balancing reports
Chemical smoke tests
Micromanometer or equivalent
evaluation of pathways could be a very
time-consuming process, and it may be
more practical to look for major contami-
nant sources before trying to discover how
the contaminants move within the building.
Identify Pollutant Pathways
Architectural and mechanical pathways
allow pollutants to enter the complaint area
from surrounding spaces, including the
outdoors. An examination of architectural
and mechanical plans can help in develop-
ing a list of connections to surrounding
areas. These include:
doors
operable windows
stairways
elevator shafts
utility chases
ductwork and plenums
areas served by common HVAC controls
(e.g., shared thermostats)
Onsite inspection is needed to confirm
the existence of these connections and to
identify other openings (e.g., accidental
openings such as cracks and holes). Fire
codes usually require that chases and hid-
den openings be firestopped. Check for the
existence and condition of firestops in
chases, especially those that connect both
vertically and horizontally.
Chemical smoke is being
used to detect the direction
and amount of airflow
through this closed
doorway. A building
Investigator must know
how the ventilation in the
building is designed to
operate in order to decide
whether the observed flow
of smoke is appropriate.
68 Section 6
-------
The Pollutant Pathway Form for
Investigations shown to the right can be
used along with a sketch plan of the
complaint area (similar to the example on
page 70) to record pathways and directions
of pollutant movement. A blank copy of
the form is included in Tab V.
Observe Air Movement
Direction
The airflow quantities shown in mechani-
cal plans or in testing and balancing
reports can be used to determine the
direction of air movement intended by the
designer. Onsite examination is necessary
to determine the actual direction of airflow
at each available pathway.
Chemical smoke tubes can be used to
determine airflow directions between the
complaint area and surrounding spaces
(including the outdoors), and to reveal air
circulation patterns within the complaint
area. A micromanometer (or equivalent)
can measure the magnitude of pressure
differences between these areas. The
sketch plan and the Pollutant Pathway
Form for Investigations can be used to
record the results.
It may be necessary to make observa-
tions under different conditions, as airflow
direction can change depending upon
weather conditions, windspeed and
direction, equipment operation within the
building, traffic through doors, and other
factors (e.g., as VAV systems throttle
back). Switching air handlers or exhaust
fans on and off, opening and closing doors,
and simulating the range of operating
conditions in other ways can help to show
the different ways that airborne contami-
nants move within the building. Dust
tracking patterns around door frames can
reveal the dominant direction of air and
pollutant movement.
Some investigators study air movement
by releasing a small amount of peppermint
oil at the opening to a suspected pathway
and asking an assistant to sniff for the
Sample Form
Pollutant Pathway Form for Investigations
-This form should be used in combination with a floor plan such as a fire
^evacuation plan.
Building areas that appear isolated from each other may be connected by
airflow passages such as air distribution zones, utility tunnels Or chases, party
walls, spaces above suspended ceilings (whether or not those spaces are
serving as air plenums), elevator shafts, and crawl spaces.
Rooms or Zones
Connected to the
Complaint Area by
Pathways
Use
: -
Pressure Relative to
Complaint Area
+/-
date/time
Comments
(e.g., potential
polluntant
sources)
"toothpaste" smell. If this technique is
used, it is important that the assistant have
an acute sense of smell. If the building is
in use during the investigation, occupants
may also notice the odor and could find it
distracting. Some investigators prefer to
use methods that release an odor during
unoccupied periods. Investigators should
note two common causes of false negative
results (falsely concluding that no pathway
exists):
The nose quickly becomes tolerant of
strong odors, so that the assistant may
need to take a long rest (breathing fresh
air) between tests.
If there is substantial airflow through the
pathway, the peppermint oil odor could
be diluted so that it is imperceptible.
Tracer gases such as sulfur hexafluo-
ride (SF6) can provide qualitative and
quantitative information on pollutant path-
ways and ventilation rates. Use of tracer
gases to obtain quantitative results
requires considerable technical expertise.
If it appears that a sophisticated study of
pathways (or ventilation rates) is required,
you need to use trained investigators.
Diagnosing IAQ Problems 69
-------
USING POLLUTANT PATHWAY
DATA
Pollutant pathway information helps the
investigator to understand airflow patterns
in and around the complaint area. The
pollutant pathway data may indicate a need
to enlarge the complaint area, or may direct
attention toward contaminant sources that
deserve close study.
Strategies for Using Pathway
Information
Evaluate airflow patterns
Confirm or revise boundaries of the com-
plaint area
Ao
Computer Room
receptionist and office occupants in
Zone 1 have complained of food odors.
The investigator is using a fire escape
plan to record air movement, sources,
and complaint information. The inves-
tigator has noted one hypothesis about
the cause of the complaints in the room
marked "Lounge."
70 Section 6
-------
Evaluate Airflow Patterns
Evaluate airflow patterns into and
within the complaint area. Because of
the complexity and variability of air-
flow patterns, investigators cannot be
expected to understand how air moves
within the building under all potential
operating conditions. However, data
on pathways and driving forces can
help to locate potential pollutant
sources and to understand how con-
taminants are transported to building
occupants.
ฃ AIRFJLQW PATTERNS
SUGGESTIONS
Look for temporal patterns
linking changes in airflow
direction to incidents of
complaints.
Look for spatial patterns
linking potential sources to
the locations of complaints.
Confirm or Revise Boundaries
of the Complaint Area
The discovery of unexpected pollutant
pathways can show a need to study
areas of the building that may be
distant from the original complaint
area.
COMPLAINT AREA
Complaint area connected
ft? tby architectural features to
=*(-_ฃ*.* ปป
ifotper areas
area connected
, 3 by mecanical system to
.Dther areas
fUnintentkmal pathways
(e.g., cracks, holes)
SUGGESTIONS
Check whether pressure relation-
ships between complaint area and
surrounding locations follows
intent of ventilation design.
Check whether air from other
locations flows into the complaint"
area under some conditions. If so/
consider expanding the investiga-
tion to inventory pollutant sources
{and perhaps collect HVAC or
occupant data) in those locations.
WHAT DO YO
1C OWSOFA ?
Use the Hypothesis. *
Form on page 223 to
make brief notes after
reviewing the pollutant
pathway data.
Decide whether you
have a hypothesis that
might explain the
complaints. If so, test
it. (See page 78 for a
discussion of hypoth-
esis testing.)
Decide what else you
need to know. Con- ;
sider whether in-house
expertise is sufficient
or outside assistance is
needed. (See Section 8 ,"
for guidance on hiring
outside assistance.)
Diagnosing IAQ Problems 71
-------
COLLECTING SOURCE INFORMATION
Strปt*gt*ซ Tools
Conduct on sita
inspection
Pollutant and Source Inventory
i Chemical Inventory
Talk wfth building
occupants, facilities
staff, and contractors
i Pollutant and Source Inventory
: Chemical inventory
Satnpf* Form
Pollutant and Source Inventory
f, , & .;,-ซ.-'',; f, ''.;"; - i, t!.;,', ,
Using the list of potential source categories below, record any
indications of contamination or suspected pollutants that may
require further investigation or treatment
Sourc* C*tปfl
-------
Inquire about outdoor ambient air
problems in the area. (This information
may be available from your local Health
Department.)
Observe soil gas entry points.
Inventory equipment sources
Review non-HVAC equipment, particu-
larly large office equipment such as
engineering drawing reproduction
machines and wet-process copiers.
Learn about usage patterns and identify
items that are not equipped with local
exhaust.
Review biocides and water treatments
used on HVAC equipment.
Review building components and
furnishings
Check drain traps to make sure they are
not dry.
Identify areas of excessive dust and/or.
deteriorated furnishings.
Identify areas of soil or water damage.
Identify locations of new furnishings.
Inventory other potential sources
Identify special use areas such as
smoking lounges, laboratories, print
shops.
Identify areas where remodeling, repair,
or redecorating activities are in progress
or recently completed. Check proce-
dures being used to isolate demolition
dust, paint fumes, and other contami-
nants related to the process.
Inventory cleaning materials used in the
building.
(See Section 4 for another discussion of
problem indicators and common problems
that may become obvious during a
walkthrough of the building.)
The Pollutant and Source Inventory
can be used to record your observations.
The Chemical Inventory form is intended
to serve as a record of materials such as
solvents, biocides, pesticides, and cleaning
compounds that may require special care in
storage and handling. Material Safety
Data Sheets (MSDSs) should be collected
on these materials whenever possible.
(See Section 4 for further discussion of
MSDSs.) Portions of both forms are
shown on the opposite page; the complete
form is included in Tab V.
Talk With Building Occupants
and Facility Staff
Building occupants and facility staff can
provide valuable information about the
location and timing of activities that
produce odors or contaminants (e.g.,
smoking, cooking, housekeeping, mainte-
nance). They may also suggest explana-
tions for the IAQ problem that can help in
the development of hypotheses. Facility
staff and outside contractors (e.g., persons
involved in housekeeping, pest control, or
remodeling) should be interviewed or
asked to provide a current list of materials,
procedures, and schedules used for
cleaning and pest control.
It may be useful to discuss the following
items with building occupants:
Inventory activities
Review smoking policy (and actual
practice; cleaning staff may know where
smoking occurs in violation of policy,
especially in private offices).
Identify areas of overcrowding.
Review products used for housekeeping,
maintenance, and pest control and the
schedules of their use.
Inquire about housekeeping schedules
and procedures.
Identify supply storage areas and check
for well-sealed containers and proper
ventilation.
Discuss incidents that could be sources
Inquire about prior and neighboring uses
of land (e.g., landfills, underground fuel
tanks).
Inquire about events such as spills, fires,
or leaks.
If such events have occurred, learn what
remedial actions were taken to clean up
after the incidents and to prevent their
recurrence.
Diagnosing IAQ Problems 73
-------
PATTERNS
SUGGESTIONS
Location(s)
of sources
Compare locations of sources to locations of
complaint(s).
Identify pathways linking potential sources to the
complaint area.
Revise definition of complaint area if necessary.
Timing Note whether the sources emit on a continuous
of emissions or intermittent basis.
Compare the timing of emissions to the timing
of complaints.
Identify occasions when the source is likely to be
strongest.
Determine whether pathways between the
source(s) and the complaint location could
account for the occasions of complaints.
WHAT DO YOU
KNOW SO FAR?
* Use the Hypothesis
Form on page 223
to make brief notes
after reviewing the
pollutant source
data.
Decide whether you
have a hypothesis
that might explain
the complaints. If
so, test it. (See page
78 for a discussion
of hypothesis
testing.)
Decide what else
you need to know.
Consider whether in-
house expertise is
sufficient or outside
assistance is needed.
(See S&ction 8 for
guidance on hiring
outside assistance.)
USING POLLUTANT SOURCE
DATA
If a strong pollutant source is identified in
the immediate vicinity of the complaint, a
simple test (e.g., sealing, covering, or
removing the source) can sometimes reveal
whether or not it is the cause of the IAQ
problem. If a number of potential sources
have been found in and around the
complaint area, other data (e.g., the pattern
of symptoms, the HVAC system design
and operation, and pollutant pathways)
may be needed in order to determine which
source(s), if any, may be related to the
complaint.
Strategies for Using Source
Information
Identify patterns linking emissions to
complaints
Evaluate unrelated sources
Identify Patterns Linking
Emissions to Complaints
Look for patterns linking emissions from
potential sources to the IAQ complaints.
Evaluate Unrelated Sources
Evaluate sources that appear unrelated to
the complaints. It is not unusual to
identify potential contaminant sources that
are unrelated to the present IAQ complaint
(i.e., either the location of the source, the
timing of emissions, or both fit poorly with
the pattern of complaints). These should
be prioritized for remedial work according
to their potential for causing health
problems or complaints in the future.
A detailed study of pollutants and
sources may involve an engineering
evaluation of equipment that is releasing
IAQ contaminants, diagnostic sampling to
assess sources in operation, or other
measurements. These may require skills or
instruments that are not available in-house.
SAMPLING AIR FOR
CONTAMINANTS AND
INDICATORS
Although air sampling might seem to be
the logical response to an air quality
problem, such an approach may not be
required to solve the problem and can even
be misleading. Air sampling should not be
undertaken until some or all of the other
investigative activities mentioned previ-
ously have been used to collect consider-
able information. Before beginning to take
air samples, investigators should develop a
sampling strategy that is based on a
comprehensive understanding of how the
building operates, the nature of the
complaints, and a plan for interpreting the
results.
It may be desirable to take certain
routine air quality measurements during an
investigation to obtain a "snapshot" of
current conditions. These tests should be
limited to those that are indicative of very
common IAQ concerns such as tempera-
ture, relative humidity, air movement, or
carbon dioxide (CO2). Unusual readings
may or may not indicate a problem, and
should always be interpreted in perspec-
tive, based upon site-specific conditions.
Measurement of specific chemical or
biological contaminants can be very
expensive. Before expending time and
74 Section 6
-------
money to obtain measurements of indoor
air pollutants, you must decide:
how the results will be used
(e.g., comparison to standards or
guidelines, comparison to levels in
complaint-free areas)
what substances(s) should be measured
where to take samples
when to take samples
what sampling and analysis method to
use so that the results provide useful
information
It is often worthwhile for building staff
to develop skills in making temperature,
humidity, airflow, and CO2 measurements
and assessing patterns of air movement
(e.g., using chemical smoke). Appendix A
provides a brief introduction to ventilation
and thermal measurement strategies and to
methods of sampling for specific air
contaminants.
How Will the Results Be Used?
Although air sampling will generate
numbers, it will not necessarily help
resolve the IAQ problem. Many IAQ
complaints are resolved without sampling
or with inconclusive sampling results.
The design of an air sampling strategy
should fit the intended use of the measure-
ments. Potential uses of indoor air
measurements include:
1. Comparing different areas of the building
or comparing indoor to outdoor condi-
tions in order to:
Confirm that a control approach has
the desired effect of reducing pollutant
concentrations or improving ventilation
Establish baseline conditions so that
they can be compared to concentrations
at other times or locations, such as
concentrations in outdoor air
concentrations in areas where no
symptoms are reported
expected "background" range for
typical buildings without perceived
IAQ problems
Test a hypothesis about the source of
the problem, such as
checking emissions from a piece, of
equipment
2. Testing for "indicator" compounds
associated with particular types of
building conditions:
Peak carbon dioxide (CO2) concentra-
tions over 1000 ppm (parts per million)
are an indicator of underventilation
Carbon monoxide (CO) over several
ppm indicates inappropriate presence
of combustion by-products (which may
also account for high CO2 readings)
3. Comparing measured concentrations to
guidelines or standards
Occupational exposure standards and
guidelines^ such as
OSHA PELs (Occupational Safety and
Health Administtatton's Permissible
Exposure Limits)
NIOSH RELs (National Institute for
Occupational Safety and Health's
Recommended Exposure Limits)
B ACGIH TLVs (American Conference
of Governmental Industrial Hygienists'
Threshold Limit Values)
Occupants in this one-story
office building were com-
plaining of Intermittent
gasoline odors. Exhausts
from underground gasoline
storage tank vent pipes
(visible in the lower right
portion of this photograph)
were being drawn into the
office building through
outdoor air intakes on this
roof. The gasoline storage
tanks belonged to an adja-
cent service station.
Diagnosing IAQ Problems 75
-------
It Is prudent to begin
a program of chemical
sampling only if
symptoms or observa-
tions strongly suggest
that a specific pollut-
ant or a specific
source may be the
cause of the com-
plaint and if sampling
results are important
in determining an
appropriate corrective
action.
Public health guidelines for specific
pollutants
m EPA National Ambient Air Quality
Standards
World Health Organization Air
Quality Guidelines
Canadian Exposure Guidelines for
Residential Air Quality
There are no widely accepted procedures
to define whether IAQ test results are ac-
ceptable. Extreme caution must be used in
comparing contaminant concentrations to
existing occupational standards and guide-
lines. Although a contaminant concentra-
tion above those guidelines is a clear prob-
lem indicator, occupants may still experi-
ence health and comfort problems at con-
centrations well within those guidelines. It
is extremely rare for occupational stan-
dards to be exceeded or even ap-
proached in public and commercial
buildings, including those experiencing
indoor air quality problems.
Where specific exposure problems are
suspected, more detailed diagnostic testing
may be needed to locate or understand
major sources, confirm the exposure, and
to develop appropriate remedial actions.
For example, the control of microbial or
pesticide contamination may involve sur-
face or bulk sampling. (Surface sampling
involves wiping a measured surface area
and analyzing the swab to see what organ-
isms are present, while bulk sampling
involves analyzing a sample of suspect
material.) Specialized skills, experience,
and equipment may be needed to obtain,
analyze, and interpret such measurements.
What Substance(s) Should Be
Measured?
Measurement of "indicator" compounds
such as CO2 or CO can be a cost-effective
strategy. Such measurements can help the
investigator understand the nature of the
problem and define the complaint area.
Air sampling for specific pollutants
works best as an investigative tool when it
is combined with other types of informa-
tion-gathering. It is prudent to begin a
program of chemical sampling only if
symptoms or observations strongly suggest
that a specific pollutant or a specific source
may be the cause of the complaint and if
sampling results are important in determin-
ing an appropriate corrective action.
Where Should Air Samples Be
Taken?
The identified problem area is an obvious
site for air sampling. Measurements taken
outdoors and in a control location (e.g., a
complaint-free area of the building) are
helpful in interpreting results from the
complaint area.
The conditions experienced by building
occupants are best simulated by sampling
air from the "breathing zone" away from
the influence of any particular individual.
However, if an individual sits at a desk all
day (except for brief periods), samplers
placed on the desk when the individual is
elsewhere can provide a good estimate of
that person's exposure.
There are several ways to locate sam-
pling sites for an IAQ investigation. One
approach first divides the building into
homogeneous areas based on key factors
identified in the building inspection and
interviews. Examples of how a building
might be divided include;
control zones (e.g., individual rooms)
types of HVAC zones (e.g., interior vs.
perimeter)
complaint vs. non-complaint areas
relationship to major sources
(e.g., spaces directly, indirectly, or not
impacted by smoking areas)
complaint types
Test sites can then be selected to repre-
sent complaints, controls, and potential
sources with a reasonable number of
samples.
76 Section 6
-------
When Should Air Samples Be
Taken?
Samples may be designed to obtain "worst-
case" conditionSj.such as measurements
during periods of maximum equipment
emissions, minimum ventilation, or distur-
bance of contaminated surfaces. Worst-
case sample results can be very helpful in
characterizing maximum concentrations to
which occupants are exposed and identify-
ing sources for corrective measures^
It is also helpful to obtain samples during
average or typical conditions as a basis of
comparison. It may, however, be difficult
to know what conditions are typical. Re-
search shows that exposure to some pollut-
ants may vary dramatically as building
conditions change. Devices that allow
continuous measurements of key variables
can be helpful.
Symptoms or odors that only occur occa-
sionally will not generally be seen during
the IAQ investigation. Air samples should
not be taken if an incident is not occurring,
unless the purpose of the sample is to es-
tablish a baseline for future comparisons.
One approach to intermittent IAQ prob-
lems is for the IAQ investigator to ask
appropriate building staff or other occu-
pants to document changes over time using
day-to-day records such as the Occupant
Diary and Log of Activities and System
Operation. When an odor episode does
occur, the building engineer could inspect
the air handler and intake area while an-
other staff member documents the status of
several potential sources.
Another strategy is to manipulate
building conditions to create worst-case
conditions during the building investiga-
tion (e.g., arrange for the trash track to idle
at the loading dock or close outdoor air
dampers to minimum settings). Chemical
smoke and tracer gases can be used to
assess where emissions may travel under
various building conditions. (Such
strategies should be carried out in ways
that minimize occupant exposure.)
What Sampling and Analysis
Method Should Be Used?
Take care to select appropriate measure-
ment techniques and to provide interpret-
ations so that the results provide useful
information. Appendix A provides
guidance on measurement techniques that
are commonly used in IAQ investigations.
COMPLAINTS DUE TO
CONDITIONS OTHER THAN
POOR AIR QUALITY
Complaints that initially seem to be linked
to thermal discomfort, underventilation, or
indoor air pollutants may actually be
caused or complicated by factors such as:
environmental stressors (e.g., lighting,
noise, vibration)
ergonomic stressors
job-related psychosocial (human rela-
tions) stressors
The following briefly discusses each of
these three kinds of stressors. Investiga-
tors should bear in mind that complaints
produced by these stressors are sometimes
mistakenly blamed on contaminated air.
To complicate matters, such stressors also
can produce a heightened sensitivity to
poor indoor air quality. Thus, even when
specific stressors are obvious, the investi-
gator should not assume that they are the
only reason for the complaints.
Lighting
Stresses from inadequate or poorly
designed lighting (e.g., glare, flicker, poor
illumination of work surfaces) can produce
symptoms such as eyestrain and head-
aches. Lack of natural sunlight can also be
a source of stress. These complaints are
sometimes mistakenly interpreted as signs
of poor indoor air quality. Lighting
problems may be evident in large areas or
localized in particular workspaces.
Investigators should
bear in mind that
complaints produced
by these stressors are
sometimes mistakenly
blamed on contami-
nated air. To compli-
cate matters, such
stressors also can
produce a heightened
sensitivity to poor
indoor air quality.
Diagnosing IAQ Problems 77
-------
The glare from the windows
was causing a variety of
occupant complaints in this
building and was disrupting
th0 workers' ability to use
the video display terminals.
Complaints such as
headaches are sometimes
incorrectly blamed on poor
indoor air quality.
Noise
Noisy surroundings can reduce the ability
to concentrate and produce stress-related
symptoms such as headaches. Noise can
also contribute to job dissatisfaction,
particularly if the problem is caused by
overcrowding or other factors likely to
produce a sense of substandard work
conditions.
The ear gets used to sounds quickly, so it
is possible for a complainant to be unaware
of a constant or regular sound. Investiga-
tors should recognize that noise can be a
source of stress, even if it is not reported as
a problem and is within current industrial
exposure criteria (which are designed
primarily to prevent hearing loss).
Vibration
Low-frequency vibration is another source
of stress that may go unreported by
building occupants or become confused
with pollutant problems. Vibration can be
caused by nearby machinery or movement
of the building as a whole; motion sickness
has been reported in some high rise
buildings that sway in the wind.
Ergonomic Stressors
Fatigue, circulatory problems, and other
physical problems can be produced by
furniture that is mismatched to the task,
such as chairs that are the wrong height for
computer terminals. If IAQ investigators
inquire about whether new furniture has
recently been installed in the problem area
(to determine if the furniture could be
contributing to increased contaminant
levels), they should also ask about
whether the occupant finds the furniture
comfortable.
Job-related Psychosocial
Stressors
It is well documented that various job-
related psychosocial conditions can
produce symptoms in workers. Excessive
workload and work pressure are easily
recognized job Stressors. Lack of clarity
about what is expected of the worker (role
ambiguity) and the presence of conflicting
expectations (role conflict) are also
commonly encountered Stressors in
modem organizations. Poor interpersonal
relations, management styles that allow
little participation in decision-making, and
factors related to career development are
also thought to be potentially stressful.
FORMING AND TESTING
HYPOTHESES
As the building investigation progresses,
you should be developing one or more
hypotheses that could explain the occupant
complaints. The investigation can then be
shaped to collect information that will
either support or refute your hypotheses.
The Hypothesis Form on the opposite
page is designed to pull together the
separate pieces of information that have
been collected by summarizing the results
of the investigation. More pages can be
added if desired, but the form is designed
for brief notes that can be scanned easily.
As you review the information, write down
78 Section 6
-------
any explanation^) of the IAQ problem that
make sense, and think about how the
pieces of the puzzle fit together when
building conditions are compared to
occupant complaints.
Is aH (or most) of your information
consistent with your hypothesis? If not, is
there a reasonable explanation for the
inconsistencies? A different hypothesis
might provide a better fit with your
information.
You may find that there are several IAQ
problems (e.g., underventilation in one
zone, a strong contaminant source in,
another room). If you have discovered
potential LAQ problems that do not appear
related to the original complaint, they can
be prioritized and corrected as time and
funding permit.
Think of ways to test your hypotheses.
You may want to change ventilation rates,
change the pressure relationship between
spaces, cover or remove suspected sources,
seal pathways, or temporarily relocate
affected individuals. If your manipulations
can reduce occupant complaints, you have
found a reasonable hypothesis. Sometimes
it is not possible (or not practical) to
manipulate important factors. You can
also test your hypothesis by seeing how
accurately you can predict changes in
building conditions (e.g., as outdoor
temperature changes).
If you are having difficulty developing
hypotheses, review the information you
have collected and the suggestions aboat
how to use that information. For sugges-
tions on using occupant complaint data,
see pages 53-57; on using HVAC system
information, see pages 62-67; on using
pollutant pathway information, see pages
70-71; on using poEutant/source inventory
data, see page 74; on using air sampling
information, see pages 75-76.
Hie changes that are made during :~,
hypothesis testing may offer a practical
solution to the IAQ problem, or may be
only temporary measures. The mitigation
chapter presents a variety of approaches
that have been used in correcting some
selected categories of IAQ problems and
discusses how to evaluate those strategies.
COMPLETE
'RjiftM --..
PAGE 223
SampOฉ Form
Hypothesis Form
Complaint Area {may be revised as the investigation progresses):
^(Complaints {e.g., summarize patterns of timing, location, people
plfected);
HVAC: Does the ventilation system appear to provide adequate
litr, efficiently distributed to meet occupant needs In the complaint
Stria? If not, what problems do you see?
yPjrthways: What pathways and driving forces connect the
$n&rrfplaint,area to locations of potential sources?
Diagnosing IAQ Problems 79
-------
Page Intentionally Blank
-------
Mitigating IAQ Problems
"ver the years many types of mitigation.
(correction) strategies have been imple-
mented to solve indoor air quality prob-
lems. The purpose of this section is to
provide an understanding of basic ap-
proaches to mitigation and the various
solutions that can be effective in treating
commonly encountered IAQ problems. It
is not intended to provide detailed instruc-
tions for using each type of mitigation
approach but rather to give guidance in
selecting a mitigation strategy and in
judging proposals from in-house staffer
outside consultants.
Mitigation of indoor air quality prob-
lems may require the involvement of
building management and staff represent-
ing such areas of responsibility as:
facility operation and maintenance
housekeeping
shipping and receiving
purchasing
poh'cymaking
staff training
Successful mitigation of IAQ problems
also requires the cooperation of other
building occupants, including the employ-
ees of building tenants. Occupants must be
educated about the cause(s) of the IAQ
problems and about actions that must be
taken or avoided to prevent a recurrence of
the problems.
BACKGROUND: CONTROLLING
INDOOR AIR PROBLEMS
Section 2 introduced the idea mat indoor
air quality problems result from Interac-
tions between contaminant source,
building site, building structure, activities
within the building, mechanical equipment,
climate, and occupants. Efforts to control
indoor air contaminants change the
relationships between these factors. There
are many ways that people can intervene in
these relationships to prevent or control
indoor air contaminant problems. Control
strategies can be categorized as:
source control
ventilation
air cleaning
* exposure control
Successful mitigation often involves a
combination of these strategies. Possible
remedies for the other environmental
stressors discussed in Section 6 are
discussed briefly below.
Source Control
All efforts to prevent or correct IAQ
problems should include an effort to
identify and control pollutant sources.
Source control is generally the most cost
effective approach to mitigating IAQ
problems in which point sources of
contaminants can be identified. In the case
of a strong source, source control may be
the only solution that will work.
The following are categories and
examples of source control:
Remove or reduce the source
prohibit smoking indoors or limit
smoking to areas from which air is
exhausted, not reeirculated (NIOSH
regards smoking areas as an interim
solution)
relocate contaminant-producing equip-
ment to an unoccupied, better ventilated,
or exhaust-only ventilated space
select products which produce fewer or
legs potent contaminants while maintain-
ing adequate safety and efficacy
Mitigating IAQ Problems 81
-------
modify other occupant activities
Seal or cover the source
improve storage of materials that
produce contaminants
seal surfaces of building materials that
emit VOCs such as formaldehyde
Modify the environment
after cleaning and disinfecting an area
that is contaminated by fungal or
bacterial growth, control humidity to
make conditions inhospitable for
regrowth
Source removal or reduction can
sometimes be accomplished by a one-time
effort such as thorough cleaning of a spill.
In other cases, it requires an ongoing
process, such as establishing and enforcing
a non-smoking policy.
Sealing or covering the source can be a
solution in some cases; application of a
barrier over formaldehyde-emitting
building materials is an example. Sealing
may also involve educating staff or
building occupants about the contaminant-
producing features of materials and
supplies and inspecting storage areas to
ensure that containers are properly
covered.
In some cases, modification of the
environment is necessary for effective
mitigation. If the indoor air problem
arises from microbiological contaminants,
for example, disinfection of the affected
area may not eliminate the problem.
Regrowth of microbiologicals could
occur unless humidity control or other
steps, such as adding insulation to prevent
surface condensation, are taken to make
the environment inhospitable to micro-
biologicals.
Ventilation
Ventilation modification is often used to
correct or prevent indoor air quality
problems. This approach can be effective
either where buildings are underventilated
or where a specific contaminant source
cannot be identified. Ventilation can be
used to control indoor air contaminants by:
Diluting contaminants with outdoor air
increase the total quantity of supply air
(including outdoor air)
increase the proportion of outdoor air to
total air
improve air distribution
Isolating or removing contaminants by
controlling air pressure relationships
install effective local exhaust at the
location of the source
avoid recirculation of air that contains
contaminants
locate occupants near supply diffusers
and sources near exhaust registers
use air-tightening techniques to maintain
pressure differentials and eliminate
pollutant pathways
make sure that doors are closed where
necessary to separate zones
Diluting contaminants by increasing
the flow of outdoor air can be accom-
plished by increasing the total supply
airflow in the complaint area (e.g., opening
supply diffusers, adjusting dampers) or at
the air handling unit, (e.g., cleaning the
filter on the supply fan). An alternative is
to increase the proportion of outdoor air
(e.g., adjusting the outdoor air intake
damper, installing minimum stops on
variable air volume (VAV) boxes so that
they satisfy the outdoor air requirements of
ASHRAE 62-1989).
Studies have shown that increasing
ventilation rates to meet ASHRAE
Standard 62-1989 (e.g., from 5 to 15 or 20
cfm/person) does not necessarily signifi-
cantly increase the total annual energy
consumption. The increase appears to be
less than 5% in typical commercial
buildings. The cost of ventilation is
generally overshadowed by other operating
costs, such as lighting. Further, improved
maintenance can produce energy savings
to balance the costs that might otherwise
result from increased ventilation.
82 Section?
-------
The cost of modifying an existing
HVAC system to condition additional
outdoor air can vary widely depending
upon the specific situation. In some
buildings, HVAC equipment may not have
sufficient capacity to allow successful
mitigation using this approach.. Original
equipment is often oversized so that it can
be adjusted to handle the increased load,
but in some cases additional capacity is
required.
Most ventilation deficiencies appear to
be linked to inadequate quantities of
outdoor air. However, inadequate distribu-
tion of ventilation air can also produce
IAQ problems. Diffusers should be
properly selected, located, installed, and
maintained so that supply air is evenly
distributed and blends thoroughly with
room air in the breathing zone. Short-
circuiting occurs when clean supply air is
drawn into the return air plenum before it
has mixed with the dirtier room air and
therefore fails to dilute contaminants.
Mixing problems can be aggravated by
temperature stratification. Stratification
can occur, for example, in a space with
high ceilings in which ceiling-mounted
supply diffusers distribute heated air.
Note the side effects of increased
ventilation:
mitigation by increasing the circulation
of outdoor air requires good outdoor air
quality
increased supply air at the problem
location might mean less supply air in
other areas
increased total air in the system and
increased outdoor air will both tend to
increase energy consumption and may
require increased equipment capacity
any approach which affects airflow in the
building can change pressure differences
between rooms (or zones) and between
indoors and outdoors, and might lead to
increased infiltration of unconditioned
outdoor air
increasing air in a VAV system may
overcool an area to the extent that
terminal reheat units are needed
Ventilation equipment can be used to
isolate or remove contaminants by
controlling pressure relationships. If the
contaminant source has been identified,
this strategy can be more effective than
dilution. Techniques for controlling air
pressure relationships range from adjust-
ment of dampers to installation of local
exhaust.
Using local exhaust confines the spread
of contaminants by capturing them near the
source and exhausting them to the out-
doors. It also dilutes the contaminant by
drawing cleaner air from surrounding areas
into the exhaust airstream. If there are
return grilles in a room equipped with local
exhaust, the local exhaust should exert
enough suction to prevent recirculation of
contaminants. Properly designed and
installed local exhaust results in far lower
contaminant levels in the building than
could be accomplished by a general
increase in dilution ventilation, with the
added benefit of costing less.
Note that replacement air must be able
to flow freely into the area from which the
exhaust air is being drawn. It may be
necessary to add door or wall louvers in
order to provide a path for the make-up air.
(Make sure that this action does not violate
fire codes.)
Correct identification of the pollutant
source and installation of the local exhaust
is critically important. For example, an
improperly designed local exhaust can
draw other contaminants through the
occupied space and make the problem
worse.
The physical layout of grilles and
diffusers relative to room occupants and
pollutant sources can be important If
supply diffusers are all at one end of a
room and returns are all at the other end,
the people located near the supplies may
be provided with relatively clean air while
those located near the returns breathe air
that has already picked up contaminants
from aH the sources in the room that are
not served by local exhaust.
Mitigating IAQ Problems 83
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Elimination of pollutant pathways by air
sealing (e.g., caulking cracks, closing
holes) is an approach that can increase the
effectiveness of other control techniques.
It can be a difficult technique to implement
because of hidden pathways (e.g., above
drop ceilings, under raised flooring,
against brick or block walls). However, it
can have olfaer benefits such as energy
savings and more effective pest control (by
eliminating paths used by -vermin),
Air Cleaning
The third IAQ control strategy is to clean
the air. Air cleaning is usually most effec-
tive when used in conjunction with either
source control or ventilation; however, it
may be the only approach when the source
of pollution is outside of the building.
Most air cleaning in large buildings is
aimed primarily at preventing contaminant
buildup in HVAC equipment and enhanc-
ing equipment efficiency.
Air cleaning equipment intended to
provide better indoor air quality for occu-
pants must be properly selected and de-
signed for the particular pollutants of inter-
est (for example, gaseous contaminants can
be removed only by gas sorption). Once
installed, the equipment requires regular
maintenance in order to ensure good per-
formance; otherwise it may become a
major pollutant source in itself. This main-
tenance requirement should be borne in
mind if an air cleaning system involving a
large number of units is under consider-
ation for a large building. If room units are
used, the installation should be designed
for proper air recirculation.
There are four technologies that remove
contaminants from the air:
paniculate filtration
electrostatic precipitation
* negative ion generation
gas sorption
The first three approaches are designed
to remove particulates, while the fourth is
designed to remove gases.
Particmlate filtration removes sus-
pended liquid or solid materials whose
size, shape and mass allow them to remain
airborne at the air velocity conditions
present Filters are available in a range of
efficiencies, with higher efficiency indicat-
ing removal of a greater proportion of
particles and of smaller particles.. Moving
to medium efficiency pleated filters is
advisable to improve IAQ and increase
protection for equipment However, the
Mgher the efficiency of the filter, the more
it will increase the pressure drop within the
air distribution system and reduce total
airflow (unless other adjustments are made
to compensate). It is important to select an
appropriate filter for the specific
application and to make sure that the
HVAC system will continue to perform as
designed. Filters are rated by different
standards (e.g., arrestance and dust spot)
which measure different aspects of
performance, .
Electrostatic precipitation is another
type of particulate control. It uses the
attraction of charged particles to oppositely
charged surfaces to collect airborne par-
ticulates, In this process, the particles are
charged by ionizing the air with an electric
field. The charged particles are then col-
lected by a strong electric field generated
between oppositely-charged electrodes.
This provides relatively high efficiency
filtration of small respirable particles at
low air pressure losses.
Electrostatic precipitators may be in-
stalled in air distribution equipment or in
specific usage areas. As with other filters,
they must be serviced regularly. Note,
however, that electrostatic precipitators
produce some ozone. Because ozone is
harmful at elevated levels, EPA has set
standards for ozone concentrations in out-
door air, and NIOSH and OSHA have
84 Section?
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established guidelines and standards, re-
spectively, for ozone in indoor air. The
amount of ozone emitted from electrostatic
precipitators varies from model to model.
Negative ion generators use static
charges to remove particles from the indoor
air. When the particles become charged,
they are attracted to surfaces such as walls,
floors, table tops, draperies, and occupants.
Some designs include collectors to attract
the charged particles back to the unit.
Negative ion generators are not available
for installation in ductwork, but are sold as
portable or ceiling-mounted units. As with
electrostatic precipitators, negative ion
generators may produce ozone, either inten-
tionally or as a by-product of use.
Gas sorption is used to control com-
pounds that behave as gases rather than as
particles (e.g., gaseous contaminants such
as formaldehyde, sulfur dioxide, ozone, and
oxides of nitrogen). Gas sorption involves
one or more of the following processes
with the sorption material (e.g., activated
carbon, chemically treated active clays): a
chemical reaction between the pollutant
and the sorbent; a binding of the pollutant
and the sorbent; or diffusion of the con-
taminant from areas of higher concentration
to areas of lower concentration. Gas sorp-
tion units are installed as part of the air
distribution system. Each type of sorption
material performs differently with different
gases. Gas sorption is not effective for
removing carbon monoxide. There are no
standards for rating the performance of
gaseous air cleaners, making the design and
evaluation of such systems problematic.
Operating expenses of these units can be
quite high, and the units may not be effec-
tive if there is a strong source nearby.
Exposure Control
Exposure control is an administrative ap-
proach to mitigation that uses behavioral
methods, such as:
Scheduling contaminant-producing activi-
ties to avoid complaints
schedule contaminant-producing activi-
ties to occur during unoccupied periods
notify susceptible individuals about up-
coming events (e.g., roofing, pesticide
application) so that they can avoid contact
with the contaminants
Scheduling contaminant-producing ac-
tivities for unoccupied periods whenever
possible is simple common sense. It may
be the best way to limit complaints about
activities (such as roofing or demolition)
which unavoidably produce odors or dust.
Relocating susceptible individuals
move susceptible individuals away from
the area where they experience symptoms
Controlling exposure by relocating sus-
ceptible individuals may be the only practi-
cal approach in a limited number of cases,
but it is probably the least desirable option
and should be used only when all other
strategies are ineffective in resolving com-
plaints.
Remedies for Complaints Not
Attributed to Poor Air Quality
Specific lighting deficiencies or localized
sources of noise or vibration can sometimes
be readily identified, and remedial action
may be fairly straightforward (more or
fewer lights on, adjustments for glare; relo-
cating, replacing or acoustically insulating a
noise or vibration source). Similarly, fla-
grant ergonomic stress or blatant
psychosocial stress may be apparent even to
an untrained observer.
In other cases, however, problems may
be more subtle or solutions more complex.
Since specialized knowledge, skills, and
instrumentation are usually needed to
evaluate lighting, noise, vibration, ergo-
nomic stress, or psychosocial stress, such
evaluations are generally best done by a
qualified professional in that particular
field.
Mitigating IAQ Problems 85
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Remedial actions for lighting, noise,
and vibration problems might range from
modifications of equipment or furnishings
to renovation of the building, Ergonomic
deficiencies may require furniture or
equipment changes or different work
practices. The solution to psychosocial
problems may involve new management
practices, job redesign, or resolution of
underlying labor-management problems.
SAMPLE PROBLEMS AND
SOLUTIONS
In the investigation section you were
introduced to a variety of problems that are
often found in buildings. This section
presents fifteen categories of IAQ prob-
lems. Specific problem "examples" are
given, followed by "solutions" that have
been used for that category of problem.
Most of the problems presented here are
common and do not have serious, life-
threatening consequences. At the end of
the section is a brief description of
problems that can have severe health
impacts. The basic correction principles
that apply to these serious problems are
similar to those used in less critical
situations.
Reading these examples may help you
think about the best way to solve your
indoor air quality problems. Remember
that these are brief sketches, and apparent
parallels to your building could be mis-
leading. It is better to carry out a building
investigation and learn the specific facts in
your own case, rather than adopt a mitiga-
tion approach that might not be appropri-
ate. Attempting to correct IAQ problems
without understanding the cause of those
problems can be both ineffective and
expensive.
You will note that some solutions are
simple and low-cost, while others are
complex and expensive. Do not assume
that each solution listed would be an
effective treatment for all of the problems
in its category.
The example problems and solutions are
presented in the following sequence:
Problem #1; Outdoor air ventilation rate
is too low
Problem #2: Overall ventilation rate is
high enough, but poorly
distributed and not sufficient
to some areas
Problem #3: Contaminant enters building
from outdoors
Problem #4: Occupant activities contrib-
ute to air contaminants or to
comfort problems
Problem #5; HVAC system is a source of
biological contaminants
Problem #6: HVAC system distributes
contaminants
Problem #7;' Non-HVAC equipment is a
source or distribution mecha-
nism for contaminants
Problem #8: Surface contamination due to
poor sanitation or accidents
Problem #9: Mold and mildew growth
due to moisture from con-
densation
Problem #10: Building materials and
furnishings produce
contaminants
Problem #11: Housekeeping or mainte-
nance activities contribute to
problems
Problem #12: Specialized use areas as
sources of contaminants
Problem #13: Remodeling or repair activi-
ties produce problems
Problem #14: Combustion gases
Problem #15: Serious building-related
illness
86 Section?
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Problem #1:
Outdoor Air Ventilation
Rate is Too Low
Examples
Routine odors from occupants and
normal office activities result in problems
(e.g., drowsiness, headaches, discomfort)
Measured outdoor air ventilation rates do
not meet guidelines for outdoor air supply
(e.g., design specifications, applicable
codes, or ASHRAE 62-1989)
Peak CO2 concentrations above 1000
ppm indicate inadequate ventilation
Corrosion of fan casing causes air
bypassing and reduces airflow in system
Solutions
.
Open, adjust or repair air distribution
system
outdoor air intakes
mixing and relief dampers
supply diffusers
fan casings
Increase outdoor air within the design
capacity of
air handler
heating and air conditioning equipment
distribution system
Modify components of the HVAC system
as needed to allow increased outdoor air
(e.g., increase capacity of heating and
cooling coils)
Design and install an updated ventilation
system
Reduce the pollutant and/or thermal load
on the HVAC system
reduce the occupant density: relocate
some occupants to other spaces to
redistribute the load on the ventilation
system
relocate or reduce usage of heat-
generating equipment
Malfunctioning controls such as this
broken damper linkage can virtually
eliminate intake of outdoor air. Such
problems may go undetected for years
without a careful investigation of the
HVAC system components.
Mitigating IAQ Problems 87
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Problem #2:
Overall Ventilation Rate Is
High Enough, But Poorly
Distributed and Not
Sufficient in Some Areas
Complaining of discomfort, building
occupants blocked air supply diffusers in
their work areas. The HVAC system in
this building was in poor condition and
was not balanced.
Examples
Measured outdoor air meets guidelines at
building air inlet, but there are zones
where heat, routine odors from occu-
pants, and normal office activities result
in complaints
(e.g., drowsiness, headaches, comfort
complaints)
Solutions
Open, adjust, or repair air distribution
system
supply diffusers
return registers
Ensure proper air distribution
balance the air handling system
make sure that there is an air gap at tops
and bottoms of partitions to prevent dead
air space
relocate supply and/or return diffusers to
improve air distribution
Seal leaky ductwork
Remove obstructions from return air
plenum
Control pressure relationships
install local exhaust in problem areas
and adjust HVAC system to provide
adequate make-up air
move occupants so that they are closer to
supply diffusers
relocate identified contaminant sources
closer to exhaust intakes
Reduce source by limiting activities or
equipment use that produce heat, odors,
or contaminants
Design and install an appropriate
ventilation system
88 Section?
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Problem #3:
Contaminant Enters Building
From Outdoors
Examples
Soil gases
(e.g., radon, gasoline from tanks, methane
from landfills)
Contaminants from nearby activities
(e.g., roofing, dumpster, construction)
Outdoor air intake near source
(e.g., parking, loading dock, building
exhaust)
Outdoor air contains pollutants or excess
moisture
(e.g., cooling tower mist entrained in
outdoor air intake)
Solutions
Remove the source (if it can be moved
easily)
remove debris around outdoor air intake
relocate dumpster
Reduce source (for example, shift time of
activity to avoid occupied periods)
painting, roofing, demolition
housekeeping, pest control
Relocate elements of the ventilation
system that contribute to entry of outdoor
air contaminants
separate outdoor air intakes from sources
of odors, contaminants
separate exhaust fan outlets from
operable windows, doors, air intakes
make rooftop exhaust outlets taller than
intakes
ter,
Change air pressure relationships to
control pollutant pathways
install subslab depressurization to
prevent entry of soil gas contaminants
(radon, gases from landfills and under-
ground tanks)
pressurize the building interior relative to
outdoors (this will not prevent contami-
nant entry at outdoor air intakes)
close pollutant pathways (e.g., seal
cracks and holes)
Add special equipment to HVAC system
filtration equipment to remove pollutants
(select to fit the situation)
For cosmetic reasons, air
intakes are frequently
located on rooftops or near
the ground. This air intake
could become a means of
drawing lawn cuttings,
vehicle exhaust, and
pesticides into the building.
Mitigating IAQ Problems 89
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Problem #4;
Occupant Activities
Contribute to Air
Contaminants or to
Comfort Problems
Personal equipment such as humidifiers
brought in by building occupants can
become a source of contaminants if not
properly maintained. An effective
communication strategy can help
occupants to understand their role in
causing indoor air quality problems and
in correcting those problems.
Examples
Smoking
Special activities such as print shops,
laboratories, kitchens
Interference with HVAC system
operation:
blockage of supply diffusers to eliminate
drafts
turning off exhaust fans to eliminate
noise
use of space heaters, desktop humidifiers
to remedy local discomfort.
(Note: While such interference can cause
IAQ problems, it is often initiated in
response to unresolved ventilation or
temperature control problems.)
Solutions
Remove the source by eliminating the
activity
(Note: This may requke a combination of
policy-setting and educational outreach.)
smoking
use of desktop humidifiers and other
personal HVAC equipment
unsupervised manipulation of HVAC
system
Reduce the source
m select materials and processes which
minimize release of contaminants while
maintaining adequate safety and efficacy
(e.g., solvents, art materials)
Install new or improved local exhaust to
accommodate the activity, adjust HVAC
system to ensure adequate make-up air,
and verify effectiveness
smoking lounge, storage areas which
contain contaminant sources
laboratory hoods, kitchen range hoods
(venting to outdoors, not recirculating)
90 Section?
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Problem #5;
HVAC System is a Source of
Biological Contaminants
The HVAC system can act as a source of
contaminants by providing a hospitable
environment for the growth of microorgan-
isms and then distributing biologically-
contaminated air within the building.
Examples
Surface contamination by molds (fungi),
bacteria
m drain pans
interior of ductwork
air filters and filter media (collected
debris).
Solutions
Remove source by improving mainte-
nance procedures
m inspect equipment for signs of corrosion,
high humidity
replace corroded parts
clean drip pans, outdoor air intakes,
other affected locations
use biocides, disinfectants, and sanitizers
with extreme caution and ensure that
occupant exposure is minimized
(Note: See discussion of duct cleaning in
Appendix B.)
Provide access to all the items that
must be cleaned, drained, or replaced
periodically
This blackish deposit was scraped from
a poorly maintained air handling unit
drain pan. The pan contained nutrients
caused by poor upstream filtration and
stagnant water that fostered the growth
of microbiological contaminants.
Mitigating IAQ Problems 91
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Problem #6:
HVAC System Distributes
Contaminants
Standing water on a roof can cause
water damage and potential mold
growth sites inside the building as well
as providing a breeding area for insects
and microbiologicals such as Legionella.
The outside air intake (near the far left of
this photograph) is located close to the
standing water and could be drawing in
insects and microbiological
contaminants.
Examples
Vnflltered air bypasses filters due to
problems
filter tracks are loose
poorly maintained filters sag when they
become overloaded with dirt
filters are the wrong size
Recirculation of air that contains dust or
other contaminants
m system recirculates air from rooms
containing pollutant sources
return air plenum draws air from rooms
that should be exhausted (e.g,, janitor's
closets)
return air plenums draw soil gases from
interiors of block corridor walls that
terminate above ceilings
Solutions
Modify air distribution system to
minimize recirculation of contaminants
provide local exhaust at point sources of
contaminants, adjust HVAC system to
provide adequate make-up air, and test to
verify performance
increase proportion of outdoor air
seal unplanned openings into return air
plenums and provide alternative local
ventilation (adjust HVAC system to
provide adequate make-up air and test to
verify performance)
Improve housekeeping) pest control,
occupant activities, and equipment use to
minimize release of contaminants from
all sources
Install improved filtration equipment to
remove contaminants
Check filter tracks for any gaps
92 Section?
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Problem f 7:
Non-HVAC Equipment is
a Source or Distribution
Mechanism for Contaminants
This discussion pertains to medium- to
large-scale pieces of equipment.
Examples
Non-HVAC equipment can produce
contaminants, as in the case of:
wet process copiers
large dry process copiers
engineering drawing reproduction
machines
It can also distribute contaminants, as in
the case of:
elevators, which can act as pistons and
draw contaminants from one floor to
another
Solutions
Install local exhaust near machines
{Note: Adjust HVAC system to provide
adequate make-up air, and test to verify
performance.)
Reschedule use to occur during periods of
low occupancy
Remove source
relocate occupants out of rooms
that contain contaminant-generating
equipment
relocate equipment into special use
areas equipped with effective exhaust
ventilation (test to verify control of air
pressure relationships)
Change air pressure relationships to
prevent contaminants from entering
elevator shaft
Sometimes there are unusual sources of
indoor air quality problems. An
inspection of the HVAC system revealed
air filters covered with a graphite dust
deposit from a broken elevator motor
generator. The motor generator was
repaired and corrections were made to
prevent the crossover of ventilation air
from the motor generator into the HVAC
mechanical room.
Mitigating IAQ Problems 93
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Problem #8:
Surface Contamination
Due to Poor Sanitation or
Accidents
The carpet on this floor was flooded
and an outbreak of humidifier fever
occurred. To eliminate microbiologicals,
the contaminated carpet was removed
and new carpet was installed.
Examples
Biological contaminants result in aller-
gies or other diseases
fungal, viral, bacterial (whole organisms
or spores)
bird, insect, or rodent parts or droppings,
hair, dander (in HVAC, crawlspace,
building shell, or near outdoor air
intakes)
Accidents
spills of water, beverages, cleansers,
paints, varnishes, mastics or specialized
products (printing, chemical art supplies)
fire damage: soot, odors, chemicals
Solutions
Clean
HVAC system components
some materials and furnishings (others
may have to be discarded)
(Note: Use biocides, disinfectants, and
sanitizers with caution and ensure that
occupant exposure is minimized.)
Remove sources of microbiological
contamination
water-damaged carpet, furnishings, or
building materials
Modify environment to prevent recur-
rence of microbiological growth
improve HVAC system maintenance
control humidity or surface temperatures
to prevent condensation
Provide access to all items that require
periodic maintenance
Use local exhaust where corrosive
materials are stored
Adjust HVAC system to provide adequate
make-up air, and test to verify perfor-
mance
94 Section?
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Problem #9:
Mold and Mildew Growth
Due to Moisture from
Condensation
Examples
Interior surfaces of walls near thermal
bridges
(e.g., uninsulated locations around struc-
tural members)
Carpeting on cold floors
Locations where high surface humidity
promotes condensation
Solutions:
Clean and disinfect to remove mold and
mildew
(Note: Follow up by taking actions to
prevent recurrence of microbiological
contamination. Use biocides, disinfec-
tants, and sanitizers with caution and
ensure that occupant exposure is mini-
mized.)
Increase surface temperatures to treat
locations that are subject to condensation
insulate thermal bridges
improve air distribution
Reduce moisture levels in locations that
are subject to condensation
repair leaks
increase ventilation (in cases where
outdoor air is cold and dry)
deaumidify (in cases where outdoor air
is warm and humid)
Dry carpet or other textiles promptly after
steam cleaning
(Note: Increase ventilation to accelerate
drying.)
Discard contaminated materials
This Is a school crawlspace in which
moisture should be controlled. The
fungus Is Fusarium, some species of
which are toxigenic and should not be
inside. The spores were distributed by
the air handler because the return
plenum was open to the crawlspace.
Mitigating IAQ Problems 95
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Problem #10:
Building Materials and
Furnishings Produce
Contaminants
Low levels of contaminants are emitted
from many of the building materials
and furnishings in an office. Dust can
accumulate on stacks of papers and
open shelves. Depending on how
they are cared for, plants potentially
add moisture, soil microbiologicals,
and pesticides.
Examples
Odors from newly installed carpets,
furniture, wall coverings
Newly drycleaned drapes or other textiles
Solutions
Remove source with appropriate cleaning
methods
steam clean carpeting and upholstery,
then dry quickly, ventilating to acceler-
ate the drying process
accept only fully dried, odorless
drycleaned products
Encapsulate source
seal surfaces of building materials that
emit formaldehyde
Reduce source
schedule installation of carpet, furniture,
and wall coverings to occur during
periods when the building is unoccupied
have supplier store new furnishings in a
clean, dry, well-ventilated area until
VOC outgassing has diminished
Increase outdoor air ventilation
total air supplied
proportion of fresh air
Remove the materials that are producing
the emissions and replace with lower
emission alternatives
(Note: Only limited information on
emissions from materials is available at
this tune. Purchasers can request that
suppliers provide emissions test data, but
should use caution in interpreting the test
results.)
96 Section?
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Problem #11:
Housekeeping or Maintenance
Activities Contribute to
Problems
Examples
Cleaning products emit chemicals, odors
Particulates become airborne during
cleaning (e-g.* sweeping, vacuuming)
Contaminants are released from painting,
caulking, lubricating
Frequency of maintenance is insufficient
to eliminate contaminants
Solutions
Remove source by modifying standard
procedures or frequency of maintenance
(Note: Changing procedures may require a
combination of policy-setting and training
in IAQ impacts of staff activities.)
improve storage practices
shift time of painting, cleaning, pest
control, other contaminant-producing
activities to avoid occupied periods
make maintenance easier by improving
access to filters, coils, and other compo-
nents
Reduce source
.select materials to minimize emissions of
contaminants while maintaining ad-
equate safety and efficacy
use portable HEPA ("high efficiency
particulate arrestance") vacuums vs. low-
efficiency paper-bag collectors
Use local exhaust
on a temporary basis to remove contami-
nants from work areas
as a permanent installation where
contaminants are stored
Indoor air quality problems pan b&
caused by lack of adequate house-
keeping practices. On the other hand,
deodorizers, cleansers and other
products can also produce odors and
contaminants.
Mitigating IAQ Problems 97
-------
Problem #12:
Specialized Use Areas as
Sources of Contaminants
This chemical storage room should be
maintained under negative pressure.
Properly designed and maintained local
exhaust will achieve the proper air
pressure relationship with surrounding
areas. Otherwise, such storage areas
can be a source of occupant exposure to
many airborne contaminants.
Examples
Food preparation
Art or print rooms
Laboratories
Solutions
Change pollutant pathway relationships
m run specialized use area under negative
pressure relative to surrounding areas
install local exhaust, adjust HVAC
system to provide make-up air, and test
to verify performance
Remove source by ceasing, relocating, or
rescheduling incompatible activities
Reduce source by selecting materials to
minimize emissions of contaminants
while maintaining adequate safety and
efficacy
Reduce source by using proper sealing
and storage for materials that emit
contaminants
98 Section?
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Problem #13:
Remodeling or Repair
Activities Produce Problems
Examples
Temporary activities produce odors and
contaminants
installation of new partieleboard,
partitions, carpet, or furnishings
painting
reroofing
demolition
Existing HVAC system does not provide
adequate ventilation for new occupancy
or arrangement of space
Solutions
Modify ventilation to prevent
rectrculation of contaminants
install temporary local exhaust in
work area, adjust HVAC system to
provide make-up air, and test to
verify performance
seal off returns in work area
close outdoor air damper during
re-roofing
Reduce source by scheduling work for
unoccupied periods and keeping ventila-
tion system in operation to remove odors
and contaminants
Reduce source by careful materials
selection and installation
select materials to minimize emissions
of contaminants while maintaining
adequate safety and efficacy
have supplier store new furnishings in a
clean, dry, well-ventilated area until
VOC outgassing has diminished
request installation procedures (e.g.,
adhesives) that limit emissions of
contaminants
Modify HVAC or wall partition layout if
necessary
partitions should not interrupt airflow
relocate supply and return diffusers
adjust supply and return air quantities
adjust total air and/or outdoor air supply
to serve new occupancy
Remodeling may involve
many activities that can
cause IAQ problems.
Ventilation modifications
can be used to isolate the
work area and prevent
pollutant build-up in
occupied spaces. Proper
storage practices can
minimize the release of
contaminants.
Mitigating IAQ Problems 99
-------
Problem #14:
Combustion Gases
Combustion odors can indicate the
existence of a serious problem. One
combustion product, carbon monoxide, is
an odorless gas. Carbon monoxide
poisoning can be life-threatening.
Air intakes are frequently located near
the loading dock for aesthetic reasons.
Unfortunately, this air intake placement
can draw car and truck exhaust into the
building, causing a variety of indoor air
quality complaints.
Examples
Vehicle exhaust
m offices above (or connected to) an
underground parking garage
rooms near (or connected by pathways
to) a loading dock or service garage
Combustion gases from equipment
(e.g., spillage from inadequately vented
appliances, cracked heat exchanger, re-
entrainment because local chimney is too
low)
areas near a mechanical room
distributed throughout zone or entire
building
Solutions
Seat to remove pollutant pathway
close openings between the contaminant
source and the occupied space
install well-sealed doors with automatic
closers between the contaminant source
and the occupied space
Remove source
m improve maintenance of combustion
equipment
modify venting or HVAC system to
prevent backdrafting
relocate holding area for vehicles at
loading dock, parking area
turn off engines of vehicles that are
waiting to be unloaded
Modify ventilation system
m install local exhaust in underground
parking garage (adjust HVAC system to
provide make-up air and test to verify
performance)
relocate fresh air intake (move away
from source of contaminants)
elevate chimney exhaust outlet
Modify pressure relationships
m pressurize spaces around area containing
source of combustion gases
10O Section?
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Problem #15:
Serious Building-Related
Illness
Some building-related illnesses can be life-
threatening. Even a single confirmed
diagnosis (which involves results from
specific medical tests) should provoke an
immediate and vigorous response,
Examples
Legionnaire's disease
(Note: If you suspect Legionnaire's
disease, call the local public health
department, check for obvious problem
sites, and take corrective action. There is
no way to be certain that a single case of
this disease is associated with building
occupancy; therefore, public health
agencies usually do not investigate single
cases. Watch for new cases.)
Hypersensitivity pneumonitis
(Note: Affected occupant(s) should be
removed and may not be able to return
unless the causative agent Is removed from
the affected person's environment.)
Solutions
Work with public health authorities
evacuation may be recommended or
required
Remove source
drain, clean, and decontaminate drip
pans, cooling towers, room unit air
conditioners, humidifiers, dehumidifiers,
and other habitats of Legionella, fungi,
and other organisms using appropriate
protective equipment
install drip pans that drain properly
provide access to all the items that must
be cleaned, drained, or replaced periodi-
cally
modify schedule and procedures for
improved maintenance
Discontinue processes that deposit
potentially contaminated moisture in air
distribution system
air washing
humidification
cease nighttime shutdown of air handlers
This air intake is located
between the cooling
towers. If the water in the
cooling towers becomes
contaminated with
Legionella, there is
potential for Legionnaire's
disease in the building.
Mitigating IAQ Problems 101
-------
The most economical
and successful
solutions to IAQ
problems are those
in which the operat-
ing principle of the
correction strategy
makes sense and is
suited to the problem.
JUDGING PROPOSED
MITIGATION DESIGNS
AND THEIR SUCESS
Mitigation efforts should be evaluated at
the planning stage by considering the
following criteria:
permanence
operating principle
degree to which the strategy fits the job
ability to institutionalize the solution
durability
installation and operating costs
conformity with codes
Permanence
Mitigation efforts that create permanent
solutions to indoor air problems are clearly
superior to those that provide temporary
solutions (unless the problems are also
temporary). Opening windows or running
'air handlers on full outdoor air may be
suitable mitigation strategies for a tempo-
rary problem such as outgassing of volatile
compounds from new furnishings, but
would not be good ways to deal with
emissions from a print shop. A permanent
solution to microbiological contamination
involves not only cleaning and disinfec-
tion, but also modification of the environ-
ment to prevent regrowth.
Operating Principle
The most economical and successful
solutions to IAQ problems are those in
which the operating principle of the
correction strategy makes sense and is
suited to the problem. If a specific point
source of contaminants has been identified,
treatment at the source (e.g., by removal,
sealing, or local exhaust) is almost always
a more appropriate correction strategy than
dilution of the contaminant by increased
general ventilation. If the IAQ problem is
caused by the introduction of outdoor air
that contains contaminants, increased
general ventilation will only make the
situation worse (unless the outdoor air is
cleaned).
Degree to Which the Strategy
Fits the Job
It is important to make sure that you
understand the IAQ problem well enough
to select a correction strategy whose size
and scope fit the job. If odors from a
special use area such as a kitchen are
causing complaints in a nearby office,
increasing the ventilation rate in the office
may not be a successful approach. The
mitigation strategy should address the
entire area affected.
If mechanical equipment is needed to
correct the IAQ problem, it must be
powerful enough to accomplish the task.
For example, a local exhaust system
should be strong enough and close enough
to the source so that none of the contami-
nant is drawn into nearby returns and
recirculated.
Ability to Institutionalize
the Solution
A mitigation strategy will be most success-
ful when it is institutionalized as part of
normal building operations. Solutions that
do not require exotic equipment are more
likely to be successful hi the long run than
approaches that involve unfamiliar
concepts or delicately maintained systems.
If maintenance or housekeeping proce-
dures or supplies must change as part of
the mitigation, it may be necessary to plan
for additional staff training, new inspection
checklists, or modified purchasing prac-
tices. Operating schedules for HVAC
equipment may also require modification.
Durability
IAQ mitigation strategies that are durable
and low-maintenance are more attractive to
owners and building staff than approaches
that require frequent adjustment or
102 Section?
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specialized maintenance skills. New items
of equipment should be quiet, energy-
efficient, and durable, so that the operators
are encouraged to keep them running.
Installation and Operating Costs
The approach with the lowest initial cost
may not be the least expensive over the
long run. Other economic considerations
include: energy costs for equipment opera-
tion; increased staff time for maintenance;
differential cost of alternative materials
and supplies; and higher hourly rates if
odor-producing activities (e.g., cleaning)
must be scheduled for unoccupied periods.
Although these costs will almost certainly
be less than the cost of letting the problem
continue, they are more readily identifi-
able, so an appropriate presentation to
management may be required.
Conformity with Codes
Any modification to building components
or mechanical systems should be designed
and installed in keeping with applicable
fire, electrical, and other building codes.
Judging the Success of a
Mitigation Effort
Two kinds of criteria can be used to judge
the success of an effort to correct an indoor
air problem:
reduced complaints
. measurement of properties of the indoor
air (often only of limited usefulness)
Reduction or elimination of complaints
appears to be a clear indication of success,
but that is not necessarily the case.
Occupants who see that their concerns are
being heard may temporarily stop report-
ing discomfort or health symptoms, even if
the actual cause of their complaints has not
been addressed. Lingering complaints may
also continue after successful mitigation if
people have become upset over the
MANAGING MITIGATION PROJECTS
INVOLVING SEVERE CONTAMINATION
Cautions
Elements
I Identify the extent of
-; contamination
Locating the original source of a
chemical release or microbiological
growth may only be the tip of the
iceberg. Pollutants often tend to
migrate through a building and collect
In "sinks", from which they can be
resuspended into the air. For ex-
ample, particles accumulate on \
horizontal surfaces that are not subject ;
to regular housekeeping; odors may 1
adsorb (stick) to porous materials.
Detailed surface and/or bulk sampling
may be needed to locate such "sec- '-':\,\
ondary" sources in order to solve an
air quality problem.
I Develop a precise scope of
work specifying exactly
^ how remediation will be
S performed
Depending on the problem, a detailed
knowledge of chemistry, microbiol-
ogy, building science, and health and
safety may be required.
^Monitor remediation to
5 ensure vvork practices are
"followed
Include air sampling along with
regular inspections if needed. Decon-
tamination of areas within an occu-
pied building is especially critical.
Conduct clearance
sampling
In the event of severe contamination,
representative air samples should be
collected to ensure that key indicators
have returned to background levels
and that the space can be safely
reoceupied.
Many routine IAQ problems can be
corrected by a common sense approach
not requiring special expertise. How-
ever, when complex exposure or
contamination Issues are involved, more
detailed technical assistance may be
needed for successful remediation.
Efforts such as those outlined above
are sometimes needed to deal with
severe contamination.
Mitigating IAQ Problems 103
-------
If you have made
several unsuccessful
efforts to control a
problem, then it may
be advisable to seek
outside assistance.
handling of the problem. Ongoing (but
reduced) complaints could also indicate
that there were multiple IAQ problems and
that one or more problems are still unre-
solved.
However, it can be very difficult to use
measurements of contaminant levels as a
means of determining whether air quality
has improved. Concentrations of indoor
air pollutants typically vary greatly over
time; further, the specific contaminant
measured may not be causing the problem.
If air samples are taken, readings taken
before and after mitigation should be
interpreted cautiously. It is important to
keep the "before" and "after" conditions as
identical as possible, except for the
operation of the control strategy. For
example, the same HVAC operation,
building occupancy and climatic condi-
tions should apply during both measure-
ment periods. "Worst-case" conditions
identified during the investigation should
be used.
Measurements of airflows, ventilation
rates, and air distribution patterns are the
more reliable methods of assessing the
results of control efforts. Airflow mea-
surements taken during the building
investigation can identify areas with poor
ventilation; later they can be used to
evaluate attempts to improve the ventila-
tion rate, distribution, or direction of flow.
Studying air distribution patterns will show
whether a mitigation strategy has success-
fully prevented a contaminant from being
transported by airflow.
Persistent Problems
Solving an indoor air quality problem is a
cyclical process of data collection and
hypothesis testing. Deeper and more
detailed investigation is needed to suggest
new hypotheses after any unsuccessful or
partially-successful control attempt.
Even the best-planned investigations
and mitigation actions may not produce a
resolution to the problem. You may have
made a careful investigation, found one or
more apparent causes for the problem, and
implemented a control system. Nonethe-
less, your correction strategy may not have
caused a noticeable reduction in the
concentration of the contaminant or
improvement in ventilation rates or
efficiency. Worse, the complaints may
persist even though you have been
successful at improving ventilation and
controlling all of the contaminants you
could identify. When you have pursued
source control options and have increased
ventilation rates and efficiency to the limits
of your expertise, you must decide how
important it is to pursue the problem
further.
If you have made several unsuccessful
efforts to control a problem, then it may be
advisable to seek outside assistance. The
problem is probably fairly complex, and it
may occur only intermittently or cross the
borders that divide traditional fields of
knowledge. It is even possible that poor
indoor air quality is not the actual cause of
the complaints. Bringing in a new
perspective at this point can be very
effective.
The next section provides guidance on
hiring professional indoor air quality
assistance. An interdisciplinary team (such
as people-with engineering and medical or
health backgrounds) may be needed to
solve particularly difficult problems.
1O4 Section?
-------
Hiring Professional Assistance to
Solve an SAQ Problem
M
I any IAQ problems are simple to
resolve when facility staff have been
educated about the investigation process,
to other cases, however, a time comes
when outside assistance is needed. Profes-
sional help might be necessary or desirable
in the following situations, among others;
Mistakes or delays could have serious
consequences (e,g., health hazards,
liability exposure, regulatory sanctions).
Building management feels that an inde-
pendent investigation would be better
received or more effectively documented
than an in-house investigation.
Investigation and mitigation efforts by
facility staff have, not relieved the
IAQ problem,
Preliminary findings by staff suggest the
need for measurements that require
specialized equipment and training
beyond in-house capabilities,
You may be able to find help by
looking in the yellow pages of your
telephone book (e,g., under "Engineers,"
"Environmental Services,"'"Laboratories -
Testing," or "Industrial Hygienists"),
Local or State health or air pollution
agencies may have lists of firms offering
IAQ services in your area. It may also be
useful to seek out referrals from other
building management firms.
Local, State, or Federal government
agencies may be able to provide expert
assistance or direction in solving IAQ
problems. It is particularly important to
contact your local or State Health
Department if you suspect that you have a
serious building-related illness potentially
linked to biological contamination in your
building.
If available government agencies do not
have personnel with the appropriate skills
to assist in solving your IAQ problem, they
may be able to direct you to firms in your
area with experience in indoor air quality
work. Note that even certified
professionals from disciplines closely
related to IAQ issues (such as industrial
hygienists, ventilation engineers, and
lexicologists) may not have the specific
expertise needed to investigate and resolve
indoor air problems. Individuals or groups
that offer services in this evolving field
should be questioned closely about their
related experience and their proposed
approach to your problem.
As with any hiring process, the better
you know your own needs, the easier it
wiU be to select a firm or individual to
service those needs. Firms and individuals
working in IAQ may come from a variety
of disciplines. Typically, the skills of
HVAC engineers and industrial hygienists
are useful for this type of investigation,
although input from other disciplines such
as chemistry, chemical engineering,
architecture, microbiology, or medicine
may also be important If problems other
than indoor air quality are involved,
experts in lighting, acoustic design, interior
design, psychology, or other fields may be
helpful in resolving occupant complaints
about the indoor environment.
MAKE SURE THAT THEIR
APPROACH FITS YOUR NEEDS
As you prepare to hire professional
services in the area of indoor air quality, be
aware it is a developing area of knowledge.
Most consultants working in the field
received their primary training in other
areas. A variety of investigative methods
may be employed, many of which are
ineffective for resolving any but the most
As you prepare to hire
professional services
in the area of indoor
air quality, be aware
that it is a developing
area of knowledge.
Hiring Professional Assistance to Solve an IAQ Problem 105
-------
Diagnostic outcomes
to avoid include an
evaluation that over-
emphasizes measur-
ing concentrations of
pollutants and a
report that links ail
the deficiencies in the
building to the
problem without
considering their
actual association
with the complaints.
obvious situations. Inappropriately designed
studies may lead to conclusions that are
either false negative (e.g., falsely con-
cludes that there is no problem associated
with the building) or false positive (e.g.,
incorrectty attributes the cause to building
conditions).
Diagnostic outcomes to avoid include;
an evaluation that overemphasizes
measuring concentrations of pollutants
and comparing those concentrations to
numerical standards, and
a report that lists a series of major and
minor building deficiencies and links all
the deficiencies to the problem without
considering their actual association with
the complaints
Considerable care should be exercised
when interviewing potential consultants to
avoid those subscribing to these strategies,
A qualified IAQ investigator should have
appropriate experience, demonstrate a
broad understanding of indoor air quality
problems and the conditions which can
lead to them, and use a phased diagnostic
approach.
SELECTION CRITERIA
Most of the criteria used in selecting a
professional to provide indoor air quality
services are similar to those used for other
professionals:
company experience in solving similar
problems, including training and
experience of the individuals who would
be responsible for the work
quality of interview and proposal
company reputation
knowledge of local codes and regional
climate conditions
cost
Experience
An EPA survey of firms providing IAQ
services found that almost half had been
providing IAQ diagnostic or mitigation
services in non-industrial settings for ten or
fewer years.
Ask how much IAQ work and what type
of IAQ work the firm has done,
Have the firm identify the personnel who
would be responsible for your case, tiheir
specific experience, and related
qualifications. Contract only for the
services of those individuals, or require
approval for substitutions.
Quality of Interview and
Proposal
Several guidelines may be of assistance in
hiring IAQ professionals,
/. Competent professionals will ask
questions about your situation to see
whether they feel they can offer services
that wUl assist you,
The causes arid potential remedies for
indoor air quality problems vary greatly.
A firm needs at least a preliminary
understanding of the facts about what is
going on in your building to evaluate if it
has access to the professional skills
necessary to address your concerns and to
make effective use of its personnel from
the outset. Often a multi-disciplinary team
of professionals is needed.
2. The proposal for the investigation
should emphasize observations rather
than measurements,
Section 6 describes the four types of
information that may need to be gathered
in an investigation in order to resolve an
indoor air quality problem; the occupant
complaints, the HVAC system, pollutant
pathways, and pollutant sources. There is
also a discussion of the role of monitoring
106 Sections
-------
within an investigation. Non-routine
measurements (such as relatively expen-
sive sampling for VOCs) should not be
provided without site-specific justification.
3. The staff responsible for building in-
vestigation should have a good under-
standing of the relationship between JAQ
and the building structure, mechanical
systems, and human activities.
For example, lack of adequate ventila-
tion is at least a contributing factor in
many indoor air quality problem situations.
Evaluating the performance of the ventila-
tion system depends on understanding the
interaction between the mechanical system
and the human activity within the building.
In some cases building investigators
may have accumulated a breadth of
knowledge. For example, a mechanical
engineer and an industrial hygienist see
buildings differently. However, a
mechanical engineer with several years of
experience in IAQ problem investigations
may have seen enough health-related
problems to cross the gap; likewise, an
industrial hygienist with years of
experience studying problems in an office
setting may have considerable expertise in
HVAC and other building mechanical
systems.
Either in the proposal or in discussion,
the consultant should:
Describe the goal(s), methodology, and
sequence of the investigation, the
information to be obtained, and the
process of hypothesis development and
testing, including criteria for decision-
making about further data-gathering.
The proposal should include an explana-
tion of the need for any proposed
measurements. The goal is to reach a
successful resolution of the complaints,
not simply to generate data.
Identify any elements of the work that
will require a time commitment from the
client's own staff, including information
to be collected by the client.
Identify additional tasks (and costs)
which are part of solving the IAQ
problem but are outside the scope of the
contract. Examples might include
medical examination of complainants,
laboratory fees, and contractor's fees for
mitigation work.
Describe the schedule, cost, and work
product(s), such as a written report,
specifications, and plans for mitigation
work; supervision of mitigation work;
and training program for building staff.
Discuss communication between the
IAQ professional and the client: How ,
often will the contractor discuss the
progress of the work with the client?
Who will be notified of test results and
other data? Will communications be in
writing, by telephone, or face-to-face?
Will the consultant meet with building
occupants to collect information? Will
the consultant meet with occupants to
discuss findings if requested to do so?
Reputation
There are no Federal regulations covering
professional services in the general field of
indoor air quality, although some disci-
plines (e.g., engineers, industrial hygien-
ists) whose practitioners work with IAQ
problems have licensing and certification
requirements.
Building owners and managers who
suspect that they may have a problem with
a specific pollutant (such as radon,
asbestos, or lead) may be able to obtain
assistance from local and State Health
Departments. Government agencies and
affected industries have developed training
programs for contractors who diagnose or
mitigate problems with these particular
contaminants.
Firms should be asked to provide refer-
ences from clients who have received
comparable services. In exploring refer-
The goal of the
investigative process
is to reach a success-
ful resolution of the
complaints, not
simply to generate
data.
Hiring Professional Assistance to Solve an IAQ Problem 107
-------
ences, it is useful to ask about long-term
follow-up. After the contract was com-
pleted, did the contractor remain in contact
with the client to ensure that problems did
not recur?
Knowledge of Local Codes and
Regional Climate Conditions
Familiarity with State and local regulations
and codes helps to avoid problems during
mitigation. For example, in making
changes to the HVAC system, it is
important to conform to local building
codes. Heating, cooling, and humidity
control needs are different in different
geographic regions, and can affect the
selection of an appropriate mitigation
approach. Getting assurances that all firms
under consideration have this knowledge
becomes particularly important if it
becomes necessary to seek expertise
from outside the local area.
Cost
It is impossible for this document to give
specific guidance on the cost of profes-
sional services. If projected costs jump
suddenly during the investigation process,
the consultants should be able to justify
that added cost.
The budget will be influenced by a
number of factors, including:
complexity of the problem
size and complexity of the building and
its HVAC system(s)
quality and extent of recordkeeping by
building staff and management
type of report or other product required
number of meetings required (formal
presentations can be quite expensive)
air sampling (e.g., use of instruments,
laboratory analysis) if required
108 Sections
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Appendix A;
Common 1AQ Measurements - A General G id
I he following is a brief introduction to
making measurements that might be
needed in the course of developing an IAQ
profile or investigating an IAQ complaint
Emphasis has placed on the param-
eters most commonly of interest in non-
research studies, highlighting the more
practical methods and noting some
inappropriate tests to avoid. Most of the
instruments discussed in this section are
relatively inexpensive and readily available
from many local safety supply companies,
Consult the guidance in Section 6 on pages
74-77 before determining whether to
proceed with air sampling.
OVERVIEW OF SAMPLING
DEVICES
Air contaminants of concern in IAQ ean be
measured by one or more of the following
methods:
Vacuum Pump:
A vacuum pump with a known airflow rate
draws air through collection devices, such
as a filter (catches airborne particles), a
sorbent tube (which attracts certain
chemical vapors to a powder such as
carbon), or an impinger (bubbles the
contaminants through a solution in a test
tube). Tests originated for industrial
environments typically need to be adjusted
to a lower detection limit for IAQ work.
Labs ean be asked to report when trace
levels of an identifiable contaminant are
present below the limit of quantification
and detection.
In adapting an industrial hygiene
sorbent tube sampling method for IAQ, the
investigator must consider at least two
important questions. First: are the
emissions to be measured from a product's
SELECTING MEASUREMENT DEVICES. ' ,
The growing Interest in indoor air quality Is stimulating the develop-
ment of instruments for IAQ research and building Investigations. As
"you evaluate the available measurement devices, it may be helpful to
consider the following criteria: : ,
;;iaseof.use . - . -... .:'... .'..."'..
portability
''(.'direct-reeding vs. analysis required
rUggedness ' ' ' .-.-.'.''. .-
time required for each measurement
"Quality assurance ':. ''.''..".. .''.'"..-..
if availability of service and customer support
: rrtaintenanee and calibration requirements
. . .. .
time-averaged vs. instantaneous readings
sensitivity ,
compatibility with computer or data logging accessories
[dost -.-.'/'' '' ".'
f single use only vs. reusable
purchase vs. rental . :
end use the same as those of concern
during manufacturing? Second: is it
necessary to increase the air volume
sampled? Such an increase may be needed
to detect the presence of contaminants at
the low concentrations usually found in
non-industrial settings. For example, an
investigator might have to increase
sampling time from 30 minutes to 5 hours
in order to detect a substance at the low
concentrations found during IAQ investi-
gations. In cases where standard sampling
methods are changed, qualified industrial
hygienists and chemists should be con-
sulted to ensure that accuracy and preci-
sion remain acceptable.
Direct-reading Meter:
Direct-reading meters estimate air concen-
trations through one of several detection
Common IAQ MeasurementsA General Guide 109
-------
Above: A smoke tube, which is one type
of chemical smoke device. Used to ob-
serve patterns of air movement and the
direction (negative or positive} of pres-
sure differences. Below: A microman-
ometer. Used for measuring pressure
differentials to learn about airflow. Pro-
vides quantitative data, as compared to
the qualitative information provided by
chemical smoke.
principles. These may report specific
chemicals (e.g., CO2 by infrared light),
chemical groups (e.g., certain volatile
organics by photoionization potential), or
broad pollutant categories (e.g., all respi-
rable particles by scattered light). Detec-
tion limits and averaging time developed
for industrial use may or may not be appro-
priate for IAQ.
Detector tube kit:
Detector tube kits generally include a hand
pump that draws a known volume of air
through a chemically treated tube intended
to react with certain contaminants. The
length of color stain resulting in the tube
correlates to chemical concentration.
Personal monitoring devices:
Personal monitoring devices (sometimes
referred to as "dosimeters") are carried of
worn by individuals and are used to mea-
sure that individual's exposure to particular
chemical(s). Devices that include a pump
are called "active" monitors; devices that
do not include a pump are called "passive"
monitors. Such devices are currently used
for research purposes. It is possible that
sometime in the future they may also be
helpful in IAQ investigations in public and
commercial buildings.
SIMPLE VENTILATION/COMFORT
INDICATIONS
Thermal Comfort: Temperature
and Relative Humidity
The sense of thermal comfort (or discom-
fort) results from an interaction between
temperature, relative humidity, air move-
ment, clothing, activity level, and indi-
vidual physiology. Temperature and
relative humidity measurements are
indicators of thermal comfort.
Methodology
Measurements can be made with a simple
thermometer and sling psychrometer or
with electronic sensors (e.g., a thermo-
hygrometer). Accuracy of within + or - 1ฐF
110 Appendix A
-------
is recommended for temperature measure-
ments. For each measurement, time should
be allowed for the reading to stabilize to
room conditions. Refer to the specifica-
tions for the measuring device; some take
several minutes to stabilize. Electronic
relative humidity (RH) meters must be
calibrated frequently.
Indoor relative humidity is influenced
by outdoor conditions. A single indoor
measurement may not be a good indication
of long-term relative humidity in the build-
ing. Programmable recording sensors can
be used to gain an'understanding of tem-
perature or humidity conditions as they
change over time.
Using the Results
Temperature and humidity directly affect-
thermal comfort. They rnay also provide
indirect indications of HVAC condition
and the potential for airborne contamina-
tion front biological or organic com-
pounds. There is considerable debate
among researchers, IAQ professionals, and
health professionals concerning recom-
mended levels of relative humidity; how-
ever, the humidity levels recommended by
different organizations generally range
between 30% and 60% RH.
Comparison of indoor and outdoor
temperature and humidity-readings taken
during complaint periods can indicate
whether thermal discomfort might be doe
to extreme conditions beyond the design
capacity of HVAC equipment or the build-
ing envelope, . . .
Measure next to thermostats to confirm
calibration. Measure at the location, of
complaints to evaluate whether or not
temperature and humidity at that location
are within the comfort zone (see Figure 6-2
on page 57.
Readings that show large variations
within the space may indicate a room air
distribution or mixing problem. Readings
that are highly variable over time may
indicate control or balance problems with
the HVAC systems.
Tracking Air Movement with
Chemical Smoke
Chemical smoke can be helpful in evaluat-
ing HVAC systems, tracking potential
contaminant movement, and identifying: .
pressure differentials.- Chemical smoke - -
moves, from areas of higher pressure to ':
of lower pressure if is an,
opening between them-(e.g., door, utility
penetration).''Because it is'heatles^, '. -
chemical smoke is extremely sensitive to'
air currents. Investigators can -about
airflow; patterns by observing the direction'
and speed of smoke movement Puffs of
smoke'released at the shell of the building
(by doors, windows, or gaps) will indicate
whether the HVAC are maintain-;
ing interior spaces under positive pressure
relative to the outdoors. -
Methodology
Chemical smoke is available with various
dispensing mechanisms, including'smoke
"bottles," "guns," "pencils," or "tubes."
The dispensers allow smoke to be released
in controlled quantities and directed" at '
specific locations. It is often more
informative to use a number of small puffs
of smoke as you move along an air
A psychrometer. Used to
measure dry bulb and wet
bulb temperatures and to
determine relative humidity.
based upon a psychometric
chart, The NIOSH protocol
for indoor air investigations
always includes measure-
ment of indoor and outdoor
relative humidity. There are
two types of psychrometers:
aspirated (with a fanl or
sling (without a fan).
'Common IAQ Measurements -A General Guide 111
-------
pathway rather than releasing a large
amount in a single puff. (Note: Avoid
direct inhalation of chemical smoke,
because it can be irritating. Do not release
smoke directly on smoke detectors.)
Using the Results
Smoke released mid-room: Observation
of a few puffs of smoke released in mid-
room or mid-cubicle can help to visualize
air circulation within the space. Dispersal
of smoke in several seconds suggests good
air circulation, while smoke that stays
essentially still for several seconds
suggests poor circulation. Poor air
circulation may contribute to sick building
syndrome complaints or may contribute to
comfort complaints even if there is
sufficient overall air exchange.
Smoke released near diffusers, grilles:
Puffs of smoke released near HVAC vents
give a general idea of airflow. (Is it in or
out? Vigorous? Sluggish? No flow?)
This is helpful in evaluating the supply and
return system and determining whether
ventilation air actually reaches the breath-
ing zone. (For a variable air volume
system, be sure to take into account how
the system is designed to modulate. It
could be on during the test, but off for
much of the rest of the day.) "Short-
circuiting" occurs when air moves
relatively directly from supply diffusers to
return grilles, instead of mixing with room
ah- in the breathing zone. When a substan-
tial amount of air short-circuits, occupants
may not receive adequate supplies of
outdoor air and source emissions may not
be diluted sufficiently.
Carbon Dioxide (CO2) as an
Indicator of Ventilation
CO2 is a normal constituent of the atmo-
sphere. Exhaled breath from building
occupants is an important indoor CO2
source. Indoor CO2 concentrations can,
under some test conditions, provide a good
indication of the adequacy of ventilation.
Comparison of peak CO2 readings between
rooms, between air handler zones, and at
varying heights above the floor, may help
to identify and diagnose various building
ventilation deficiencies.
Methodology
CO2 can be measured with either a direct-
reading meter or a detector tube kit. The
relative occupancy, air damper settings,
and weather should be noted for each
period of CO2 testing.
CO2 measurements for ventilation
should be collected away from any source
that could directly influence the reading
(e.g., hold the sampling device away from
exhaled breath). Individual measurements
should be short-term. As with many other
measurements of indoor air conditions, it is
advisable to take one or more readings in
"control" locations to serve as baselines for
comparison. Readings from outdoors and
from areas in which there are no apparent
IAQ problems are frequently used as
controls. Outdoor samples should be taken
near the outdoor air intake.
Measurements taken to evaluate the
adequacy of ventilation should be made
when concentrations are expected to peak.
It may be helpful to compare measure-
ments taken at different times of day. If
the occupant population is fairly stable
during normal business hours, CO2 levels
will typically rise during the morning, fall
during the lunch period, then rise again,
reaching a peak in mid-afternoon. In this
case, sampling in the mid- to late-after-
noon is recommended. Other sampling
times may be necessary for different
occupancy schedules.
Using the Results
Peak CO2 concentrations above 1000 ppm
in the breathing zone indicate ventilation
problems. Carbon dioxide concentrations
below 1000 ppm generally indicate that
ventilation is adequate to deal with the
112 Appendix A
-------
routine products of human occupancy.
However, there are several reasons not to
conclude too quickly that a low CO2
reading means no IAQ problem exists.
Problems can occur in buildings in which
measured CO2 concentrations are below
1000 ppm. Although CO2 readings
indicate good ventilation, for example, if
strong contaminant sources are present,
some sort of source control may be needed
to prevent IAQ problems. Errors in
measurement and varying CQ2 concentra-
tions over time can also cause low readings
that may be misleading.
Elevated CO2 may be due to various
causes alone or in combination, such as:
increased occupant population, air ex-
change rates below ASHRAE guidelines,
poor air distribution, and poor air mixing.
A higher average CO2 concentration in the
general breathing zone (at least two feet
from exhaled breath) than in the air
entering return grilles is an indication of
poor air mixing. Smoke tubes and
temperature profiles will help to clarify air
circulation patterns.
If CO2 measurements taken before the
occupied period begins are higher than
outdoor readings taken at the same time,
there may be an operating problem with
the HVAC system. Potential problems
include the following:
ventilation terminated too early the
evening before (as compared with the
occupancy load on the space)
combustion by-products from a nearby
roadway or parking garage are drawn
into the building
a gas-fired heating appliance in the
building has a cracked heat exchanger
Outdoor CO2 concentrations above 400
ppm may indicate an outdoor contamina-
tion problem from traffic or other combus-
tion sources. Note, however, that detector
tubes cannot provide accurate measure-
ments of CO2 in hot or cold weather.
Measuring Airflow
Measurements of airflow allow investiga-
tors to estimate the amount of outdoor air
that is entering the building and to evaluate
HVAC system operation. The most
appropriate measurement technique
depends on the characteristics of the
measurement location.
Methodology
Airflow quantities can be calculated by
measuring the velocity and cross-sectional
area of the airstream. For example, if air is
A flow hood. Used to
measure the total air flow
(outdoor plus recirculated
air) from a diffuser.
Common IAQ MeasurementsA General Guide 113
-------
L
A vacuum pump with
attachments for sampling
with a filter, a sorb&nt tube,
and an impinger. Use In a
non'tndustrial setting may
require a larger volume of
air. Consult with qualified
Industrial hygienfsts and
shsffilsts if adapting
sampling methods.
moving at 100 feet per minute in a 24" x
12" duct, the airflow is:
100 feetlminute x2 square feet duct
= 200 cubic feet/minute
Air velocity can be measured with a pilot
tube or anemometer. Air velocity within
an airstreara is likely to vary considerably.
For example, it is extremely difficult to
measure air velocity at supply diffusers
because of turbulence around the mixing
vanes. The best estimates of air velocity
can be achieved by averaging the results of
a number of measurements, ASTM
Standard Practice D 3154 provides
guidance on making such measurements.
This method is available from ASTM.
(See Appendix G for ASTM's address and
phone number,) The cross-sectional area
of the airstream is sometimes easy to
calculate (e.g., in a straight run of rectan-
gular ductwork), but can be very compli-
cated at other locations such as mixing
boxes or diffusers.
How hoods can be used for direct
measurement of airflows at locations such
as grilles, diffusers, and exhaust outlets.
They are not designed for use in ductwork.
Using the Results
Airflow measurements can be used to
determine whether the HVAC is
operating according to design and to
identify potential problem locations.
Building investigations often include
measurements of outdoor air quantities,
exhaust air quantities, and airflows at
supply diffusers and return' grilles.
Estimating Outdoor Mr
Quantities
Outdoor air quantities can be evaluated by
measuring airflow dkecfly. Investigators
often estimate the proportion of outdoor air
quantities using techniques such as thermal
mass balance (temperature) or CO2
measurements. Estimation of outdoor air
quantity using temperature measurements
is referred to as "thermal balance" or
sometimes "thermal mass balance."
Thermal Balance: Methodology
Use of this test requires the following
conditions:
1. Airstreams representing return air,
outdoor air, and mixed air (supply air
before it has been heated or cooled) are
accessible for separate measurement.
Some are already equipped with
an averaging thermometer that is strung
diagonally across the mixed air chamber,
the temperature is read out continuously on
an instrument panel. Some read out
supply, return, outdoor, and/or mixed air
temperature.
2. There is at least a several degree
temperature difference between the
building interior and the outdoor air.
3. Total air flow in the air handling system
can be estimated by using recent
balancing reports or pitot tube measure-
in ductwork. As an alternative, the
supply air at each diffuser can be estimated
(e.g., using a flow measuring hood), and
the results can be summed to calculate
total system air flow.
Temperature measurements can be made
with a simple thermometer or an electronic
114 Appendix A
-------
sensor. Several measurements should be
taken across each airstream and averaged.
It is generally easy to obtain a good tem-
perature reading in the outdoor air and
return airstreams. To obtain a good aver-
age temperature reading of the mixed air-
stream, a large number of measurements
must be taken upstream of the point at
which the airstream is heated or cooled.
This may be difficult or impossible in
some systems.
The percentage or quantity of outdoor air
is calculated using thermal measurements
as shown to the right
Methodology: Carbon Dioxide
Measurements
CO2 readings can be taken at supply outlets
or air handlers to estimate the percentage
of outdoor air in the supply airstream. The
percentage or quantity of outdoor air is cal-
culated using CO2 measurements as shown
to the right.
Using the Results
The results of this calculation can be
compared to the building design specifica-
tions, applicable building codes, or
ventilation recommendations such as
ASHRAE 62-1989 (see page 136 in
Appendix B) to see whether under-
ventilation appears to be a problem.
AIR CONTAMINANT
CONCENTRATIONS
Volatile Organic Compounds
(VOCs)
Hundreds of organic (carbon-containing)
chemicals are found in indoor air at trace
levels. VOCs may present an IAQ
problem when individual organics or
mixtures exceed normal background
concentrations.
ESTIMATING OUTDOOR AIR QUANTITIES
I Thermal Mass Balance
: Using'
LJOutdoor air percent) - :^return air .ImlX9d air x100
-".'- return air- outdoor air
y. T = temperature (degrees Farenheit)
Where:
Using Carbon Dioxide Measurements
" '
. .
Outdoor air (percent) =
-- ' .. . -
x 100
..
Where: 'Cg = ppm CO2 in the supply air (If measured in a room), or
Cs = ppm of C02 in the mixed air (if measured at an air
handler)
CR = ppm of CO2 in the return air
C0 = ppm of CO2 in the outdoor air
';.... : (AH these concentrations must be measured, not assumed.)
Converting Percent To CFM
Outdoor air (percent)
Outdoor air (cf m) =
100
x total airflow (cfm)
Where; cfm = cubic feet per minute
The number used for total airflow may be the air quantity supplied to
a room or zone, the capacity of an air handier, or the total airflow of
the HVAC system. /Vote; The actual amount of airflow In an air
handler is often different from the quantity in design documents.
Methodology: Total Volatile Organic
Compounds (TVOCs)
Several direct-reading instruments are
available that provide a low sensitivity
"total" reading for different types of
organics. Such estimates are usually
presented in parts per million and are
calculated with the assumption that all
chemicals detected are the same as the one
used-to calibrate the instrument. A
photoionization detector is an example of a
direct-reading instrument used as a
screening tool for measuring TVOCs.
A laboratory analysis of a sorbent tube
can provide an estimate of total solvents in
Common IAQ MeasurementsA General Guide 115
-------
the air. Although methods in this category
report "total volatile organic compounds"
(TVOCs) or "total hydrocarbons" (THC),
analytical techniques differ in their
sensitivity to the different types of organ-
ics. (For discussion of measurement
devices and their sensitivity, see Overview
of Sampling Devices on page 109.)
Using the Results
Different measurement methods are useful
for different purposes, but their results
should generally not be compared to each
other. Direct-reading instruments do not
provide sufficient sensitivity to differenti-
ate normal from problematic mixtures of
organics. However, instantaneous readouts
may help to identify "hot spots," sources,
and pathways. TVOCs or THC deter-
mined from sorbent tubes provide more
accurate average readings, but are unable
to distinguish peak exposures. A direct-
reading instrument can identify peak
exposures if they happen to occur during
the measurement period.
Methodology: Individual Volatile
Organic Compounds (VOCs)
High concentrations of individual volatile
organic compounds (VOCs) may also
cause IAQ problems. Individual VOCs
can be measured in indoor air with a
moderate degree of sensitivity (i.e.,
measurement in parts per million) through
adaptations of existing industrial air
monitoring technology. Examples of
medium sensitivity testing devices include
XAD-4 sorbent tubes (for nicotine),
charcoal tubes (for solvents), and
chromosorb tubes (for pesticides). After a
sufficient volume of air is pumped through
these tubes, they are sent to a lab for
extraction and analysis by gas
chromatography. Variations use a passive
dosimeter (charcoal badge) to collect the
sample or a portable gas chromatograph
onsite for direct injection of building air.
These methods may not be sensitive
enough to detect many trace level organics
present in building air.
High sensitivity techniques have
recently become available to measure
"trace organics" VOCs in the air (i.e.
measurements in parts per billion.)
Sampling may involve Tenax and multiple
sorbent tubes, charcoal tubes, evacuated
canisters, and other technology. Analysis
involves gas chromatography followed by
mass spectroscopy.
Using the Results
Guidelines for public health exposure (as
opposed to occupational exposure) for a
few VOCs are available in the World
Health Organization (WHO) Air Quality
Guidelines for Europe. These guidelines
address noncarcinogenic and carcinogenic
effects. Occupational exposure standards
exist for many other VOCs. No rule-of-
thumb safety factor for applying these
occupational limits to general IAQ is
currently endorsed by EPA and NIOSH.
Measurement of trace organics may
identify the presence of dozens to hundreds
of trace VOCs whose significance is
difficult to determine. It may be helpful to
compare levels in complaint areas to levels
in outdoor air or non-complaint areas.
Formaldehyde
Formaldehyde is a VOC that has been
studied extensively. Small amounts of
formaldehyde are present in most indoor
environments. Itching of the eyes, nose, or
throat may indicate an elevated concentra-
tion. Sampling may be helpful when
relatively new suspect materials are
present.
Methodology
A number of measurement methods are
available. Sensitivity and sampling time
are very important issues in selecting a
method; however, many methods allow
detection of concentrations well below
116 Appendix A
-------
0.1 ppm (see Using the Results below).
Measurement of short-term peaks (around
a two-hour sample time) is ideal for
evaluating acute irritation. Dosimeters
may accurately record long-term exposure
but may miss these peaks.
Two commonly used methods that are
generally acceptable for IAQ screening
involve impingers and sorbent tubes.
Other appropriate methods are also
available.
Using the Results
Various guidelines and standards are
available for formaldehyde exposure.
Several organizations have adopted
0.1 ppm as guidance that provides
reasonable protection against irritational
effects in the normal population.
Hypersensitivity reactions may occur at
lower levels of exposure. Worst-case .
conditions are created by mMnium .
ventilation, maximum temperatures, and.
high source loadings.
Biological Contaminants
Human health can be affected by exposure
to both living and non-living biological
contaminants. The term "bioaerosols**
describes airborne material that is or was
living, such as mold and bacteria, parts of
living organisms (e.g., insect body parts),
and animal feces.
Testing for biological contaminants
should generally be limited to:
cases where a walkthrough investigation
or human profile study suggests micro-
biological involvement
cases in which no other pollutant or
physical condition can account for
symptoms
Methodology
Inspection of building sanitary conditions
is generally preferred over sampling,
because direct sampling can produce
misleading results. Any sampling should
be accompanied by observations of
sanitary conditions and a determination as
to whether any health problems appear
likely to be related to biological contami-
nation.
No single technique is effective for
sampling the many biological contami-
nants found in indoor environments. A
variety of specific approaches are used to
retrieve, enumerate, and identify each kind
of microorganism from water, surfaces,
and air. Other specific methods are used
for materials such as feces or insect parts.
The utility of techniques depends
upon their use by professionals who have a
thorough understanding of the sample site
.and the target organism,
Where air sampling is desired, several
approaches are available. The most
common type of air sampler uses a pump
to pull air across a nutrient agar, which is
then incubated. Any bacterial or fungal
colonies that subsequently grow can be
counted and identified by a qualified
microbiologist. Different types of agar and
incubation temperatures are used to culture
different types of organisms. Only living '
organisms or spores in the air are counted
by this method. Settling plates, which are
simply opened to room ak and then
incubated, are sometimes used to identify
which bioaerosols are present in different
A viable impactor. Used to
sample for biologlcals.
Training is required in order
to analyze the results.
Common IAQ MeasurementsA General Guide 117
-------
High-flow indoor paniculate
sampler. Used to measure
particles 10 microns and
smaller that are readily
inhaled.
locations. The drawbacks to this technique
are that it does not indicate the quantity of
bioaerosols present and that only the
bioaerosols that are heavy enough to fall
out onto the agar will be recorded.
Using the Results
Quantities and types of bioaerosols can
vary greatly over time hi any given
building, making sampling results difficult
to interpret. Comparison of relative
numbers and types between indoors and
outdoors or between complaint areas and
background sites can help to establish
trends; however, no tolerance levels or
absolute guidelines have been established.
Low bioaerosol results by themselves are
not considered proof that a problem does
not exist, for a variety of reasons:
the sampling and identification tech-
niques used may not be suited to the
type(s) of bioaerosols that are present
biological growth may have been
inactive during the sampling period
the analysis technique used may not
reveal non-living bioaerosols (e.g., feces,
animal parts) that can cause health
reactions
Airborne Dust
Particles and fibers suspended in the air
generally represent a harmless background
but can become a nuisance or cause serious
health problems under some conditions.
Methodology
A variety of collection and analytical
techniques are available. Dust can be
collected by using a pump to draw air
through a filter. The filter can then be
weighed (gravimetric analysis) or exam-
ined under a microscope. Direct readouts
of airborne dust are also available (such as
using meters such as those equipped with a
"scattered light" detector).
Using the Results
IAQ measurements for airborne dust will
be well below occupational and ambient
air guidelines except under the most
extreme conditions. Unusual types or
elevated amounts of particles or fibers can
help identify potential exposure problems.
Combustion Products
Combustion products are released by
motor vehicle exhaust, tobacco smoke, and
other sources, and contain airborne dust
(see the previous section) along with
potentially harmful gases such as carbon
monoxide and nitrogen oxides.
Methodology
Direct-reading meters, detector tubes, and
passive dosimeters are among the tech-
niques most commonly used to measure
carbon monoxide and nitrogen oxides.
118 Appendix A
-------
Using the Results
Comparison with occupational standards
will reveal only whether an imminent
danger exists. Any readings that are
elevated above outdoor concentrations or
background building levels may indicate a
mixture of potentially irritating combustion
products, especially if susceptible indi-
viduals are exposed.
Other Inorganic Gases
Although they are not routinely sampled in
most IAQ studies, a variety of other gases
may be evaluated where conditions
warrant. Examples might include ammo-
nia, ozone, and mercury.
Methodology
EPA, NIOSH, and ASTM references
should be consulted for specific sampling
techniques. Detector tubes or impinger
methods are applicable in some cases.
Using the Results
No generalization'ean be applied to this
diverse group of substances.
Common IAQ MeasurementsA General Guide 119
-------
Page Intentionally Blank
-------
Appendix B:
HVAC Systems and Indoor Air Quality
I his appendix provides information
about specific HVAC system designs and
components in relation to indoor air
quality. It also serves as introductory
material for building owners and managers
who may be unfamiliar with the terminol-
ogy and concepts associated with HVAC
(heating, ventilating, and air conditioning)
system design. Further detailed informa-
tion can be found in ASHRAE manuals
and guides and in some of the guidance
developed by other trade and professional
associations. (See Guidelines of Care
Developed by Trade Associations in
Section 5.) Additional information can be
obtained using Appendix G or through
discussion with your facility engineer.
BACKGROUND
All occupied buildings require a supply of
outdoor air. Depending on outdoor
conditions, the air may need to be heated
or cooled before it is distributed into the
occupied space. As outdoor air is drawn
into the building, indoor air is exhausted or
allowed to escape (passive relief), thus
removing air contaminants.
The term "HVAC system" is used to
refer to the equipment that can provide
heating, cooling, filtered outdoor air, and
humidity control to maintain comfort
conditions in a building. Not all HVAC
systems are designed to accomplish all
of these functions. Some buildings rely
only on natural ventilation. Others lack
mechanical cooling equipment (AC), and
many function with little or no humidity
control. The features of the HVAC system
in a given building will depend on several
variables, including:
age of the design
climate
building codes in effect at the time of
the design
budget that was available for the project
planned use of the building
owners' and designers' individual
preferences
subsequent modifications
HVAC systems range in complexity
from stand-alone units that serve
individual rooms to large, centrally
controlled systems serving multiple zones
in a building. In large modern office
buildings with heat gains from lighting,
people, and equipment, interior spaces
often require year-round cooling. Rooms
at the perimeter of the same building (i.e.,
rooms with exterior walls, floors, or roof
surfaces) may need to be heated and/or
cooled as hourly or daily outdoor weather
conditions change. In buildings over one
story in height, perimeter areas at the lower
levels also tend to experience the greatest
uncontrolled air infiltration.
Working with the electrical
components of an HVAC
system involves the risk of
electrocution and fire. A
knowledgeable member of
the building staff should
oversee the inspection of
the HVAC controls.
HVAC Systems and Indoor Air Quality 121
-------
Some buildings use only natural
ventilation or exhaust fans to remove odors
and contaminants. In these buildings,
thermal discomfort and unacceptable
indoor air quality are particularly likely
when occupants keep the windows closed
because of extreme hot or cold tempera-
tures. Problems related to underventilation
are also likely when infiltration forces are
weakest (i.e., during the "swing seasons"
and summer months).
Modern public and commercial build-
ings generally use mechanical ventilation
systems to introduce outdoor air during the
occupied mode. Thermal comfort is
commonly maintained by mechanically
distributing conditioned (heated or cooled)
air throughout the building. In some
designs, air systems are supplemented by
piping systems that carry steam or water to
the building perimeter zones. As this
document is concerned with HVAC
systems in relation to indoor air quality,
the remainder of this discussion will focus
on systems that distribute conditioned au-
to maintain occupant comfort.
Roles of the HVAC System
Operator and Facility Manager
The system operator(s) and facility
manager(s) (or IAQ manager) are among
the most significant factors in determining
whether IAQ problems will occur in a
properly designed, constructed, and
commissioned HVAC system. HVAC
systems require preventive maintenance and
prompt repairs if they are to operate
correctly and provide comfortable condi-
tions. The operator(s) must have an
adequate understanding of the overall
system design and its limitations. The
HVAC system capacity and distribution
characteristics should be evaluated before
renovations to the building, changes in its
occupancy, or changes in the use of an area.
System operators must be able to
respond appropriately to occupant com-
plaints. For example, if an occupant
complains that it is too cold or too hot and
the'observed (measured) conditions are
outside of the ASHRAE comfort zone,
then the HVAC system needs to be
evaluated. Sometimes the problem can be
relieved by fine tuning or repairing the
HVAC system, but in some cases the
system cannot perform as expected, and a
long-term solution must be investigated.
TYPES OF HVAC SYSTEMS
Single Zone
A single ah- handling unit can only serve
more than one building area if the areas
served have similar heating, cooling, and
ventilation requirements, or if the control
system compensates for differences in
heating, cooling, and ventilation needs
among the spaces served. Areas regulated
by a common control (e.g., a single
thermostat) are referred to as zones.
Thermal comfort problems can result if the
design does not adequately account for
differences in heating and cooling loads
between rooms that are in the same zone.
This can easily occur if:
The cooling load in some area(s) with-
in a zone changes due to an increased
occupant population, increased lighting,
or the introduction of new heat-produc-
ing equipment (e.g., computers, copiers).
Areas within a zone have different solar
exposures. This can produce radiant heat
gains and losses that, in turn, create
unevenly distributed heating or cooling
needs (e.g., as the sun angle changes
daily and seasonally).
Multiple Zone
Multiple zone systems can provide each
zone with air at a different temperature by
heating or cooling the airstream in each
zone. Alternative design strategies involve
delivering air at a constant temperature
while varying the volume of airflow, or
modulating room temperature with a
122 Appendix B
-------
supplementary system (e.g., perimeter hot
water piping).
Constant Volume
Constant volume systems, as their name
suggests, generally deliver a constant
airflow to each space. Changes in space
temperatures are made by heating or
cooling the air or switching the air han-
dling unit on and off, not by modulating
the volume of air supplied. These systems
often operate with a fixed minimum
percentage of outdoor air or with an "air
economizer" feature (described in the
Outdoor Air Control discussion that
follows).
Variable Air Volume
Variable air volume systems maintain
thermal comfort by varying the amount of
heated or cooled air delivered to each
space, rather than by changing the air
temperature. (However, many VAV
systems also have provisions for resetting
the temperature of the delivery air on a
seasonal basis, depending on the severity
of the weather). Overcooling or
overheating can .occur within a given zone
if the system is not adjusted to respond to
the load. Underventilation frequently
occurs if the system is not arranged to
introduce at least a minimum quantity (as
opposed to percentage) of outdoor air as
the VAV system throttles back from full
airflow, or if the system supply air
temperature is set too low for the loads
present in the zone.
BASIC COMPONENTS OF AN
HVAC SYSTEM
The basic components of an HVAC system
that delivers conditioned air to maintain
thermal comfort and indoor air quality are:
outdoor air intake
mixed-air plenum and outdoor air control
air filter
heating and cooling coils
humidification and/or de-humidification
equipment
TESTING AND BALANCING
'
. Modern HVAC systems typically use sophisticated, automatic controls
...to supply the proper amounts of air for heating, cooling, and ventila-
v tion in commercial buildings. Problems during installation, operation,
Sjnaintenance, and servicing of the HVAC system could prevent it from
^operating as designed. Each system should be tested to ensure its
* initial and continued performance. In addition to providing acceptable
^thermal conditions and ventilation air, a properly adjusted and
^balanced system can also reduce operating costs and increase
^equipment life.
Testing and balancing involves the testing, adjusting, and faalanc-
e, ing of HVAC system components so that the entire system provides
^airflows that are in accordance with the design specifications. Typical
^components and system parameters tested include:
Tall supply, return, exhaust, and outdoor airflow rates
" control settings and operation
^TTajr temperatures ": ..;'.
,ป fan speeds and power consumption-'-.
? filter or collector resistance
* The typical test and balance agency or contractor coordinates with
_ the control contractor to accomplish three goals: verify and ensure
.Jthe most effective system operation within the ctesign specifications,
^Jdentify and correct any problems, and ensure the safety of the
system. '''"/ *"'_:'"" -.-"";':'- .--...-- '';"- .' :: ' . . . .
A test and balance report should provide a complete record of the
fc design, preliminary measurements, and finaltest data. The report
should Include any discrepancies between the test data and the
^design specifications, along with reasons for those discrepancies. To
* facilitate future performance checks and adjustments, appropriate
^records should;be kept on jail damper positions, equipment capacities,
s control types and locations, control settings and operating logic,
>*jiirflow rates, static pressures, fan speeds, and horsepowers.
T"~* Testing and balancing of existing building systems should be
" performed whenever there is reason to believe the system is not
^-functioning as designed or when current records do not accurately
reflect the actual operation of the system, the Associated Air Balance
r Council recommends the following guidelines in determining whether
^testing and balancing is required: "
ji"When space has been renovated or changed to provide for new
a, occupancy. ;
, When HVAC equipment has been replaced or modified.
When control settings have been readjusted by maintenance or
other personnel.
After the air conveyance system has been cleaned.
When accurate records are required to conduct an IAQ investigation.
"When the building owner is unable to obtain design documents or
*** appropriate air;exchange rates for compliance with IAQ standards or
i "guidelines.
Because of the diversity of system types and the interrelationship
. of system components, effective balancing requires a skilled techni-
f cian with the proper experience and instruments. Due to the nature of
^the work, which involves the detection and remediation of problems,
* it is recommended that an independent test and balance contractor be
used and that this contractor report directly to the building owner,
" facility manager, or IAQ manager.
HVAC Systems and Indoor Air Quality 123
-------
FIGURE B-1: Typical HVAC System Components
-Freeze Stat
Mixed Air Stat
Cooling Coil and Drip Pan
Courtesy of Terry Brennan,
Csmroden Associates,
Orlskany, NY
m supply fan
ducts
terminal device
return air system
exhaust or relief fans and air outlet
self-contained heating or cooling unit
control
boiler
cooling tower
water chiller
The following discussion of these
components (each of which may occur
more than once in any total HVAC system)
emphasizes features that affect indoor air
quality. It may be helpful to refer to this
section when using the HVAC Checklists.
The illustration above shows the
general relationship between many of
these components; however, many
variations are possible.
Outdoor Air Intake
Building codes require the introduction of
outdoor air for ventilation in most build-
ings. Most non-residential air handlers are
designed with an outdoor air intake on the
return side of the ductwork. Outdoor air
introduced through the air handler can be
filtered and conditioned (heated or cooled)
before distribution. Other designs may
introduce outdoor air through air-to-air
heat exchangers and operable windows.
124 Appendix B
-------
Indoor air quality problems can be
produced when contaminants enter a
building with the outdoor air. Rooftop or
wall-mounted air intakes are sometimes
located adjacent to or downwind of
building exhaust outlets or other contami-
nant sources. Problems can also result if
debris (e,g., bird droppings) accumulates at
the intake, obstructing airflow and poten-
tially introducing microbiological contami-
nants.
If more air is exhausted than is
introduced through the outdoor air intake,
then outdoor air will enter the building at
any leakage sites in the shell. Indoor air
quality problems can occur if the leakage
site is a door to a loading dock, parking
garage, or some other area associated with
pollutants,
Mixed-Air Plenum and Outdoor
Air Controls
Outdoor air is mixed with return air (air
that has already circulated through the
HVAC system) in the mixed-air plenum of
an air handling unit. Indoor air quality
problems frequently result if the outdoor
air damper is not operating properly (e.g.,
if the system is not designed or adjusted to
allow the introduction of sufficient outdoor
air for the current use of the building). The
amount of outdoor air introduced in the
occupied mode should be sufficient to
meet needs for ventilation and exhaust
make-up. It may be fixed at a constant
volume or may vary with the outdoor
temperature.
When dampers that regulate the flow of
outdoor air are arranged to modulate, they
are usually designed to bring in a mini-
mum amount of outdoor air (in the
occupied mode) under extreme outdoor
temperature-conditions and to open as
outdoor temperatures approach the desired
indoor temperature. Systems that use
outdoor air for cooling are called "air
economizer cooling" systems. Air
economizer systems have a mixed air
Above: The air intake in the background
is located too close to the sanitary vents
{the straight pipes to the left and in the
center foreground) and the bathroom
exhaust vent (next to the sanitary vent
on the right side). Beiow: The return air
dampers in this mixed-air plenum are
open (top), but the outdoor air damper
(left) is almost completely closed. Com-
plaints in the building indicate that
underventilation is a problem.
HVAC Systems and Indoor Air Quality 125
-------
temperature controller and thermostat
that are used to blend return air (typically
at 74ฐF) with outdoor air to reach a mixed
air temperature of 55ฐ to 65ฐF. (Mixed air
temperature settings above 65ฐF may lead
to the introduction of insufficient quanti-
ties of outdoor air for office space use.)
The mixed air is then further heated or
cooled for delivery to the occupied spaces.
Air economizer systems have a sensible
or enthalpy control that signals the outdoor
air damper to go to the minimum position
when it is too warm or humid outdoors.
Note that economizer cycles which do not
provide dehumidification may produce
discomfort even when the indoor tempera-
ture is the same as the thermostat setting.
If outdoor air make-up and exhaust are
balanced, and the zones served by each air
handler are separated and well defined, it is
possible to estimate the minimum flow of
outdoor air to each space and compare it to
ventilation standards such as ASHRAE 62-
1989. Techniques used for this evaluation
include the direct measurement of the
Proper air filtration can play an impor-
tant role in protecting the rest of the
HVAC system and in maintaining good
indoor air quality in occupied spaces.
Air filters should be selected and main-
tained to provide maximum filtration,
while not overtaxing the supply fan
capability or leading to "blow out" situa-
tions with no air filtration. Shown above
are, roll filter (top) and bag, panel and
pleated filters (below).
outdoor air at the intake and the calculation
of the percentage of outdoor air by a
temperature or CO2 balance. Carbon
dioxide measured in an occupied space is
also an indicator of ventilation adequacy.
Some investigators use tracer gases to
assess ventilation quantities and airflow
patterns. There are specific methods for
each of these assessments. See Appendix A
for more information.
Many HVAC designs protect the coils
by closing the outdoor air damper if the
airstream temperature falls below the
setpoint of a freezestat. Inadequate
ventilation can occur if a freezestat trips
and is not reset, or if the freezestat is set to
trip at an excessively high temperature.
Stratification of the cold outdoor air and
warmer return air in the mixing plenums is
a common situation, causing nuisance
tripping of the freezestat. Unfortunately,
the remedy often employed to prevent this
problem is to close the outdoor air damper.
Obviously, solving the problem in this way
can quickly lead to inadequate outdoor air
in occupied parts of the building.
Air Filters
Filters are primarily used to remove
particles from the air. The type and design
of a filter determine its efficiency at
removing particles of a given size and the
amount of energy needed to pull or push
air through the filter. Filters are rated by
different standards and test methods such
as dust spot and arrestance which measure
different aspects of performance. Seethe
discussion of ASHRAE Standard 52-76 on
page 138 of this appendix.
Low efficiency filters (ASHRAE Dust
Spot rating of 10% to 20% or less) are
often used to keep lint and dust from
clogging the heating and cooling coils of a
system. In order to maintain clean air in
occupied spaces, filters must also remove
bacteria, pollens, insects, soot, dust, and
dirt with an efficiency suited to the use of
the building. Medium efficiency filters
(ASHRAE Dust Spot rating of 30% to
126 Appendix B
-------
60%) can provide much better filtration
than low efficiency filters. To maintain the
proper airflow and minimize the amount of
additional energy required to move air
through these higher efficiency filters,
pleated-type extended surface filters are
recommended. In buildings that are
designed to be exceptionally clean, the
designers may specify the equipment to
utilize both a medium efficiency pre-filter
and a high efficiency extended surface
filter (ASHRAE Dust Spot rating of 85%
to 95%). Some manufacturers recommend
high efficiency extended surface filters
(ASHRAE Dust Spot rating of 85%)
without pre-filters as the most cost
effective approach to minimizing energy
consumption and maximizing air quality in
modern HVAC VAV systems that serve
office environments.
Air filters, whatever their design or
efficiency rating, require regular mainte-
nance (cleaning for some and replacement
for most). As a filter loads up with
particles, it becomes more efficient at
particle removal but increases the pressure
drop through the system, therefore
reducing airflow. Filter manufacturers can
provide information on the pressure drop
through their products under different
conditions. Low efficiency filters, if
loaded to excess, will become deformed
and even "blow out" of their filter rack.
When filters blow out, bypassing of
unfiltered air can lead to clogged coils and
dirty ducts. Filtration efficiency can be
seriously reduced if the filter cells are not
properly sealed to prevent air from
bypassing.
Filters should be selected for their
ability to protect both the HVAC system
components and general indoor air quality.
In many buildings, the best choice is a
medium efficiency, pleated filter because
these filters have a higher removal
efficiency than low efficiency filters, yet
they will last without clogging for longer
than high efficiency filters.
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Choice of an appropriate filter and
proper maintenance are important to
keeping the ductwork clean. If dirt
accumulates in ductwork and if the relative
humidity reaches the dewpoint (so that
condensation occurs), then the nutrients
and moisture may support the growth of
microbiologicals. Attention to air filters is
particularly important in HVAC systems
with acoustical duct liner, which is
frequently used in air handler fan housings
and supply ducts to reduce sound transmis-
sion and provide thermal insulation. Areas
of duct lining that have become contami-
nated with microbiological growth must be
replaced. (See later discussion of ducts
and duct cleaning.) Sound reduction can
also:be accomplished with the use of
special duct-mounted devices such as
attenuators or with active electronic noise
control.
Air handlers that are located in difficult-
to-access places .(e.g., in places which
require ladders for access, have inconve-
nient access doors to unbolt, or are located
on roofs with no roof hatch access) will be
Pleated medium efficiency
filters are often preferred
over low efficiency filters
because they offer added
protection to both the
HVAC equipment and to
indoor air quality, yet they
do not clog as easily as
high efficiency filters.
Medium efficiency filters do
need routine maintenance,
however, which the filter in
this photo did not receive.
HVAC Systems and Indoor Air Quality 127
-------
Without proper installation
and maintenance, rust and
corrosion may accumulate
In condensate pans under
heating and cooling coils.
The rust in this pan indi-
cates that it was installed
without a pitch or was
pitched in the wrong
direction, so that water
did not drain out properly.
more likely to suffer from poor air filter
maintenance and overall poor mainte-
nance. Quick release and hinged access
doors for maintenance are more desirable
than bolted access panels.
Filters are available to remove gases
and volatile organic contaminants from
ventilation air; however, these systems are
not generally used in normal occupancy
buildings. In specially designed HVAC
systems, permanganate oxidizers and
activated charcoal may be used for gaseous
removal filters. Some manufacturers offer
"partial bypass" carbon filters and carbon
impregnated filters to reduce volatile
organics in the ventilation air of office
environments. Gaseous filters must be
regularly maintained (replaced or regener-
ated) in order for the system to continue to
operate effectively.
Heating and Cooling Coils
Heating and cooling coils are placed in the
airstream to regulate the temperature of the
air delivered to the space. Malfunctions of
the coil controls can result in thermal
discomfort. Condensation on under-
insulated pipes and leakage hi piped
systems will often create moist conditions
conducive to the growth of molds, fungus,
and bacteria.
During the cooling mode (air condition-
ing), the cooling coil provides dehumidifi-
cation as water condenses from the air-
stream. Dehumidification can only take
place if the chilled fluid is maintained at a
cold enough temperature (generally below
45ฐF for water). Condensate collects in the
drain pan under the cooling coil and exits
via a deep seal trap. Standing water will
accumulate if the drain pan system has not
been designed to drain completely under
all operating conditions (sloped toward the
dram and properly trapped). Under these
conditions, molds and bacteria will
proliferate unless the pan is cleaned
frequently.
It is important to verify that condensate
lines have been properly trapped and are
charged with liquid. An improperly
trapped line can be a source of contamina-
tion, depending on where the line termi-
nates. A properly installed trap could also
be a source, if the water hi the trap
evaporates and allows air to flow through
the trap into the conditioned air.
During the heating mode, problems can
occur if the hot water temperature in the
heating coil has been set too low hi an
attempt to reduce energy consumption. If
enough outdoor ah- to provide sufficient
ventilation is brought in, that air may not
be heated sufficiently to maintain thermal
comfort or, in order to adequately condi-
tion the outdoor air, the amount of outdoor
air may be reduced so that there is insuffi-
cient outdoor air to meet ventilation needs.
128 Appendix B
-------
Humidification and
Dehumidlfication Equipment
In some buildings (or zones within
buildings), there are special needs that
warrant the strict control of humidity (e.g.,
operating rooms, computer rooms). This
control is most often accomplished by
adding humidification or dehumidificatioE
equipment and controls. In office facili-
ties, it is generally preferable to keep
relative humidities above 20% or 30%
during the heating season and below 60%
during the cooling season. ASHRAE
Standard 55-1981 provides guidance on
acceptable temperature and humidity
conditions. (See also the discussion of
humidity levels in Section 6.)
The use of a properly designed and
operated air conditioning system will
generally keep relative humidities below
60% RH during the cooling season, in
office facilities with normal densities and
loads. (See the previous discussion of the
cooling coil.)
Office buildings in cool climates that
have high interior heat gains, thermally
efficient envelopes (e.g., insulation), and
economizer cooling may require humidi-
fication to maintain relative humidity
within the comfort zone. When humidi-
fication is needed, it must be added in a
manner that prevents the growth of micro-
biologicals within the ductwork and air
handlers.
Steam humidifiers should utilize clean
steam, rather than treated boiler water, so
that occupants will not be exposed to
chemicals. Systems using media other
than clean steam must be rigorously
maintained hi accordance with the
manufacturer's recommended procedures
to reduce the likelihood of microbiological
growth.
Mold growth problems are more likely
if the humidistat setpoint located in the
occupied space is above 45%. The high
limit humidistat, typically located in the
ductwork downstream of the point at
Above: Occupants of this building
complained of an intermittent fish tank
odor. An Investigation showed that this
water spray humidification system is
regularly maintained. The coils are
washed roughly every two weeks using
fresh tap water, eliminating the need for
any use ofalgacides. Below: Further
investigation identified the fact that the
maintenance practice was causing the
odor problem. This picture of the
downstream side of the coils was taken
one day after the washing. A high
pressure stream of water caused algae *
in the water to foam and float for several
days, coinciding with the occupant
complaints.
HVAC Systems and Indoor Air Quality 129
-------
DUCT LEAKAGE
' Leakage of air from ducts can cause or exacerbate air quality prob-
lems, in addition to wasting energy. In general, sealed duct systems
specified with a leakage rate of less than 3% will have a superior life
; cycle cost analysis and reduce the likelihood of problems associated
with leaky ductwork. Examples of excessive duct leakage leading to
problems include:
"leakage of lightProffer-type diffusers at the diffuser/light fixture
; Interface when they are installed in a return plenum. Such leakage
has bef rt known to cause gross short-circuiting between supply and
return! wasting much of the conditioned air. If the "room" thermo-
stat Is located in the return plenum, the room can be very uncom-
fortable while the temperature in the plenum is operating at the
: control setpoirit.
ป leakage of supply ductwork due to loose-fitting joints and connec-
tions or "blow outs" of improperly fabricated seams
to leakage of return ducts located in crawl spaces or below slabs,
allowing soil gases and molds to enter the ductwork
which water vapor is added, is generally
set at 70% to avoid condensation (with a
potential for subsequent mold growth) in
the ductwork. Adding water vapor to a
building that was not designed for
humidifieatioa can have a negative impact
on the building structure and the
occupants' health, if condensation occurs
on cold surfaces or in wall or roof cavities.
Supply Fans
After passing through the coil section
where heat is either added or extracted, air
moves through the supply fan chamber and
the distribution system. Air distribution
systems commonly use ducts that are
constructed to be relatively airtight.
Elements of the building construction can
also serve as part of the air distribution
system (e.g., pressurized supply plenums
or return air plenums located in the cavity
space above the ceiling tiles and below the
deck of the floor above). Proper coordina-
tion of fan selection and duct layout during
the building design and construction phase
and ongoing maintenance of mechanical
components, filters, and controls are all
necessary for effective air delivery.
Fan performance is expressed as the
ability to move a given quantity of air
(cubic feet per minute or cfrn) at a given
resistance or static pressure (measured in
inches of water column). Airflow in
ductwork is determined by the size of the
duct opening, the resistance of the duct
configuration, and the velocity of the air
through the duct The static pressure in a
system is calculated using factors for duct
length, speed of air movement and changes
in the direction of air movement.
It is common to find some differences
between the original design and the final
installation, as ductwork must share
limited space with structural members and
other "hidden" elements of the building
system (e.g., electrical conduit, plumbing
pipes). Air distribution problems can
occur, particularly at the end of duct runs,
if departures from the original design
increase the friction hi the system to a
point that approaches the limit of fan
performance. Inappropriate use of long
runs of flexible ducts with sharp bends also
causes excessive friction. Poor system
balancing (adjustment) is another common
cause of air distribution problems.
Dampers are used as controls to
restrict airflow. Damper positions may be
relatively fixed (e.g., set manually during
system testing and balancing) or may
change in response to signals from the
control system. Fire and smoke dampers
can be triggered to respond to indicators
such as high temperatures or signals from
smoke detectors. If a damper is designed
to modulate, it should be checked during
inspections to see that it is at the proper
setting. ASHRAE and the Associated Air
Balance Council both provide guidance on
proper intervals for testing and balancing.
Ducts
The same HVAC system that distributes
conditioned air throughout a building can
distribute dust and other pollutants,
including biological contaminants. Dirt or
13O Appendix B
-------
dust accumulation on any components of
an air handling system its cooling coils,
plenums, ducts, and equipment housing
may lead to contamination of the air
supply.
There is widespread agreement that
building owners and managers should take
great precautions to prevent dirt, high
humidity, or moisture from entering the
ductwork; there is less agreement at
present about when measures to clean up
are appropriate or how effective cleaning
techniques are at making long-term
improvements to the air supply or at
reducing occupant complaints.
The presence of dust in ductwork does
not necessarily indicate a current microbio-
logical problem. A small amount of dust
on duct surfaces is normal and to be
expected. Special attention should be
given to trying to find out if ducts are
contaminated only where specific prob-
lems are present, such as: water damage or
biological growth observed in ducts, debris
in ducts that restricts airflow, or dust
"discharging from supply diffusers.
Problems with dust and other contami-
nation in the ductwork are a function of
filtration efficiency, regular HVAC system
maintenance, the rate of airflow, and good
housekeeping practices in the occupied
space. Problems with biological pollutants
can be prevented by minimizing dust and
dirt build-up, promptly repairing leaks and
water damage, preventing moisture
accumulation in the components that are
supposed to be dry, and cleaning the
components such as the drip pans that
collect and drain water.
In cases where sheet metal ductwork
has become damaged or water-soaked,
building owners will need to undertake
clean-up or repair procedures. For
example, in cases where the thermal liner
or fiberboard has become water-soaked,
building managers will need to replace the
affected areas. These procedures should
be scheduled and performed in a way that
does not expose building occupants to
increased levels of pollutants and should
be carried out by experienced workers.
Correcting problems that allowed the
ductwork to become contaminated in the
first place is important. Otherwise, the
corrective action will only be temporary.
The porous surface of fibrous glass duct
liner presents more surface area (which
can trap dirt and subsequently collect
water) than sheet metal ductwork. It is
therefore particularly important to pay
attention to the proper design, installation,
filtration, humidity, and maintenance of
ducts that contain porous materials. In
addition, techniques developed for
cleaning unlined metal ducts often are not
suitable for use with fibrous glass thermal
liner or fiberboard. Such ducts may
require a special type of cleaning to
maintain the integrity of the duct (i.e., no
heavy brushing tools that might fray the
inner lining) while removing dirt and
debris.
More research on both the efficacy and
the potential for unintended exposures to
building occupants from various cleaning
techniques is needed before firm guidance
can be provided regarding duct cleaning.
Pay attention to worker safely when
working with air handling systems
including during duct cleaning. Any
worker who may potentially breathe duct
contaminants or biocides should wear
suitable protective breathing apparatus.
Workers who are doing the duct cleaning
should be encouraged to also look for
other types of problems, such as holes or
gaps in the ducts that could allow contami-
nants to enter the ventilation airstream.
Building managers can obtain more
information on the issue of HVAC
contamination and cleaning from the
professional standards developed by some
trade associations (See Guidelines of Care
Developed by Professional and Trade
Associations in Section 5 and refer to
Appendix G for a list of organizations
with expertise and materials on these
issues.)
HVAC Systems and Indoor Air Quality 131
-------
PRELIMINARY RECOMMENDATIONS ON DUCT CLEANING
1, Any duct cleaning should be
scheduled during periods when
the building Is unoccupied to
prevent exposure to chemicals and
loosened particles.
The air handling unit should not be
used during the cleaning or as an
air movement device for the
cleaning process. The National Air
Duct Cleaning Association recom-
mends that the system should be
run to allow at least eight air
changes in the occupied space
when duct cleaning has been
completed.
2. Negative air pressure that will
draw pollutants to a vacuum
collection system should be
maintained at all times in the duct
cleaning area to prevent migration
of dust, dirt, and contaminants
Info occupied areas.
Where possible, use vacuum
equipment or fans during cleaning
and sanitizing to make sure that
cleaning vapors are exhausted to
tha outside and do not enter the
occupied space.
3. If it is determined that the
ductwork should be cleaned,
caraful attention must be given to
protecting the ductwork.
When gaining access to sheet
metal ducts for cleaning purposes,
ft Is essential to seal the access
hole properly In order to maintain
the Integrity of the HVAC system.
Access doors are recommended if
the system is to be cleaned
periodically, and all access holes
should be identified on the
building's mechanical plans.
Particular attention is warranted
when cutting fibrous glass ducts,
and manufacturers' recommended
procedures for sealing should be
followed stringently. Use existing
duct system openings where
possible because It is difficult to
repair the damage caused by
cutting new access entries into the
ductwork. Large, high volume
vacuum equipment should only be
used with extreme care because high
negative pressure together with
limited airflow can collapse ducts.
4. Duct cleaning performed with high
velocity airflow (i.e., greater than
6,000 cfm) should include gentle,
well-controlled brushing of duct
surfaces or other methods to
dislodge dust and other particles.
Duct cleaning that relies only on a
high velocity airflow through the
ducts Is not likely to achieve satisfac-
tory results because the flow rate at
the duct surface remains too low to
remove many particles.
5. OnlyHEPA filtered {high-efficiency
particle arrestor} vacuuming equip-
ment should be used if the vacuum
collection unit is inside the occupied
space.
Conventional vacuuming equipment
may discharge extremely fine
paniculate matter back into the
atmosphere, rather than collecting it.
Duct cleaning equipment that draws
the dust and dirt into a collection unit
outside the building is also available.
People should not be allowed to
remain in the immediate vicinity of
these collection units.
6. Ifbiocides are to be used, then
select only products registered by
EPA for such use, use the products
according to the manufacturer's
directions, and pay careful attention
to the method of application.
At present, EPA accepts claims and
therefore registers antimicrobials for
use only as sanitizers, not disinfec-
tants or sterilizers in HVAC systems.
(See Appendix F for definitions of
antimicrobials.) There is some
question about whether there are
any application techniques that
will deposit a sufficient amount of
the blocrde to kill bacteria, germs,
or other biologicals that may be
present. Materials such as deodoriz-
ers that temporarily eliminate odors
caused by microorganisms provide
only a fresh smell, and are not
intended to provide real control of
microbiological contaminants.
7. Use of sealants to cover interior
ductwork surfaces is not recom-
mended.
No application techniques have
been demonstrated to provide a
complete or long-term barrier to
microbiological growth, nor have
such materials been evaluated for
their potential health effects on
occupants. In addition, using
sealants alters the surface burning
characteristics of the duct material
and may void the fire safety rating
of the ductwork.
8. Careful cleaning and sanitizing of
any parts of coils and drip pans can
reduce microbiological pollutants.
Prior to using sanitizers, deodoriz-
ers, or any cleansing agents,
carefully read the directions on the
product label. Once cleaned, these
components should be thoroughly
rinsed and dried to prevent expo-
sure of building occupants to the
cleaning chemicals.
9. Water-damaged or contaminated
porous materials in the ductwork
or other air handling system
components should be removed
and replaced.
Even when such materials are
thoroughly dried, there is no way to
guarantee that all microbial growth
has been eliminated.
10. After the duct system has been
cleaned and restored to use, a
preventive maintenance program
will prevent the recurrence of
problems.
Such a program should Include
particular attention to the use and
maintenance of adequate filters,
control of moisture in the HVAC
system, and periodic inspection and
cleaning of HVAC system compo-
nents. (See discussion of Preven-
tive Maintenance on page 36 in
Section 5.)
132 Appendix B
-------
Terminal Devices
Thermal comfort and effective contami-
nant removal demand that air delivered
into a conditioned space be properly
distributed within that space. Terminal
devices are the supply diffusers, return and
exhaust grilles, and associated dampers
and controls that are designed to distribute
air within a space and collect it from
space. The number, design, and location
(ceiling, wall, floor) of terminal devices
are very important. They can cause a
HVAC system with adequate capacity to
produce unsatisfactory results, such as
drafts, odor transport, stagnant areas, or
short-circuiting.
Occupants who are uncomfortable
because of disMbution deficiencies (drafts,
odor transport, stagnant air, or, uneven
temperatures) often try to compensate fay
adjusting or blocking the flow of air from
supply outlets. Adjusting system flows
without any knowledge of the proper
frequently disrupts the proper
supply of air to adjacent areas. Distribu-
tion problems can also be produced if the
arrangement of movable partitions,
shelving, or other furnishings interferes
with airflow. Such problems often occur if
walls are moved or added without evaluat-
ing the expected impact on airflows,
Return Air Systems
In many modern buildings the above-
ceiling space is utilized for the unducted
passage of ream air. This type of system
approach often reduces initial HVAC
system costs, but requires that the designer,
maintenance personnel, and contractors
obey strict guidelines related to health and.
safety codes (e.g., building codes) that
must be followed for materials and devices
that are located in the plenum. In addition,
if a ceiling plenum is used for the collee-
tion of return air, openings into the ceiling
plenum created by the removal of ceiling
tiles will disrupt airflow patterns. It is
particularly important to maintain (he
integrity of the ceiling and adjacent walls
in areas that are designed to be exhausted,
as supply closets, bathrooms, and
chemical storage areas.
After return air enters either a ducted
return air grille or a ceiling plenum, it is
returned to the air handlers. Some systems
utilize return fans in addition to supply
fans in order to properly the
distribution of air. When a supply and
return fan are utilized, especially in a VAV
system, their operation must be coordi-
nated in order to prevent under- or over-
pressurization of the occupied space or
overpressurization of the mixing plenum in
the air handler.
Exhausts, Exhaust Fans, and
Pressure Belief
Most buildings are required by law (e.g.,
building or plumbing codes) to provide for
exhaust of areas where contaminant
sources are strong, such as toilet facilities,
janitorial closets, cooking facilities, and
Other areas where
exhaust is frequently recommended but
Return air is frequently car-
ried through non-ducted
plenums. It is more difficult
to control leakage of pollut-
ants into or out of this type
of return air system than a
ducted system.
HVAC Systems and Indoor Air Quality 133
-------
may not be legally required include:
reprographics areas, graphic arts facilities,
beauty salons, smoking lounges, shops,
and any area where contaminants are
known to originate.
For successful confinement and exhaust
of identifiable sources, the exhausted area
must be maintained at a lower overall
pressure than surrounding areas. Any area
that is designed to be exhausted must also
be isolated (disconnected) from the return
air system so that contaminants are not
transported to another area of the building.
In order to exhaust air from the build-
ing, make-up air from outdoors must be
brought into the HVAC system to keep the
building from being run under negative
pressure. This make-up air is typically
drawn in at the mixed air plenum as
described earlier and distributed within the
building. For exhaust systems to function
properly, the make-up air must have a clear
path to the area that is being exhausted.
It is useful to compare the total cfm of
powered exhaust to the minimum quantity
of mechanically-introduced outdoor air.
To prevent operating the building under
negative pressures (and limit the amount of
unconditioned air brought into the building
by infiltration), the amount of make-up air
drawn in at the air handler should always
be slightly greater than the total amount of
relief air, exhaust air, and air exfiltrating
through the building shell. Excess make-
up air is generally relieved at an exhaust or
relief outlet in the HVAC system, espe-
cially in air economizer systems. In
addition to reducing the effects of un-
wanted infiltration, designing and operat-
ing a building at slightly positive or neutral
pressures will reduce the rate of entry of
soil gases when the systems are operating.
For a building to actually operate at a
slight positive pressure, it must be tightly
constructed (e.g., specified at less than
one-half air change per hour at 0.25
pascals). Otherwise unwanted exfiltration
will prevent the building from ever
achieving a neutral or slightly positive
pressure.
Self-Contained Units
In some designs, small decentralized units
are used to provide cooling or heating to
interior or perimeter zones. With the
exception of induction units, units of this
type seldom supply outdoor air. They are
typically considered a low priority mainte-
nance item. If self-contained units are
overlooked during maintenance, it is not
unusual for them to become a significant
source of contaminants, especially for the
occupants located nearby.
Controls
HVAC systems can be controlled manually
or automatically. Most systems are con-
trolled by some combination of manual and
automatic controls. The control system can
be used to switch fans on and off, regulate
the temperature of air within the conditioned
space, or modulate airflow and pressures by
controlling fan speed and damper settings.
Most large buildings use automatic controls,
and many have very complex and sophisti-
cated systems. Regular maintenance and
calibration are required to keep controls in
good operating order. All programmable
timers and switches should have "battery
backup" to reset the controls in the event of a
power failure.
Local controls such as room thermostats
must be properly located in order to
maintain thermal comfort. Problems can
result from:
thermostats located outside of the
occupied space (e.g., in return plenum)
poorly designed temperature control
zones (e.g., single zones that combine
areas with very different heating or
cooling loads)
thermostat locations subject to drafts or
to radiant heat gain or loss (e.g., exposed
to direct sunlight)
134 Appendix B
-------
thermostat locations affected by heat
from nearby equipment
To test whether or not a thermostat is
functioning properly, try setting it to an
extreme temperature. This experiment will
show whether or not the system is respond-
ing to the signal in the thermostat, and
also provides information about how the
HVAC system may perform under extreme
conditions.
Boilers
Like any other part of the HVAC system, a
boiler must be adequately maintained to
operate properly. However, it is particu-
larly important that combustion equipment
operate properly to avoid hazardous
conditions such as explosions or carbon
monoxide leaks, as well as to provide good
energy efficiency. Codes in most parts of
the country require boiler operators to be
properly trained and licensed.
Both ASME and ASHRAE have made
recommendations of how much combus-
tion air is needed for fuel burning appli-
ances.
Elements of boiler operation that are
particularly important to indoor air quality
and thermal comfort include:
Operation of the boiler and distribution
loops at a high enough temperature to
supply adequate heat in cold weather.
Maintenance of gaskets and breeching to
prevent carbon monoxide from escaping
into the building.
Maintenance of fuel lines to prevent any
leaks that could emit odors into the
building.
Provision of adequate outdoor air for
combustion.
Design of the boiler combustion exhaust
to prevent re-entrainment (especially
from short boiler stacks or into multi-
story buildings that were added after the
boiler plant was installed).
Modern office buildings tend to have
much smaller capacity boilers than older
buildings because of advances in energy
efficiency. In some buildings, the primary
heat source is waste heat recovered from
the chiller (which operates year-round to
cool the core of the building).
Cooling Towers
Maintenance of a cooling tower ensures
proper operation and keeps the cooling
tower from becoming^ niche for breeding
pathogenic bacteria, such as Legionella
organisms. Cooling tower water quality
must be properly monitored and chemical
treatments used as necessary to minimize
conditions that could support the growth of
significant amounts of pathogens. Proper
maintenance may also entail physical
cleaning (by individuals using proper
protection) to prevent sediment accumula-
tion and installing drift eliminators.
It is important to determine
periodically whether the
HVAC controls are correctly
calibrated. In addition, time
clocks must be checked to
see if they are properly set
and running. Power
failures frequently cause.
time clocks to be out of
adjustment.
HVAC Systems and Indoor Air Quality 135
-------
FIGURE B-2: Selected Ventilation Recommendations
Application
Occupancy
(people/1000 ft2)
Cfm/person
Cfm/ff?
~ Food and Beverage
San/ice
5-
Offices
Dining rooms
Cafeteria, fast food
" : Bars, cocktail lounges
Kitchen (cooking)
Office space
Reception areas
Conference rooms
70
100
100
20
7
60
50
20
20
30
15
20
15
20
Public Spaces
Smoking lounge
* Elevators
70
SOURCE: ASHRAE Standard 62-1989, Ventilation for Acceptable Air Quality
60
1.00
Retail Stores, Sales
Floors, Showroom
Floors
Sports and
Amusement
Theaters
Education
Hotels, Motels,
Resorts,
Dormitories
Basement and street
Upper floors
Malls and arcades
7 Smoking lounge
Spectator areas
Game rooms
Playing floors
Ballrooms and discos
Lobbies
- Auditorium
Classroom
Music rooms
Libraries
Auditoriums
Bedrooms
Living rooms
.Lobbies
Conference rooms
Assembly rooms
30
20
20
70
150
70
30
100
150
150
50
50
20
150
30
50
120
0,30
0.20
0.20
60
15
25
20
, 25
20
, , 15 ; . . , "
' '15
15
15
15
SOcfm/room
30cfm/room
15
20
15
136 Appendix B
-------
Water Chillers
Water chillers are frequently found in large
building air conditioning systems because
of the superior performance they offer, A
water chiller must be maintained in proper
working condition to perform its function
of removing the heat from the building,
Chilled water supply temperatures should
operate in the range of 45ฐF or colder in
order to provide proper moisture removal
during humid weather. Piping should be
insulated to prevent condensation.
Other than thermal comfort, IAQ
concerns associated with water chillers
involve potential release of the working
fluids from the chiller system. The rupture
disk (safety release) of the system should
be piped to the outdoors, and refrigerant
leaks should be located and repaired.
Waste oils and spent refrigerant should be
disposed of properly.
ASHRAE STANDARDS AND
GUIDELINES
Standard 62-1989, "Ventilation
for Acceptable Air Quality"
*
ASHRAE 62-1989 is intended to assist
professionals in the proper design of
ventilation systems for buildings. Hie
standard presents two procedures for
ventilation design: a "Ventilation Rate"
procedure and an "Air Quality" procedure.
With the Ventilation Rate procedure,
acceptable air quality is achieved by
specifying a given quantity and quality of
outdoor air based upon occupant density
and space usage. Examples of the tables
listing the prescriptive amounts of outdoor
air for the Ventilation Rate procedure are
presented at the end of this section.
The Air Quality procedure is a perfor-
mance specification that allows acceptable
air quality to be achieved within a space by
controlling for known and specifiable
contaminants. This procedure is seldom
used because source strength is usually not
known,
Whichever procedure is utilized in the
design, the standard states that the design
criteria and assumptions shall be docu-
mented and made available to those
responsible for the operation and mainte-
nance of the system.
Important features of ASHRAE 62-
1989 include:
a definition of acceptable air quality
ซ a discussion of ventilation effectiveness
* the recommendation of the use of source
control through isolation and local
exhaust of contaminants
recommendations for the use of heat
recovery ventilation
a guideline for allowable carbon dioxide
levels
appendices listing suggested possible
guidelines for common indoor pollutants
Standard 55-1981, "Thermal
Environmental Conditions for
Human Occupancy"
ASHRAE 55-1981 covers several environ-
mental parameters including: temperature,
radiation, humidity, and air movement
The standard specifies thermal environ-
mental conditions for the comfort of
healthy people in normal indoor environ-
ments for winter and summer conditions.
It also attempts to introduce limits on the
temperature variations within a space. In
addition to specifications for temperature
and humidity, guidelines are given for air
movement, temperature cycling, tempera-
ture drift, vertical temperature difference,
radiant asymmetry, and floor temperatures.
Adjustment factors are described for
various activity levels of the occupants,
and different clothing levels.
Important features of this standard
include:
a definition of acceptable thermal
comfort
HVAC Systems and Indoor Air Quality 137
-------
This air washer is used to
nmove particles and
wstar-solubls gaseous
contaminants and may also
control temperature and
humidity in the airstream.
Such systems are subject
to severs bacterial
contamination.
a discussion of the additional
environmental parameters that must
be considered
ป recommendations for summer and winter
comfort zones for both temperature and
relative humidity
a guideline for making adjustment for
activity levels
guidelines for making measurements
It should be noted that space tempera-
tures above 76ฐP but within the summer
comfort envelope have nevertheless been
associated with IAQ complaints in offices,
Note: As of summer 1991, a revised
Standard 55 was nearly ready.
Standard 62-76, "Method of
Testing Air-Cleaning Devices
Used In General Ventilation for
Removing Participate Matter"
This standard is intended to assist profes-
sionals in the evaluation of air cleaning
systems for particle removal. Two test
methods are described: the weight
arrestance test and the atmospheric dust
spot test. The standard discusses differ-
ences in results from the weight arrestance
test and the atmospheric dust spot test.
The atmospheric dust spot test is the test
used to determine the "efficiency " of an
air cleaner. The values obtained with
these two tests are not comparable. For
example, a filter with a weight arrestance
of 90% may have an efficiency by the
atmospheric dust spot test below 40%.
The weight arrestance test is generally
used to evaluate low efficiency filters
designed to remove the largest and
heaviest particles; these filters are com-
monly used in residential furnaces and/or
air-conditioning systems or as upstream
filters for other air cleaning devices. For
the test, a standard synthetic dust is fed
into the air cleaner and the proportion (by
weight) of the dust trapped on the filter is
determined. Because the particles in the
standard dust are relatively large, the
weight arrestance test is of limited value in
assessing the removal of smaller, respi-
rable-size particles from indoor air.
The atmospheric dust spot test is
usually used to rate medium efficiency Mr
cleaners. The removal rate is based on the
cleaner's ability to reduce soiling of a
clean paper target, an ability dependent on
the cleaner removing very fine particles
from the air. However, it should be noted
that this test addresses the overall effi-
ciency of removal of a complex mixture of
dust, and that removal efficiencies for
different size particles may vary widely.
Recent studies by EPA, comparing
ASHRAB ratings to filter efficiencies for
particles by size, have shown that efficien-
cies for particles in the size range of 0.1 to
1 microgram are much lower than the
ASHRAB rating.
Important features of this ASHRAE
standard include:
definitions of arrestance and efficiency
establishment of a uniform comparative
testing procedure for evaluating the
performance of air cleaning devices used
in ventilation systems
138 Appendix B
-------
establishment of a uniform reporting
method/or performance
methods for evaluating resistance to
airflow and dust-holding capacity
No comparable guidelines or standards
are currently available for use in assessing
the ability of air cleaners to remove gas-
eous pollutants or radon and its progeny.
Guideline 1-1989 "Guideline for
the Commissioning of HVAC
Systems"
This guideline is intended to assist profes-
sionals by providing procedures and meth-
ods for documenting .and verifying the
performance of HVAC systems so that
they operate in conformity with the design
intent. The guideline presents a format for
documenting the occupancy requirements,
design assumptions, and the design intent
for the HVAC system. It provides a for-
mat for testing the system for acceptance
by the owner. In addition, the guideline
addresses adjustments of the system to
meet actual occupancy needs within the
capacity of the system when changes in
building use are made and
recommissioning is warranted.
Important features of this guideline
include:
definition of the commissioning process
discussion of the process involved in a
proper commissioning procedure
sample specification and forms for log-
ging information
recommendation for the implementation
of corrective measures as warranted
guidelines for operator training
guidelines for periodic maintenance and
recommissioning as needed
HVAC Systems and Indoor Air Quality 139
-------
Page Intentionally Blank
-------
Appendix C:
Moisture, Mold and MiSdew
M
I olds and mildew are fungi that grow
on the surfaces of objects, within pores,
and in deteriorated materials. They can
cause discoloration and odor problems,
deteriorate building materials, and lead to
allergic reactions in susceptible individu-
als, as well as other health problems.
The following conditions are necessary
for mold growth to occur on surfaces:
temperature range above 40ฐF and below
100ฐF
mold spores
nutrient base (most surfaces contain
nutrients)
moisture
Human comfort constraints limit the use
of temperature control. Spores are almost
always present in outdoor and indoor air,
and almost all commonly used construc-
tion materials and furnishings can provide
nutrients to support mold growth. Dirt on
surfaces provides additional nutrients.
Cleaning and disinfecting with non-
polluting cleaners and antimicrobial agents
provides protection against mold growth.
Other sections of this document have
discussed the importance of building
maintenance and proper sanitation hi
preventing IAQ problems. However, it is
virtually impossible to eliminate all
nutrients. Moisture control is thus an
important strategy for reducing mold
growth.
Mold growth does not require the
presence of standing water; it can occur
when high relative humidity or the
hygroscopic properties (the tendency to
absorb and retain moisture) of building
surfaces allow sufficient moisture to
accumulate. Relative humidity and the
factors that govern it are often misunder-
stood. This appendix is intended to give
building managers an understanding of the
factors that govern relative humidity, and
to describe common moisture problems
and their solutions.
BACKGROUND ON RELATIVE
HUMIDITY, VAPOR PRESSURE,
AND CONDENSATION
Water enters buildings both as a liquid and
as a gas (water vapor). Water, in its liquid
form, is introduced intentionally in
bathrooms, kitchens, and laundries and
accidentally by way of leaks and spills.
Some of that water evaporates and joins
the water vapor that is exhaled by building
occupants as they breathe or that is
introduced by humidifiers. Water vapor
also moves in and out of the building as
part of the air that is mechanically intro-
duced or that infiltrates and exfiltrates
through openings in the building shell. A
There were complaints of
visible water damage and
musty odors in this senior
citizen housing complex.
Investigators confirmed that
the problem was rain entry
by using an array of hoses
to spray the walls with
water, while operating the
building under negative
pressure. The test showed
that rain was entering at the
joints of the exterior
cladding, rather than at
cracks around windows.
Moisture, Mold and Mildew 141
-------
FIGURE C-1: Moisture Gain in a Building
Air leakage
(carrying moisture)
by door openings and
thru cracks and crevices
Internal moisture release
by people, showers,
wet clothes and towels
Diffusion through
doors, walls, partitions
Liquid water
thru cracks
and then evaporated
Leakage around
electric plugs and
cracks in wall
Moisture Gain = Leakage + Diffusion + Internal
Courtesy of Dean Wallace
Shakun, Clayton State
College, Morrow, GA
lesser amount of water vapor diffuses into
and out of the building through the
building materials themselves. Figure C-1
illustrates locations of moisture entry.
The ability of air to hold water vapor
decreases as the air temperature is lowered.
If a unit of air contains half of the water
vapor it can hold, it is said to be at 50%
relative humidity (RH). As the ak cools,
the relative humidity increases. If the air
contains all of the water vapor it can hold,
it is at 100% RH, and fee water vapor
condenses, changing from a gas to a liquid.
It is possible to reach 100% RH without
changing the amount of water vapor in the
air (its "vapor pressure" or "absolute
humidity"); all that is required is for the air
temperature to drop to the "dew point."
Relative humidity and temperature
often vary within a room, while the
absolute humidity in the room air can
usually be assumed to be uniform. There-
fore, if one side of the room is warm and
the other side cool, the cool side of the
room has a higher RH than the warm side.
The highest RH in a room is always
next to the coldest surface. This is referred
as the "first condensing surface," as it will
142 Appendix C
-------
FIGURE C-2: Relationship of Temperature, Relative Humidity, and Moisture in the Air
A relative humidity reading taken in a room will only give an
accurate indication of the actual amount of moisture present if a
temperature reading is taken at the same time. The chart below
shows that air at 70ฐ F and 40% RH contains approximately
0.006 pounds of moisture per pound of dry air (as indicated by
the bold line), while air that is at 50ฐ F and 40% RH contains
approximately 0.003 pounds of moisture per pound of dry air
(as indicated by the dashed line). Although both are at 40% RH,
the 70ฐ f air contains roughly twice as much moisture as the
50ฐFair.
Relative
Humidity
(%RH)
.000
40ฐF
50ฐF
60ฐF
Temperature 30ฐF
(ฐFarenheitJ
11 70ฐF at 40% relative humidity
ซ 50ฐF at 40% relative humidity
70ฐF
80ฐF
90ฐF
100ฐF 110ฐF
120ฐF
SOURCE: Adapted from Psychometric Chart from ASHfiAE Fundamentals, 1981
be the location where condensation first
occurs, if the relative humidity at the
surface reaches 100%. It is important to
understand this when trying to understand
why mold is growing on one patch of waE
or only along the wall-ceiling joint It is
likely that the surface of the wall is cooler
than the room air because there is a yoid in
the insulation or because wind is blowing
through cracks in the exterior of the
building.
TAKING STEPS TO REDUCE
MOISTURE
Mold and rnMew growth can be reduced
where relative humidities near surfaces can
be maintained below the dew point. This
can be accomplished by reducing the
moisture content (vapor pressure) of the >
air, increasing air movement at the surface,
or increasing the air temperature (either the
general space temperature or the tempera-
ture at building surfaces).
Moisture, Mold and Mildew 143
-------
Above: In this building, mold and
mildew spots appeared on drywall
joints on the interior walls. When the
wall was cut open, mold growth was
visible in the wall cavity and the
structural steel showed corrosion. The
problem was caused by construction
moisture trapped between the interior
finish and the exterior sheathing. The
solution was to modify the exterior wall
so that moisture could vent to the
outdoors. Below: This is visual
evidence of air movement through the
building shell. The water vapor in the
warm, humid indoor air has condensed
and frozen on the exterior wall.
Either surface temperature or vapor
pressure can be the dominant factor in
causing a mold problem. A surface
temperature-related mold problem may not
respond very well to increasing ventilation,
whereas a vapor pressure-related mold
problem may not respond well to increas-
ing temperatures. Understanding which
factor dominates will help in selecting an
effective control strategy.
Consider an old, leaky, poorly insulated
building. It is in a heating climate and
shows evidence^of mold and mildew.
Since the building is leaky, its high natural
air exchange rate dilutes interior airborne
moisture levels, maintaining a low absolute
humidity during the heating season.
Providing mechanical ventilation in this
building in an attempt to control interior
mold and mildew probably will not be
effective in this case. Increasing surface
temperatures by insulating the exterior
walls, and thereby reducing relative
humidities next to the wall surfaces, would
be a better strategy to control mold and
mildew.
Reduction of surface temperature-
dominated mold and mildew is best
accomplished by increasing the surface
temperature through either or both of the
following approaches:
Increase the temperature of the air near
room surfaces either by raising the
thermostat setting or by improving air
circulation so that supply air is more
effective at heating the room surface.
Decrease the heat loss from room
surfaces either by adding insulation or by
closing cracks in the exterior wall to
prevent wind-washing (air that enters a
wall at one exterior location and exits
another exterior location without
penetrating into the building).
Vapor pressure-dominated mold and
mildew can be reduced by one or more of
the following strategies:
144 Appendix C
-------
source control (e.g., direct venting of
moisture-generating activities such as
showers) to the exterior
dilution of moisture-laden indoor air
with outdoor air that is at a lower
absolute humidity
dehumidification
Note that dilution is only useful as a
control strategy during heating periods,
when cold outdoor air tends to contain less
moisture. During cooling periods, outdoor
air often contains as much moisture as
indoor air.
IDENTIFYING AND CORRECTING
COMMON PROBLEMS FROM
MOLD AND MILDEW
Exterior Corners
Exterior corners are common locations for
mold and mildew growth in heating
climates, and in poorly insulated buildings
in cooling climates. They tend to be closer
to the outdoor temperature than other parts
of the building surface for one or more of
the following reasons:
poor air circulation (interior)
wind-washing (exterior)
low insulation levels
greater surface area of heat loss
Sometimes mold and mildew growth
can be reduced by removing obstructions
to airflow (e.g., rearranging furniture).
Buildings with forced air heating systems
and/or room ceiling fans tend to have
fewer mold and mildew problems than
buildings with less air movement, other
factors being equal.
"Set Back" Thermostats
Set back thermostats are commonly used to
reduce energy consumption during the
heating season. Mold and mildew growth
can occur when building temperatures are
lowered during unoccupied periods.
(Maintaining a room at too low a tempera-
ture can have the same effect as a set back
thermostat.) Mold and mildew can often
HOW TO IDENTIFY THE CAUSE OF A MOLD AND
MILDEW PROBLEM ..'. ; ":.;...,.". .-..'.
Mold and mildew are commonly found on the exterior wall surfaces of
corner rooms in heating climate locations* An exposed corner room is
likely to be significantly colder than adjoining rooms, so that it has a
higher relative humidity |RH) than other rooms at the same water
Vapor pressure. If mold and mildew growth are found in a corner
roprn, then relative huniidities next to the room surfaces are above
^70%. However, is the RH above 70% at the surfaces because the room
; is too cold or because there fs too much moisture present (high water
vapor pressure)?
:: v The amount of moisture in the room can be estimated by measur-
ing Both temperature and RH at the same location and at the same
time. Suppose there are two cases. In the first case, assume that the
RH is 30% and the temperature is 70ฐF in the middle of the room, the
l
-------
maintenance interior finishes (e.g.,
impermeable wall coverings such as vinyl
wallpaper) which can trap moisture
between the interior finish and the gypsum
board. Mold growth can be rampant when
these interior finishes are coupled with
cold spots and exterior moisture.
Possible solutions for this problem
include:
preventing hot, humid exterior air from
contacting the cold interior finish (i.e.,
controlling the vapor pressure at the
surface)
eliminating the cold spots (i.e., elevating
the temperature of the surface) by
relocating ducts and diffusers
ensuring that vapor barriers, facing
sealants, and insulation are properly
specified, installed, and maintained
increasing the room temperature to avoid
overcooling
In this case, increasing temperature
decreases energy consumption, though it
could cause comfort problems.
Thermal Bridges
Localized cooling of surfaces commonly
occurs as a result of "thermal bridges,"
elements of the building structure that are
highly conductive of heat (e.g., steel studs
in exterior frame walls, uninsulated
window lintels, and the edges of concrete
floor slabs). Dust particles sometimes
mark the locations of thermal bridges,
because dust tends to adhere to cold spots.
The use of insulating sheathings
significantly reduces the impact of thermal
bridges in building envelopes.
Windows
In winter, windows are typically the
coldest surfaces hi a room. The ulterior
surface of a window is often the first
condensing surface in a room.
Condensation on window surfaces has
historically been controlled by using storm
windows or "insulated glass" (e.g., double-
glazed windows or selective surface gas-
filled windows) to raise interior surface
temperatures. The advent of higher
performance glazing systems has led to a
greater incidence of moisture problems in
heating climate building enclosures,
because the buildings can now be operated
at higher interior vapor pressures (moisture
levels) without visible surface condensa-
tion on windows. In older building
enclosures with less advanced glazing
systems, visible condensation on the
windows often alerted occupants to the
need for ventilation to flush out interior
moisture (so they opened the windows).
Concealed Condensation
The use of thermal insulation in wall
cavities increases ulterior surface tempera-
tures hi heating climates, reducing the
likelihood of ulterior surface mold, mildew
and condensation. However, the use of
thermal insulation also reduces the heat
loss from the conditioned space into the
wall cavities, decreasing the temperature in
the wall cavities and therefore increasing
the likelihood of concealed condensation.
The first condensing surface in a wall
cavity in a heating climate is typically the
inner surface of the exterior sheathing, the
"back side" of plywood or fiberboard. As
the insulation value is increased in the wall
cavities, so does the potential for hidden
condensation.
Concealed condensation can be con-
trolled by either or both of the following
strategies:
Reducing the entry of moisture into the
wall cavities (e.g., by controlling
infiltration and/or exfiltration of mois-
ture-laden air); and/or
Elevating the temperature of the first
condensing surface. In heating climate
locations, this change can be made by
installing exterior insulation (assuming
that no significant wind-washing is
occurring). In cooling climate locations,
this change an be made by installing
insulating sheathing to the interior of the
wall framing and between the wall
framing and the interior gypsum board.
146 Appendix C
-------
Appendix D: Asbestos
11 A
JPmsbestos" describes six naturally
occurring fibrous minerals found in certain
types of rock formations. When mined
and processed, asbestos is typically sepa-
rated into very thin fibers that are normally
invisible to the naked eye. They may
remain in the air for many hours if re-
leased from asbestos-containing material
(ACM) and may be inhaled during this
time. Three specific diseases asbestosis
(a fibrous scarring of the lungs), lung
cancer, and mesothelioma (a cancer of the
lining of the chest or abdominal cavity)
have been linked to asbestos exposure. It
may be 20 years or more after exposure
before symptoms of these diseases appear;
however, high levels of exposure can re-
sult in respiratory diseases within a shorter
period of time.
Most of the health problems resulting
from asbestos exposure have been experi-
enced by workers whose jobs exposed
them to asbestos in the air over a pro-
longed period without the worker protec-
tion that is now required. Asbestos fibers
can be found nearly everywhere in our
environment, usually at very low levels.
While the risk to occupants is likely to be
small, health concerns remain, particularly
for the custodial and maintenance workers
in a building. Their jobs are likely to bring
them into proximity to ACM and may
sometimes require them to disturb the
ACM in the performance of maintenance
activities.
EPA estimates that "friable" (easily
crumbled) ACM can be found in an esti-
mated 700,000 public and commercial
buildings. About 500,000 of those build-
ings are believed to contain at least some
damaged asbestos. Significantly damaged
ACM is found primarily in building areas
not generally accessible to the public, such
as boiler and mechanical rooms, where
asbestos exposures generally would be
limited to service and maintenance work-
ers. However, if friable ACM is present in
air plenums, it can be distributed through-
out the building, thereby possibly exposing
building occupants.
When is asbestos a problem? Intact and
undisturbed asbestos materials do not
pose a health risk. The mere presence of
asbestos in a building does not mean that
the health of building occupants is endan-
gered. ACM which is in good condition,
and is not damaged or disturbed, is not
likely to release asbestos fibers into the air.
When ACM is prpperiy managed, release
of asbestos fibers into the air is reducedj
and the risk of asbestos-related disease is
thereby correspondingly reduced.
There are a number of guidelines and
regulations that govern asbestos exposure.
Occupational standards for preventing
asbestos-related diseases are recommended
by NIOSH and promulgated by OSHA.
NIOSH guidance contains Recommended
Exposure Limits (RELs) and OSHA
standards set Permissible Exposure Limits
(PELs). The standards also contain many
other measures, such as surveillance,
medical screening, analytical methods, and
methods of control. OSHA regulations
and the EPA Worker Protection Rule also
provide guidance on day-to-day activities
that may bring workers in contact with
ACM. EPA National Emission Standards
for Hazardous Air Pollutants (NESHAP)
define acceptable practices for renovation
and demolition activities that involve as-
bestos-containing materials. In addition,
many States have set exposure standards
and other regulations concerning asbestos.
Asbestos 147
-------
OSHA requires that signs
be posted around areas
where work is being done
that involves damaged
asbestos-containing
materials. These signs
must communicate specific
types of information.
EPA and NIOSH recommend a practical
approach that protects public health by
emphasizing that ACM in buildings should
be identified and appropriately managed,
and that those workers who might disturb
it should be properly trained and protected.
EPA AND NIOSH
POSITIONS ON ASBESTOS
In an effort to calm unwarranted fears that
a number of people seem to have about the
mere presence of asbestos in their build-
ings and to discourage the decisions by
some building owners to remove all ACM
regardless of its condition, the EPA Ad-
ministrator issued an Advisory to the Pub-
lic on Asbestos in Buildings in 1991. This
advisory summarized EPA's policies for
asbestos control in the presentation of the
following "five facts":
Although asbestos is hazardous, the risk
of asbestos-related disease depends upon
exposure to airborne asbestos fibers.
Based upon available data, the average
airborne asbestos levels in buildings
seem to be very low. Accordingly, the
health risk to most building occupants
also appears to be very low.
Removal is often not a building owner's
DANGER
Asbestos
Cancer and Lung Disease Hazard
Authorized Personnel Only
Respirators and Protective
Clothing Are Required in This Area
best course of action to reduce asbestos
exposure. In fact, an improper removal
can create a dangerous situation where
none previously existed.
EPA only requires asbestos removal in
order to prevent significant public expo-
sure to airborne asbestos fibers during
building demolition or renovation
activities.
EPA does recommend a pro-active, in-
place management program whenever
asbestos-containing material is
discovered.
NIOSH's position on asbestos exposure
has been expressed in NIOSH policy state-
ments and internal reports and at OSHA
public hearings:
NIOSH recommends the goal of elimi-
nating asbestos exposure in the work-
place. Where exposures cannot be elimi-
nated, exposures should be limited to the
lowest concentration possible.
NIOSH contends that there is no safe
airborne fiber concentration for asbestos.
NIOSH therefore believes that any de-
tectable concentration of asbestos in the
workplace warrants further evaluation
and, if necessary, the implementation of
measures to reduce exposures.
NIOSH contends that there is no scien-
tific basis to support differentiating
health risks between types of asbestos
fibers for regulatory purposes.
Copies of the EPA and NIOSH policy
statements and public advisories are avail-
able, respectively, from those agencies.
See the last section in this appendix and
Appendix G for information on how to
obtain them.
148 Appendix D
-------
PROGRAMS FOR MANAGING
ASBESTOS IN-PLACE
In some cases, an asbestos operations and
maintenance program is more appropriate
than other asbestos control strategies, in-
cluding removal. Proper asbestos manage-
ment is neither to rip it all out in a panic nor
to ignore the problem under the false pre-
sumption that asbestos is "risk free."
Health concerns remain, particularly for
custodial and maintenance workers.
In-place management does not mean "do
nothing." It means having a program to
ensure lhat the day-to-day management of
the building is carried out in a manner that
minimizes release of asbestos fibers into the
air, and that ensures that when asbestos
fibers are released, either accidentally or
intentionally, proper control and clean-up
procedures are implemented. Such a pro-
gram may be all that is .necessary to control
the release of asbestos fibers until the as-
bestos-containing material in a building is
scheduled to be disturbed by renovation or
demolition activities.
The first responsibility of a building
owner or manager is to identify asbestos-
containing materials, through a building-
wide inventory or on a case-by-case basis,
before suspect materials are disturbed by
renovations or other actions. The Asbestos
Hazard Emergency Response Act
(AHERA) program requires that in schools
an inventory of asbestos materials be done
by properly accredited individuals. Starting
in late 1991 or 1992, there will also be a
requirement that if an inventory of asbestos
materials is done in public and commercial
buildings, the inventory must be done by
properly accredited individuals. In public
and commercial buildings facing major
renovations or demolition, inspections for
the presence of ACM are required, accord-
ing to the 1990 revision of the EPA Asbes-
tos NESHAP. A carefully designed air
monitoring program can be used as an ad-
junct to visual and physical evaluations of
the asbestos-containing materials.
After the material is identified, the build-
ing management and staff can then insti-
tute controls to ensure that the day-to-day
management of the building is carried out
in a manner that prevents or minimizes the
release of asbestos fibers into the air.
These controls will ensure that when as-
bestos fibers are released, either acciden-
tally or intentionally, proper management
and clean-up procedures are implemented.
Another concern of EPA, NIOSH, and
other Federal, State, and local agencies that
are concerned with asbestos and public
health is to ensure proper worker training
and protection. In the course of their daily
activities, maintenance and service work-
ers in buildings may disturb materials and
thereby elevate asbestos fiber levels and
asbestos exposure, especially for them-
selves, if they are not properly trained and
protected. For these persons, risk may be
significantly higher than for other building
occupants. Proper worker training and
protection, as part of an active in-place
management program, can reduce any
unnecessary asbestos exposure for these
workers and others. AHERA requires this
training for school employees whose job
activities may result in asbestos distur-
bances.
In addition to the steps outlined above,
an in-place management program will
usually include notification to workers and
occupants of the existence of asbestos in
their building, periodic surveillance of the
material, and proper recordkeeping. EPA
requires all of these activities for schools
and strongly recommends that other build-
ing owners also establish comprehensive
asbestos management programs. Without
such programs, asbestos materials could be
damaged or could deteriorate, which might
result in elevated levels of airborne asbes-
tos fibers. While the management costs of
all the above activities will depend upon
the amount, condition, and location of the
materials, such a program need not be
expensive.
Asbestos 149
-------
WHERE TO GO FOR
ADDITIONAL INFORMATION
For guidance on asbestos, building owners
and managers are urged to become familiar
with two EPA documents: Managing
Asbestos in Place (published in 1990 and
also known as the "Green Book") and
Guidance for Controlling Asbestos-Con-
taining Materials in Buildings (published
Jn 1985 and also known as the "Purple
Book").
To obtain copies of the guidance publi-
cations and other materials mentioned
above, or to get additional information on
technical issues, call or write:
Environmental Assistance Division
Office of Toxic Substances
U.S. EPA (TS-799)
401 M Street SW
Washington, DC 20460
Telephone (TSCA Information Hotline):
202-554-1404
National Institute for Occupational
Safety and Health
Technical Information Branch
4676 Columbia Parkway
Cincinnati, OH 45226
Telephone: 1-800-35-NIOSH or
1-800-356-4674
Contact State air pollution control or health
agencies for information on pertinent State
activities and regulations. To find an as-
bestos contact in State agencies, consult
the EPA Directory of State Indoor Air
Contacts. For a more complete listing of
publications concerning asbestos, refer to
Appendix G.
150 AppendixD
-------
Appendix E: Radon
lปadon is a radioactive gas .produced by
the decay of radium. It occurs naturally in
almost all soil and rock. Radon migrates
through the soil and groundwater and can
enter buildings through cracks or other
openings in their foundations. Radon's
decay products can cause lung cancer, and
radon is second only to smoking as a cause
of lung cancer in America,
Based on early data, the EPA concen-
trated its radon reduction efforts on one-
and two- family homes. Citing results
from a radon survey conducted jointly
with 25 States, the EPA and the Surgeon
General's office issued a National Health
Advisory that called for testing most
homes for the presence of radon. Ex-
tensive research and case studies in the
field have demonstrated practical remed-
iation methods that typically reduce the
indoor radon concentrations below 4 pQ/L,
the current EPA action level for all occu-
pied buildings.
Now that EPA technical guidance is
being successfully used to reduce human
health risk in homes, the EPA is emphasiz-
ing the development of radon measure-
ment, mitigation, and prevention tech-
niques for schools and large buildings.
Preliminary data from a nationwide survey
of Federal buildings indicates that radon
will probably not be as widespread a prob-
lem in large buildings as it is in homes.
One of the major factors for this difference
is that muM-story buildings have propor-
tionally less space in direct contact with
the earth when compared to homes.
Some of the control technologies utilized
for homes are being studied for their ap-
propriateness to other building types, in-
cluding schools and large buildings. In
addition, new methods and technologies are
being developed to ensure a practical and
cost-effective reduction of radon in these
buildings. As a result, published docu-
ments on guidance and protocols for mea-
surement and remediation of radon hi large
buildings are not currently available.
This publication provides an overview of
radon issues, and should be used only as
background information. For more infor-
mation, refer to other sources of informa-
tion that are specific to radon in indoor air.
BUILDING MEASUREMENT,
DIAGNOSIS, AND REMEDIATION
Protocols specific to the measurement of
radon and radon progeny in large buildings
are tentatively scheduled to be published by
EPA in early 1992. These large building
measurement protocols can assist skilled
building owners or facility personnel in
making initial screening tests for the
presence of radon. A new protocol specific
to large buildings is necessary due to the
major differences in building dynamics,
HVAC systems, and occupancy patterns
between large buildings and homes, and
how these impact radon.
As part of its effort to develop wide-
spread State and private sector capabilities,
the EPA established a voluntary proficiency
program (Radon Measurement Proficiency
Program) for radon laboratories and com-
mercial measurement firms. A State Profi-
ciency Report (EPA 520/1-91-014), which
gives information on specific radon mea-
surement firms in your area, can be ob-
tained from your State radon office or from
your EPA Regional Office.
Radon 151
-------
Three elements must be present for
radon to be a problem: a radon source, a
pathway that allows radon to enter the
building, and a driving force that causes
the radon to flow through the pathway and
into the building. Preventing radon from
entering the building is always desirable
compared with mitigation after radon has
entered. The reduction of pathways and
driving forces are therefore usually the
focus of attention during diagnostic and
remediation efforts.
WHERE TO GO FOR
ADDITIONAL INFORMATION
Due to the diversity and complexity of
large buildings, and because the research
and development of appropriate radon
remediation technologies for these struc-
tures are in the early phases, generalized
building diagnostic and remediation meth-
odologies are not yet available. For assis-
tance, please contact the appropriate orga-
nizations on the following list or a profes-
sional engineering firm or mitigation com-
pany with experience in this matter.
State Radon Offices
There are several ways to get the name of a
contact person in your State radon office or
information about that office. You can call
the radon contact in the EPA Regional
Office for your state or you can order the
Directory of State Indoor Air Contacts
from the EPA Public Information Center.
(See list of IAQ and radon contacts and list
of EPA publications in Appendix G.)
Regional Radon Training Centers
As part of its effort to develop State and
private sector capabilities for radon reduc-
tion, the EPA has coordinated the forma-
tion of four Regional Radon Training
Centers (RRTCs). The RRTCs provide a
range of radon training and proficiency
examination courses to the public for a fee.
Eastern Regional Radon
Training Center
Rutgers, The State University
Livingston Campus, Building 4087
New Brunswick, NJ 08903-0231
908-932-2582
Mid-West Universities
Radon Consortium
University of Minnesota
1985 Buford Avenue (240)
St. Paul, MN 55108-6136
612-624-8747
Western Regional Radon
Training Center
Guggenheim Hall
Colorado State University
Fort Collins, CO 80523
1-800-462-7459/303-491-7742
Southern Regional Radon
Training Center
Auburn University
Housing Research Center
Harbert Engineering Center
Auburn University, AL 36849-5337
205-844-6261
EPA Regional Offices
If you want additional information from
EPA regarding radon, start with the EPA
Regional Offices. Telephone numbers
for radon information contacts are given
in the list of EPA Regional Offices in
Appendix G of this publication,
EPA Radon Division
If information is unavailable from the
above sources, please contact the EPA
Radon Division at:
Radon Division (ANR-464)
U.S. EPA
401 M Street, SW
Washington, DC 20460
202-260-9605
152 Appendix E
-------
Appendix F; Glossary and Acronyms
ACGIH American Conference of
Governmental Industrial Hygienists.
ASHRAE American Society of
Heating, Refrigerating, and Air-CondMon-
ing Engineers.
ASTM American Society for Testing
and Materials.
Air Cleaning An IAQ control strategy
to remove various airborne particulates
and/or gases from the air. The three types
of air cleaning most commonly used are
paniculate filtration, electrostatic precipita-
tion, and gas sorption.
Air Exchange RateUsed in two ways:
1) the number of times that the outdoor air
replaces the volume of air in a building per
unit time, typically expressed as air
changes per hour, 2) the number of times
that the ventilation system replaces the air
within a room or area within the building.
Antimicrobial Agent that kills micro-
bial growth. See "disinfectant," "sani-
tizer," and "sterilizer."
BRI See "Building-Related Illness."
Biological Contaminants Agents
derived from or that are living organisms
(e,g., viruses, bacteria, fungi, and mammal
and bird antigens) that can be inhaled and
can cause many types of health effects
including allergic reactions, respiratory
disorders, hypersensitivity diseases, and
infectious diseases. Also referred to as
"microbiologicals" or "microbials."
Breathing Zone Area of a room in
which occupants breathe as they stand, sit,
or lie down.
Building Envelope Elements of the
building, including all external building
materials, windows, and walls, that enclose
the internal space.
Building-Related Illness Diagnosable
illness whose symptoms can be identified
and whose cause can be directly attributed
to airborne building pollutants (e.g.,
Legionnaire's disease, hypersensitivity
pneumonitis).
CFM Cubic feet per minute.
CO Carbon monoxide.
CO2 Carbon dioxide.
Ceiling Plenum Space below the
flooring and above the suspended ceiling
that accommodates the mechanical and
electrical equipment and that is used as
part of the air distribution system. The
space is kept under negative pressure.
Commissioning Start-up of a building
that includes testing and adjusting HVAC,
electrical, plumbing, and other systems to
assure proper functioning and adherence to
design criteria. Cornmissioning also
includes the instruction of building
representatives in the use of the building
systems.
Conditioned Air Air that has been
heated, cooled, humidified, or dehumidi-
fied to maintain an interior space within
the "comfort zone." (Sometimes referred to
as "tempered" air.)
Constant Air Volume System Air
handling system that provides a constant
air flow while varying the temperature to
meet heating and cooling needs.
Dampers Controls that vary airflow
through an air outlet, inlet, or duct. A
damper position may be immovable,
manually adjustable, or part of an auto-
mated control system.
Glossary and Acronyms 153
-------
Diffusers and Grilles Components of
the ventilation system that distribute and
diffuse air to promote air circulation in the
occupied space. Diffusers supply air and
grilles return air.
Disinfectants One of three groups of
antimicrobials registered by EPA for
public health uses. EPA considers an
antimicrobial to be a disinfectant when it
destroys or irreversibly inactivates
infectious or other undesirable organisms,
but not necessarily their spores. EPA
registers three types of disinfectant
products based upon submitted efficacy
data: limited, general or broad spectrum,
and hospital disinfectant.
EPA United States Environmental
Protection Agency.
ETS Environmental tobacco smoke.
Environmental Factors Conditions
other than indoor air contaminants that
cause stress, comfort, and/or health
problems (e.g., humidity extremes, drafts,
lack of air circulation, noise, and over-
crowding).
Ergonomics Applied science that
investigates the impact of people's
physical environment on their health and
comfort (e.g., determining the proper chair
height for computer operators).
Exhaust Ventilation Mechanical
removal of air from a portion of a building
(e.g., piece of equipment, room, or general
area).
Gas Sorption Devices used to reduce
levels of airborne gaseous compounds by
passing the air through materials that
extract the gases. The performance of
solid sorbents is dependent on the airflow
rate, concentration of the pollutants,
presence of other gases or vapors, and
other factors.
HEPA High efficiency particulate
arrestance (filters).
HVAC Heating, ventilation, and air-
conditioning system.
Hypersensitivity Diseases Diseases
characterized by allergic responses to
animal antigens. The hypersensitivity
diseases most clearly associated with
indoor air quality are asthma, rhinitis, and
hypersensitivity pneumonitis. Hypersensi-
tivity pneumonitis is a rare but serious
disease that involves progressive lung
damage as long as there is exposure to the
causative agent.
IAQ Indoor air quality.
IPM Integrated pest management.
Indicator Compounds Chemical
compounds, such as carbon dioxide, whose
presence at certain concentrations may be
used to estimate certain building condi-
tions (e.g., airflow, presence of sources).
MCS See "Multiple Chemical Sensitiv-
ity."
MSDS Material Safety Data Sheet.
Make-up Air Air brought into a
building from outdoors through the
ventilation system and that has not been
previously circulated through the system.
Microbiologicals See "Biological
Contaminants."
Multiple Chemical Sensitivity A term
used by some people to refer to a condition
in which a person is considered to be
sensitive to a number of chemicals at very
low concentrations. There are a number of
views about the existence, potential causes,
and possible remedial actions regarding
this phenomenon.
NIOSH National Institute for Occupa-
tional Safety and Health.
NTIS National Technical Information
Service.
Negative Pressure Condition that
exists when less air is supplied to a space
than is exhausted from the space, so the air
pressure within that space is less than that
in surrounding areas.
OSHA Occupational Safety and Health
Administration.
154 Appendix F
-------
PELs Permissible Exposure Limits
(standards set by OSHA).
PM Preventive Maintenance.
Plenum Air compartment connected to
a duct or ducts.
Positive Pressure Condition that exists
when more air is supplied to a space than
is exhausted, so the air pressure within that
space is greater than that in surrounding
areas.
Psychosocial Factors Psychological,
organizational, and personal stressors that
could produce symptoms similar to poor
indoor air quality.
RELs Recommended Exposure Limits
(recommendations made by NIOSH).
Radiant Heat TransferRadiant heat
transfer occurs when there is a large differ-
ence between the temperatures of two
surfaces that are exposed to each other, but
are not touching.
Re-entrainment Situation that occurs
when the air being exhausted from a build-
ing is immediately brought back into the
system through the air intake and other
openings in the building envelope,
SBS See "Sick Building Syndrome."
Sanitizer One of three groups of anti-
microbials registered by EPA for public
health uses. EPA considers an antimicro-
bial to be a sanitizer when it reduces but
does not necessarily eliminate all the mi-
croorganisms on a treated surface. To be a
registered sanitizer, the test results for a
product must show a reduction of at least
99.9% in the number of each test microor-
ganism over the parallel control.
Short-circuiting Situation that occurs
when the supply air flows to exhaust regis-
ters before entering the breathing zone. To
avoid short-circuiting, the supply air must
be delivered at a temperature and velocity
that results in mixing throughout the space,
Sick Building SyndromeTerm some-
times used to describe situations in which
building occupants experience acute health
and/or comfort effects that appear to be
linked to time spent in a particular build-
ing, but where no specific illness or cause
can be identified. The complaints may be
localized hi a particular room or zone, or
may be spread throughout the building.
Soil Gases Gases that enter a building
from the surrounding pound (e.g., radon,
volatile organics, pesticides).
Stack Effect Pressure-driven airflow
produced by convection as heated air rises,
creating a positive pressure area at the top
of a building and a negative pressure area
at the bottom of a building. The stack
effect can overpower the mechanical sys-
tem and disrupt ventilation and circulation
in a building.
Static Pressure Condition that exists
when an equal amount of air is supplied to
and exhausted from a space. At static
pressure, equilibrium has been reached. ,
Sterilizer One of three groups of anti-
microbials registered by EPA for public
health uses. EPA considers an antimicro-
bial to be a sterilizer when it destroys or
eliminates all forms of bacteria, fungi,
viruses, and their spores. Because spores
are considered the most difficult form of a
microorganism to destroy, EPA considers
the term sporicide to be synonymous with
"sterilizer."
TLVs Threshold Limit Values (guide-
lines recommended by ACGIH).
TVOCs Total volatile organic com-
pounds.
Tracer Gases Compounds, such as
sulfur hexafluoride, which are used to
identify suspected pollutant pathways and
to quantify ventilation rates. Tracer gases
may be detected qualitatively by their odor
or quantitatively by air monitoring equip-
ment.
VAV Variable air volume system.
VOCs See "Volatile Organic Com-
pounds."
Glossary and Acronyms 155
-------
Variable Air Volume System Air
handling system that conditions the air to a
constant temperature and varies the outside
airflow to ensure thermal comfort.
Ventilation Air Defined as the total air,
which is a combination of the air brought
into the system from the outdoors and the
air that is being recirculated within the
building. Sometimes, however, used in
reference only to the air brought into the
system from the outdoors,
Volatile Organic Compounds (VOCs)
Compounds that evaporate from the many
housekeeping, maintenance, and building
products made with organic chemicals.
These compounds are released from
products that are being used and that are in
storage. In sufficient quantities, VOCs can
cause eye, nose, and throat irritations,
headaches, dizziness, visual disorders,
memory impairment; some are known to
cause cancer in animals; some are sus-
pected of causing, or are known to cause,
cancer hi humans. At present, not much is
known about what health effects occur at
the levels of VOCs typically found in
public and commercial buildings.
WHO World Health Organization.
156 Appendix F
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Appendix G: Resources
FEDERAL AGENCIES WITH
MAJOR INDOOR AIR
RESPONSIBILITY FOR PUBLIC
AND COMMERCIAL BUILDINGS
U.S. Environmental
Protection Agency
Conducts a non-regulatory indoor air
quality program that emphasizes research,
information dissemination, technical
guidance, and training. Issues regulations
and carries out other activities that affect
indoor air quality under the laws for
pesticides, toxic substances, and drinking
water.
Public Information Center
(PM-211B)
401 M Street, SW
Washington, DC 20460
202-260-2080
Distributes indoor air quality
publications.
National Pesticides Telecommunications
Network National toll-free number:
1-800-858-PEST
In Texas: 806-743-3091
Provides information on pesticides.
TSCA Hotline Service
202-554-1404
Provides information on asbestos and
other toxic substances.
Occupational Safety and Health
Administration
Promulgates safety and health standards,
facilitates training and consultation, and
enforces regulations to ensure that
workers are provided with safe and
healthful working conditions. (For further
information contact OSHA Regional
Offices.)
National Institute for
Occupational Safety and Health
Conducts research, recommends standards
to the U.S. Department of Labor, and
conducts training on various issues
including indoor air quality to promote
safe and healthful workplaces. Undertakes
investigations at request of employees,
employers, other federal agencies, and
state and local agencies to identify and
mitigate workplace problems.
Requests for Field Investigations
NIOSH
Hazard Evaluations and Technical
Assistance Branch (R-9)
4676 Columbia Parkway
Cincinnati, OH 45226
513-841-4382
Requests for Information:
1-800-35-NIOSH
or 1-800-356-4674
Resources 157
-------
EPA Regional Offices
Address inquiries to the contacts in the
EPA Regional Offices at the following
addresses:
(CTปME,MA,NH,RI,VT)
EPA Region 1
John F. Kennedy Federal Building
Boston, MA 02203
617-565-3232 (indoor air)
617-565-4502 (radon)
617-565-3744 (asbestos)
617-565-3265 (NESHAP)
(NJ,NY,PR,VI)
EPA Region 2
26 Federal Plaza
New York, NY 10278
212-264-4410 (indoor air)
212-264-4410 (radon)
212-264-6671 (asbestos)
212-264-6770 (NESHAP)
(DE,DC,MD,PA,VAปWV)
EPA Region 3
841 Chestnut Building
Philadelphia, PA 19107
215-597-8322 (indoor air)
215-597-4084 (radon)
215-597-3160 (asbestos)
215-597-1970 (NESHAP)
(AL,FL,GA,KY,MS,NC,Se,TN)
EPA Region 4
345 Courtland Street, NE
Atlanta, GA 30365
404-347-2864 (indoor air)
404-347-3907 (radon)
404-347-5014 (asbestos)
404-347-5014 (NESHAP)
(IL,IN,MI,MN,OH,WI)
EPA Region 5
230 South Dearborn Street
Chicago, IL 60604
Region 5 Environmental Hotline:
1-800-572-2515 (IL)
1-800-621-8431 (IN, MI, MN, OH, WI)
312-886-7930 (outside Region 5)
(AR,LA,NM,OK,TX)
EPA Region 6
1445 Ross Avenue
Dallas, TX 75202-2733
214-655-7223 (indoor air)
214-655-7223 (radon)
214-655-7223 (asbestos)
214-655-7223 (NESHAP)
(IA,KS,MO,NE)
EPA Region 7
726 Minnesota Avenue
Kansas City, KS 66101
913-551-7020 (indoor air)
913-551-7020 (radon)
913-551-7020 (asbestos)
913-551-7020 (NESHAP)
(CO,MT,ND,SD,UT,WY)
EPA Region 8
999 18th Street Suite 500
Denver, CO 80202-2405
303-293-1440 (indoor air)
303-293-0988 (radon)
303-293-1442 (asbestos)
303-294-7611 (NESHAP)
(AZ,CA,HI,NV,AS,GU)
EPA Region 9
75 Hawthorne Street, A-l-1
San Francisco, CA 94105
415-744.1133 (indoor air)
415-744-1045 (radon)
415-744-1136 (asbestos)
415-744-1135 (NESHAP)
(AK,ID,OR,WA)
EPA Region 10
1200 Sixth Avenue
Seattle, WA 98101
206-553-2589 (indoor air)
206-553-7299 (radon)
206-553-4762 (asbestos)
206-553-1757 (NESHAP)
158 Appendix G
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OSHA Regional Offices
(CT,ME,MA,NH,RI,VT)
OSHA Region 1
133 Portland Street, 1st Floor
Boston, MA 02114
617-565-7164
(NJ,NY,PR,VI)
OSHA Region 2
210 Varick Street, Room 670
New York, NY 10014
212-337-2376
(DE,DC,MD,PA,VA,WV)
OSHA Region 3
Gateway Building, Suite 2100
3535 Market Street
Philadelphia, PA 19104
215-596-1201
(AL,FL,GA,KY,MS,NC,SC,TN)
OSHA Region 4
1375 Peachtree Street, NE, Suite 587
Atlanta, GA 30367
404-347-3573
(IL,IN,MI,MN,OH,WI)
OSHA Region 5
230 South Dearborn Street, Room 3244
Chicago, EL 60604
312-353-2220
(AR,LA,NM,OK,TX)
OSHA Region 6
525 Griffin Street, Room 602
Dallas, TX 75202
214-767-4731
(IA,KS,MO,NE)
OSHA Region 7
911 Walnut Street, Room 406
Kansas City, MO 64106
816-426-5861
(CO,MT,ND,SD,UT,WY)
OSHA Region 8
Federal Building, Room 1576
1961 Stout Street
Denver, CO 80294
303-844-3061
(AZ,CA,HI,NV,AS,GU)
OSHA Region 9
71 Stevenson Street, 4th Floor
San Francisco, CA 94105
415-744-6570
(AK,ID,OR,WA)
OSHA Region 10
1111 Third Avenue, Suite 715
Seattle, WA 98101-3212
206-442-5930
Resources 159
-------
OTHER FEDERAL AGENCIES
WITH INDOOR AIR
RESPONSIBILITIES
Bonneville Power Administration
P.O. Box 3621-RMRD
Portland, OR 97208
503-230-5475
Provides radon-resistant construction
techniques, source control, and removal
technology for indoor air pollutants.
Consumer Product Safety Commission
5401 Westbard Avenue
Bethesda, MD 20207
1-800-638-CPSC
Reviews complaints regarding the safety of
consumer products and takes action to
ensure product safety.
General Services Administration
18th and F Streets, NW
Washington, DC 20405
202-501-1464
Writes indoor air quality policy for Federal
buildings. Provides proactive indoor air
quality building assessments. Assesses
complaints and provides remedial action.
U.S. Department of Energy
Office of Conservation and Renewable
Energy
1000 Independence Avenue, SW, CE-43
Washington, DC 20585
202-586-9455
Quantifies the relationship among reduced
infiltration, adequate ventilation, and ac-
ceptable indoor air quality.
U.S. Department of Health and Human
Services
Office on Smoking and Health
National Center for Chronic Disease
Prevention and Health Promotion
Centers for Disease Control
1600 Clifton Road, NE
Mail Stop K50
Atlanta, GA 30333
404-488-5705
Disseminates information about the health
effects of passive smoking and strategies
for eliminating exposure to environmental
tobacco smoke.
Tennessee Valley Authority
Occupational Hygiene Department
328 Multipurpose Building
Muscle Shoals, AL 35660
205-386-2314
Provides building surveys and assessments
associated with employee indoor air
quality complaints.
STATE AND LOCAL AGENCIES
Your questions and concerns about indoor
air problems can frequently be answered
most readily by the government agencies
in your State or locality. Responsibilities
for indoor air quality issues are usually
divided among many different agencies.
You will often find that calling or writing
the agencies responsible for health or air
quality control is the best way to start
getting information from your State or
local government. The EPA and Public
Health Foundation publication, Directory
of State Indoor Air Contacts, lists State
agency contacts. (See publications list for
information on ordering this publication.)
160 Appendix G
-------
PRIVATE SECTOR CONTACTS
The private sector organizations that have
information for the public on indoor air
quality issues in commercial and public
buildings include the following:
Building Management
Associations
Association of Physical Plant Adminis-
trators of Universities and Colleges
1446 Duke Street
Alexandria, VA 22314-3492*
703-684-1446
Building Owners and Managers
Association International
1201 New York Ave., NW, Suite 300
Washington, DC 20005
202-408-2684
Institute of Real Estate Management
430 North Michigan Avenue
Chicago, IL 60611
312-661-1930
International Council of Shopping
Centers
1199 North Fairfax Street, Suite 204
Alexandria, VA 22314
703-549-7404
International Facilities Management
Association
Summit Tower, Suite 1710
11 Greenway Plaza
Houston, TX 77046
713-623-4362
National Apartment Association
1111 14th Street, NW, Suite 900
Washington, DC 20005
202-842-4050
National Association of Industrial and
Office Parks
1215 Jefferson Davis Highway, Suite 100
Arlington, VA 22202
703-979-3400
Professional and Standard
Setting Organizations
Air and Waste Management Association
P.O. Box 2861
Pittsburgh, PA 15230
412-232-3444
Air-Conditioning and Refrigeration
Institute
1501 Wilson Blvd., Suite 600
Arlington, VA
703-524-8800
American Conference of Governmental
Industrial Hygienists
6500 Glenway Avenue, Building D-7
Cincinnati, OH 45211
513-661-7881
American Industrial Hygiene
Association
P.O. Box 8390
345 White Pond Drive
Akron, OH 44320
216-873-2442
American Society for Testing and
Materials
1916 Race Street
Philadelphia, PA 19103
215-299-5571
American Society of Heating,
Refrigerating, and Air-Conditioning
Engineers
1791 Tullie Circle, NB
Atlanta, GA 30329
404-636-8400
National Conference of States on
Building Codes and Standards, Inc.
505 Huntmar Park Drive, Suite 210
Herndon, VA 22070
703-437-0100
Resources 161
-------
Product Manufacturers
Adhesive and Sealant Council
1627 K Street, NW, Suite 1000
Washington, DC 20006-1707
202-452-1500
Asbestos Information Association
1745 Jefferson Davis Highway, Room 509
Arlington, VA 22202
703-979-1150
Business Council on Indoor Air Quality
1225 19th Street, Suite 300
Washington, DC 20036
202-775-5887
Carpet and Rug Institute
310 Holiday Avenue
Dalton.GA 30720
404-278-3176
Chemical Specialties Manufacturers
Association
19131 Street, NW
Washington, DC 20006
202-872-8110
Electric Power Research Institute
P.O. Box 10412
Palo Alto, CA 94303
415-855-2902
Formaldehyde Institute, Inc.
1330 Connecticut Avenue, NW
Washington, DC 20036
202-822-6757
Foundation of Wall and Ceiling
Industries
1600 Cameron Street
Alexandria, VA 22314-2705
703-548-0374
Gas Research Institute
8600 West Bryn Mawr Avenue
Chicago, IL 60631
312-399-8304
National Paint and Coatings Association
1500 Rhode Island Avenue, NW
Washington, DC 20005
202-462-6272
Thermal Insulation Manufacturers
Association Technical Services
Air Handling Committee
1420 King Street
Alexandria, VA 22314
(703) 684-0474
Building Service Associations
Air-Conditioning and Refrigeration
Institute
1501 Wilson Boulevard, 6th floor
Arlington, VA 22209
703-524-8800
Air-Conditioning Contractors of
America
1513 16th Street, NW
Washington DC 20036
202-483-9370
American Consulting Engineers Council
1015 15th Street, NW, Suite 802
Washington, DC 20005
202-347-7474
Associated Air Balance Council
1518 K Street, NW
Washington, DC 20005
202-737-0202
Association of Energy Engineers
4025 Pleasantdale Rd., Suite 420
Atlanta, GA 30340
404-447-5083
Association of Specialists in Cleaning
and Restoration International
10830 Annapolis Junction Road, Suite 312
Annapolis Junction, MD 20701
301-604-4411
National Air Duct Cleaners Association
1518 K Street, NW, Suite 503
Washington, DC 20005
202-737-2926
National Association of Power Engineers
3436 Haines Way, Suite 101
Falls Church, VA 22041
703-845-7055
162 Appendix G
-------
National Energy Management Institute
601 North Fairfax Street, Suite 160
Alexandria, VA 22314
703-739-7100
National Environmental Balancing
Bureau
1385 Piccard Drive
Rockville,MD 20850
301-977-3698
National Pest Control Association
8100 Oak Street
Dunn Loring, VA 22027
703-573-8330
Sheet Metal and Air Conditioning
Contractors National Association
4201 LaFayette Center Drive
Chantilly, VA 22021
703-803-2980 '
Unions
AFL-CIO
Department of Occupational Safety and
Health
815 16th Street, NW
Washington, DC 20006
202-637-5000
American Federation of Government
Employees
80 F Street, NW
Washington, DC 20001
202-737-8700
American Federation of State, County,
and Municipal Employees
1625 L Street, NW
Washington, DC 20036
(202) 429-1215
American Federation of Teachers
555 New Jersey Avenue, NW
Washington, DC 20001
202-879-4400
Communication Workers of America
501 3rd Street, NW
Washington, DC 20001
202-434-1160
International Union of Operating
Engineers
1125 17th Street, NW
Washington, DC 20036
202-429-9100
Service Employees International Union
1313 L Street, NW
Washington, DC 20005
Environmental/Health/
Consumer Organizations
American Academy of Allergy and
Immunology
611 East Wells Street
Milwaukee, WI 53202 .- - -
414-272-6071
American Lung Association
or your local lung association
1740 Broadway
New York, NY 10019
Consumer Federation of America
1424 16th Street, NW, Suite 604
Washington, DC 20036
National Center for Environmental
Health Strategies
1100 Rural Avenue
Voorhees,NJ 08043
609-429-5358
National Environmental Health
Association
720 South Colorado Blvd.
South Tower, Suite 970
Denver, CO 80222
303-756-9090
National Foundation for the Chemically
Hypersensitive
P.O. Box 9
Wrightsville Beach, NC 28480
517-697-3989 ' . ,
Occupational Health Foundation
1126 16th Street, NW
Washington, DC 20036
202-842-7840
Resources 163
-------
PUBLICATIONS
Items marked * are available from EPA
Public Information Center (PM-211B),
401 M Street, SW, Washington, DC
20460. 202-260-2080.
Items marked ** are available from TSCA
Assistance Hotline (TS-799), 401 M
Street, SW, Washington, DC 20460.
202-554-1404.
Items marked*** are available from
NIOSH Publications Dissemination,
4676 Columbia Parkway, Cincinnati, OH
45202. 513-533-8287.
General Information
Cone, James E. and Michael J. Hodgson,
MD, MPH. Problem Buildings: Build-
ing-Associated Illness and the Sick
Building Syndrome. 1989. From the
series: "Occupational Medicine: State of
the Art Reviews." Hanley & Belfus, Inc.,
210 South 13th Street, Philadelphia, PA
19107.
Godish, Thad. Indoor Air Pollution
Control 1989. Lewis Publishers, 121
South Main Street, Chelsea, MI 48118.
Rajhans, G.S., Report of the Inter-
ministerial Committee on Indoor Air
Quality, 1988. Contact: G. Rajhans,
Health and Safety Support Services
Branch, Ministry of Labour, 400 Univer-
sity Avenue, 7th Floor, Toronto, Ontario,
Canada M7A 1T7.
Sheet Metal and Air Conditioning
Contractor's National Association, Inc.
(SMACNA). Indoor Air Quality. 1988.
8224 Old Courthouse Road, Vienna,
Virginia 22180.
U.S. Environmental Protection Agency
and the Public Health Foundation. Direc-
tory of State Indoor Air Contacts. Up-
dated, 1991.*
U.S. Environmental Protection Agency.
Designing for Good Indoor Air Quality:
An Introduction for Design Professionals.
(In progress).
U.S. Environmental Protection Agency.
1988. Project Summaries: Indoor Air
Quality in Public Buildings. 1988.
Contains findings of research on IAQ in 10
new public and commercial buildings and
on building material emissions.*
U.S. Environmental Protection Agency
and the U.S. Consumer Product Safety
Commission, The Inside Story: A Guide
to Indoor Air Quality. 1988. Addresses
residential indoor air quality primarily, but
contains a section on offices. *
U.S. Environmental Protection Agency.
Sick Building Syndrome. Indoor Air
Quality Fact Sheet #4. Revised, 1991.*
U.S. Environmental Protection Agency.
Ventilation and Air Quality in Offices.
Indoor Air Quality Fact Sheet #3.
Revised, 1990.*
World Health Organization. Air Quality
Guidelines for Europe. 1987. WHO
Regional Publications, European Series No.
23. Available from WHO Publications
Center USA, 49 Sheridan Avenue, Albany,
NY 12210.
Asbestos
Keyes, Dale L, and Jean Chesson. A Guide
to Monitoring Airborne Asbestos in
Buildings. 1989. Environmental Sciences,
Inc., 105 E. Speedway Blvd., Tucson,
Arizona 85705.
U.S. Department of Health and Human
Services, Public Health Service, U.S.
Centers for Disease Control, National
Institute of Occupational Safety and
Health. Testimony of NIOSH on the
Occupational Safety and Health
Administration's Proposed Rule on
Occupational Exposure to Asbestos,
Tremolite, Anthophylttte, and Actinolite.
164 Appendix G
-------
June 1984, May 1990, and January 1991.
NIOSH Docket Office, C-34,4676 Colum-
bia Parkway, Cincinnati, OH 45226,
U.S. Environmental Protection Agency. A
Guide to Respiratory Protection for the
Asbestos Abatement Industry. 1986. EPA
560/OTS 86-001.**
U.S. Environmental Protection Agency.
Abatement of Asbestos-Containing Pipe
Insulation. 1986. Technical Bulletin No.
1986-2. **
U.S. Environmental Protection Agency.
Asbestos Abatement Projects: Worker
Protection. Final Rule 40 CFR. 763.
February 1987. **
U.S. Environmental Protection Agency.
Asbestos Ban and Phaseout Rule. 40 CFR
763.160 to 763.179. Federal Register, July
12,1989. **
U.S. Environmental Protection Agency.
Asbestos in Buildings: Guidance for
Service and Maintenance Personnel (in
English and Spanish). 1985. EPA 560/5-
85-018. ("Custodial Pamphlet"). **
U.S. Environmental Protection Agency.
Asbestos in Buildings: Simplified Sam-
pling Scheme for Surfacing Materials.
1985. 560/5-85-030A. ("Pink Book"). **
U.S. Environmental Protection Agency.
Guidance for Controlling Asbestos-
Containing Materials in Buildings. 1985.
EPA 560/5-85-024. ("Purple Book"). **
U.S. Environmental Protection Agency.
Guidelines for Conducting the AHERA
TEM Clearance Test to Determine
Completion of an Asbestos Abatement
Project, EPA 560/5-89-001. **
U.S. Environmental Protection Agency.
Managing Asbestos In Place: A Building
Owner's Guide to Operations and Mainte-
nance Programs for Asbestos-Containing
Materials. 1990. ("Green Book").**
U.S. Environmental Protection Agency.
Measuring Airborne Asbestos Following
An Abatement Action. 1985. EPA 600/4-
85-049. ("Silver Book"), **
U.S. Environmental Protection Agency.
National Emission Standards for Hazard-
ous Air Pollutants. 40 Code of Federal
Regulation 61. April 1984. **
U.S. Environmental Protection Agency,
Transmission Electron Microscopy
Asbestos Laboratories: Quality Assurance
Guidelines. 1989. EPA 560/5-90-002.**
U.S. Department of Labor. OSHA Regula-
tions. 29 Code of Federal Regulation
1910.1001. General Industry Asbestos
Standard. 29 Code of Federal Regulation
1926.58. Construction Industry Asbestos
Standard. June 1986; amended September
1988. DOL-OSHA Docket, 200 Constitu-
tion Avenue, NW, Room N 2625,
Washington, DC 20210.
U.S. Department of Labor. OSHA Regula-
tions. 29 Code of Federal Regulation
1910.134. Respiratory Protection Stan-
dard. June 1974. DOL-GSHA Docket,
200 Constitution Avenue, NW, Room
N 2625, Washington, DC 20210.
Biologicals
American Council of Governmental Indus-
trial Hygienists. Guidelines for the Assess-
ment of Bioaerosols in the Indoor Envir-
onment. 1989. 6500 Qlenway Avenue,
Building D-7, Cincinnati, OH 45211.
Morey, P., J. Feeley, and J. Otten.
Biological Contaminants in Indoor
Environments. 1990. American Society
for Testing and Materials Publications,
1916 Race Street, Philadelphia, PA 19103.
Building Management,
Investigation, and Remediation
Baierghi, Hani and Catherine Arnoult.
Practical Manual for Good Indoor Air
Quality. 1989. Quebec Association for
Energy Management. 1259 Bern Street,
Suite 510, Montreal, Quebec, Canada, H2L
4C7.
Resources 165
-------
Hansen, Shirley J., Managing Indoor Air
Quality. 1991. Fairmont Press, 700 Indian
Trail, Lilburn, GA 30247.
U.S. Department of Health and Human
Services. Public Health Service. Centers
for Disease Control. National Institute for
Occupational Safety and Health. Indoor
Air Quality: Selected References,
1989.***
U.S. Department of Health and Human
Services. Public Health Service. Centers
for Disease Control. National Institute for
Occupational Safety and Health. Guidance
for Indoor Air Quality Investigations,
1987.***
Weekes, Donald M. and Richard B.
Gammage. The Practitioner's Approach
to Indoor Air Quality Investigations.
Proceedings of the Indoor Air Quality
International Symposium. 1989. American
Industrial Hygiene Association, P.O. Box
8390, Akron Ohio 44320.
Environmental Tobacco Smoke
National Research Council. Environmen-
tal Tobacco Smoke: Measuring Expo-
sures and Assessing Health Effects, 1986.
National Academy Press. 2001 Wisconsin
Avenue, NW, Washington, DC 20418.
U.S. Department of Health and Human
Services. Public Health Service. Office
on Smoking and Health. The Health
Consequences of Involuntary Smoking,
A Report of the Surgeon General. 1986.
1600 Clifton Road, NE (Mail Stop K50)
Atlanta, GA 30333.
U.S. Department of Health and Human
Services. Public Health Service. Centers
for Disease Control. National Institute for
Occupational Safety and Health. Current
Intelligence Bulletin 54: Environmental
Tobacco Smoke in the Workplace
Lung Cancer and Other Health Effects.
DHHS (NIOSH) Publication No. 91-108.
1991,***
U.S. Department of Health and Human
Services. National Cancer Institute.
Office of Cancer Communications. A
series of one-page information sheets on
all.aspects ofsmoMng in the workplace.
For copies, call 1-800-4-GANCER.
U.S. Environmental Protection Agency.
Environmental Tobacco Smoke. Indoor
Air Quality Fact Sheet #5. 1989.*
U.S. Environmental Protection Agency.
Environmental Tobacco Smoke: A Guide
to the Development of Effective Smoking
Policies. (In progress.) *
U.S. Environmental Protection Agency.
Health Effects of Passive Smoking:
Assessment of Lung Cancer in Adults and
Respiratory Disorders in Children. (In
progress.) *
PCBs
U.S. Department of Health and Human
Services, Public Health Service. Centers
for Disease Control. National Institute for
Occupational Safety and Health. Current
Intelligence Bulletin 45: Polychlorinated
Biphenyls Potential Health Hazards
from Electrical Equipment Fires or
Failures. DHHS (NIOSH) Publication
No. 86-111. 1977. Available from the
National Technical Information Service,
5285 Port Royal Road, Springfield, VA
22161.
U.S. Department of Health and Human
Services. Public Health Service. Centers
for Disease Control. National Institute for
Occupational Safety and Health. A
Recommended Standard for Occupational
Exposure to Polychlorinated Biphenyls.
DHHS (NIOSH) Publication No. 77-225.
1977. Available from the National
Technical Information Service, 5285 Port
Royal Road, Springfield, VA 22161.
U.S. Environmental Protection Agency.
Transformers and the Risk of Fire: A
Guide for Building Owners. 1986. OPA/
86-001. **
166 Appendix G
-------
Radon
U.S. Environmental Protection Agency,
State Proficiency Report. 1991. EPA
520/1-91-014. Available from State
radon offices. List of laboratories that
have demonstrated competence in radon
measurement analysis.
Standards and Guidelines
American Conference of Government
Industrial Hygienists. Threshold Limit
Values and Biological Exposure Indices.
1990-1991. 6500 Glenway Avenue,
Building D-7, Cincinnati, OH 45211.
U.S. Department of Health and Human
Services. Public Health Service. Centers
for Disease Control. National Institute for
Occupational Safety and Health, NIOSH
Recommendations for Occupational
Safety and Health, Compendium of
Policy Documents and Statements.
DHHS (NIOSH) Publications 91-109.
1991.***
U.S. Department of Labor. OSHA
Regulations. 29 CFR Part 1910.1000.
OSHA Standards for Air Contaminants.
Available from the U.S. Government
Printing Office, Washington, DC 20402.
202-783-3238. Additional health
standards/or some specific air contami-
nants are also available in Subpart Z.
Ventilation/Thermal Comfort
Brief descriptions of the ASHRAE
standards listed below are included in
Appendix, B, ASHRAE materials are
available from their Publication Sales
Department, 1791 Tullie Circle, NE,
Atlanta, GA 30329. 404-636-8400.
ASHRAE Guideline 1-1989. Guideline
for the Commissioning ofHVAC
Systems. 1989.
ASHRAE Journal. October 1989 Issue.
Several articles describing ASHRAE
Standard 62-1989.
ASHRAE Standard 52-76. Method of
Testing Air-Cleaning Devices Used in
General Ventilation for Removing
Particulate Matter. 1976.
ASHRAE Standard 55-1981. Thermal
Environmental Conditions for Human
Occupancy. 1981.
ASHRAE Standard 62-1989. Ventila-
tion for Acceptable Indoor Air Quality.
1989. '
National Conference of States on Building
Codes and Standards, Inc. The Ventilation
Directory. 505 Huntmar Park Drive, Suite
210, Herndon, VA 22070. 703-481-2020.
Summarizes natural, mechanical, and
exhaust ventilation requirements of the
model codes, ASHRAE standards, and
unique State codes.
TRAINING
American Industrial Hygiene Associa-
tion (AIHA). P.O. Box 8390, 345 White
Pond Drive, Akron, OH 44320. 216-873-
2442. Sponsors indoor air quality courses
in conjunction with meetings for AIHA
members^only, '
American Society of Heating, Refriger-
ating, and Air-Conditioning Engineers
(ASHRAE). 1791 Tullie Circle NE,
Atlanta, GA 30329. 404-636-8400.
Sponsors professional development
seminars on indoor air quality.
NIOSH Division of Training and
Manpower Development and NIOSH-
funded Educational Resource Centers.
4676 Columbia Parkway, Cincinnati, OH
45226. 513-8221. Provide training to
occupational safety and health profession-
als and paraprofessionals.
OSHA Training Institute, 155 Times
Drive, Des Plaines, IL 60018. 708-297-
4913. Provides courses to assist health
and safety professionals in evaluating -
indoor air quality.
Resources 167
-------
Page Intentionally Blank
-------
Indoor Air Quality Forms
I his section of the document is a collec-
tion of the forms that appear or are men-
tioned in the text. Consider making copies
of the forms, blocking out the page infor-
mation at the bottom of the copies, and then
reproducing these copies for use in your
building. Spme or all of them may require
adaptation to meet your specific needs.
Blank formatted sheets are included for
preparing your own HVAC Checklist and
Pollutant and Source Inventory.
The forms appear in the following
sequence:
IAQ Management Checklist (4 pages): for
keeping track of the elements of the IAQ
profile and IAQ management plan
Pollutant Pathway Record For IAQ
Profiles: for identifying areas in which
negative or positive pressures should be
maintained
Zone/Room Record: for recording infor-
mation on a room-by-room basis on the
topics of room use, ventilation, and occu-
pant population.
Ventilation Worksheet: to be used in con-
junction with the Zone/Room Record when
calculating quantities of outdoor air that are
being supplied to individual zones or rooms
IAQ Complaint Form: to be filled out by
the complainant or by a staff person who
receives information from the complainant
Incident Log: for keeping track of each
IAQ complaint or problem and how it is
handled
Occupant Interview (2 pages): for record-
ing the observations of building occupants
in relation to their symptoms and condi-
tions in the building
Occupant Diary: for recording incidents
of symptoms and associated observations
as they occur
Log of Activities and System Operation:
for recording activities and equipment
operating schedules as they occur
HVAC Checklist - Short Form (4 pages):
to be used as a short form for investigating
an IAQ problem, or for periodic inspec-
tions of the HVAC system. Duplicate
pages 2 through 4 for each large air han-
dling unit.
HVAC Checklist - Long Form (14 pages,
followed by one blank formatted sheet):
to be used for detailed inspections of the
HVAC system or as a long form for inves-
tigating an IAQ problem. Duplicate pages
1 through 11 for each large air handling
unit.
Pollutant Pathway Form For
Investigations: to be used in conjunction
with a floor plan of the building.
Pollutant and Source Inventory (6 pages,
followed by one blank formatted sheet):
to be used as a general checklist of poten-
tial indoor and outdoor pollutant sources.
Chemical Inventory: for recording
information about chemicals stored or
used within the building
Hypothesis Form: to be used for
summarizing what has been learned during
the building investigation; a tool to help
the investigator collect his or her thoughts.
Indoor Air Quality Forms 169
-------
Page Intentionally Blank
-------
IAQ Management Checklist
f'age 1 of 4
Building Name:.
Date:.
Address:
Completed by (name/title):,
Use this checklist to make sure that you have included all necessary elements in your IAQ profile and,
IAQ management plan. Sections 4 and 5 discuss the development of the IAQ profile and IAQ management plan.
Item
Date begun
or completed
(as applicable}
Responsible person
(name, telephone)
Location
("NA" if the item is not
applicabl e to this building)
IAQ PROFILE
Collect and Review Existing
Records ' ' - - ' . ' - -:'-/.;...'.."......:
', ' ' ". " " f ,,.".-' : ' ' ,
HVAC design data, operating
instructions, and manuals
HVAC maintenance and calibration
records, testing and balancing reports
Inventory of locations where occu-
pancy, equipment, or building use
has changed
Inventory of complaint locations
Conduct a Walkthrough
Inspection of the Building 1
List of responsible staff and/or
contractors, evidence of training,
and job descriptions
Identification of areas where
positive or negative pressure
should be maintained
Record of locations that need
monitoring or correction
Collect Detailed Information
Inventory of HVAC system
components needing repair,
adjustment, or replacement
Record of control settings and
operating schedules
Indoor Air Quality Forms 171
-------
SAQ Management Checklist
Page 2 of 4.
h\8m
Plan showing ah-flow directions or
pressure differentials in significant
areas
Inventory of signifi'cant pollutant
sources and their legations
MSDSs for supplies and
hazardous substances that are stored
or used in the building!
Zone/Room Record
Date begun
or completed
(as applicable)
Responsible person
(name, telephone)
Location
("IMA" if the item is not
applicable to this building)
IAQ MANAGEMENT PLAN
Select IAQ Manager
Review IAQ Profile
Assign Staff Responsibilities/
Train Staff "
Facilities Operation and Maintenance
ซ confirm that equipment operating
schedules are appropriate
M confirm appropriate pressure
relationships between building
usage areas
compare ventilation quantities to
design, codes, and ASHRAE 62-1989
schedule equipment inspections
per preventive maintenance plan or
recommended maintenance schedule
modify and use HVAC Checklist(s);
update as equipment is added,
removed, or replaced
schedule maintenance activities to
avoid creating IAQ problems
172 Indoor Air Quality Forms
-------
IAQ Management Checklist
Page 3 of 4
Item
review MSDSs for supplies; request
additional information as needed
consider using alarms or other
devices to signal need for HVAC
maintenance (e.g., clogged filters)
Housekeeping
evaluate cleaning schedules and
procedures; modify if necessary
review MSDSs for products in use;
buy different products if necessary
confirm proper use and storage of
materials
review trash disposal procedures;
modify if necessary
Shipping and Receiving
review loading dock procedures
(Note: If air intake is located nearby,
take precautions to prevent intake of
exhaust fumes.)
check pressure relationships around
loading dock
Pest Control
consider adopting 1PM methods
obtain and review MSDSs; review
handling and storage
review pest control schedules and
procedures
review ventilation used during
pesticide application
Date begun
or completed
(as applicable)
Responsible person
(name, telephone)
Location
("MA" if the item is not
applicable to this building)
Indoor Air Quality Forms 173
-------
IAQ Management Checklist
Page 4 of 4
Hem
Occupant Relations
establish health and safety
committee or joint tenant/
management IAQ task force
review procedures for responding
to complaints; modify if necessary
ป review lease provisions; modify
if necessary
Renovation, Redecorating,
Remodeling
* discuss IAQ concerns with
architects, engineers, contractors,
and other professionals
* obtain MSDSs; use materials
and procedures that minimize
IAQ problems
schedule work to minimize
IAQ problems
arrange ventilation to isolate
work areas
use installation procedures
that minimize emissions from
new furnishings
Smoking
eliminate smoking in the building
if smoking areas are designated,
provide adequate ventilation and
maintain under negative pressure
work with occupants to develop
appropriate non-smoking policies,
including implementation
of smoking cessation programs
Date begun
or completed
(as applicable)
Responsible person
(name, telephone)
Location
("NA" if the item is not
applicable to this building)
174 Indoor Air Quality Forms
-------
Pollutant Pathway Record For
IAQ Profiles
This form should be used in combination with a floor plan such as a fire evacuation plan.
Building Name: ; File Number:
Address: '.
Completed by:.
Title:.
. Date:
Sections 2, 4 and 6 discuss pollutant pathways and driving forces.
Building areas that contain contaminant sources {e.g., bathrooms, food preparation areas, smoking lounges, print
rooms, and art rooms) should be maintained under negative pressure relative to surrounding areas. Building areas
that need to be protected from the infiltration of contaminants (e.g,, hallways in multi-family dwellings, computer
rooms, and lobbies) should be maintained under positive pressure relative to the outdoors and relative to surrounding
areas.
List the building areas in which pressure relationships should be controlled. As you inspect the building, put a Y or N
In the "Needs Attention" column to show whether the desired air pressure relationship is present. Mark the floor plan
with arrows, plus signs {+) and minus signs {-) to show the airflow patterns you observe using chemical smoke or a
micromanometer.
Building areas that appear isolated from each other may be connected by airflow passages such as air distribution
zones, utility tunnels or chases, party walls, spaces above suspended ceilings (whether or not those spaces are
serving as air plenums), elevator shafts, and crawlspaces. If you are aware of pathways connecting the room to
identified pollutant sources (e.g., items of equipment, chemical storage areas, bathrooms), it may be helpful to record
them in the "Comments" column, on the floor plan, or both.
Building Area
(zone, room)
Use
Intended Pressure
Positive
(+)
Negative
W
Needs
Attention?
(Y/N)
Comments
Indoor Air Quality Forms 175
-------
Page Intentionally Blank
-------
Zone/Room Record
Building Name:
Address:
File Number:
Completed by:,
Date:.
Title:
This form is to be used differently depending on whether the goal is to prevent or to diagnose IAQ problems. During the development of a profile, this form
should be used to record more general information about the entire building; during an investigation, the form should be used to record more detailed
information about the complaint area and areas surrounding the complaint area or connected to it by pathways.
Use the last three columns when underventilation is suspected. Use the Ventilation Worksheet and Appendix A to estimate outdoor air quantities.
Compare results to the design specifications, applicable building codes, or ventilation guidelines such as ASHRAE 62-1989. (See Appendix A for some outdoor
air quantities required by ASHRAE 62-1989.) Note: For VAV systems, minimum outdoor air under reduced flow conditions must be considered.
PROFILE AND DIAGNOSIS INFORMATION
Building Area
(Zone/Room)
Use**
Source of
Outdoor Air*
Mechanical
Exhaust?
(Write "No"
or estimate
cfm airflow)
Comments
DIAGNOSIS INFORMATION ONLY
Peak Number of
Occupants or
Sq. ft. Floor Area**
Total Air
Supplied
(In cfm}***
Outdoor Air Supplied
per Person or
per 150 Sq. Ft. Area
(in cfm)****
* Sources might include air handling unit (e.g., AHU-4), operable windows, transfer from corridors
** Underline the information in this column if current use or number of occupants is different from design specifications
*** Mark the information with a P if it comes from the mechanical plans or an M if it comes from the actual measurements, such as
recent test and balance reports.
**** ASHRAE 62-1989 gives ventilation guidance per 150 sq. ft.
-------
Page Intentionally Blank
-------
Ventilation Worksheet
Building Name:
Address:
File Number:
Completed by (name):
Date:
This worksheet is designed for use with the Zone/Room Record. Appendix A provides guidance on methods of
estimating the amount of ventilation (outdoor) air being introduced by a particular air handling unit. Appendix B
discusses the ventilation recommendations of ASHRAE Standard 62-1989, which was developed for the purpose of
preventing indoor air quality problems. Formulas are given below for calculating outdoor air quantities using thermal
or CO2 information.
The equation for calculating outdoor air quantities using thermal measurements is:
Outdoor air (in percent) = T
-T
mixed air
return air outdoor air
x100
Where: T = temperature in degrees Fahrenheit
The equation for calculating outdoor quantities using carbon dioxide measurements is:
Outdoor air fin percent}
C -C.
x100
Where: Cs= ppm of carbon dioxide in the supply air (if measured in a room), or
CB= ppm of carbon dioxide in the mixed air {if measured at an air handler)
Cr= ppm of carbon dioxide in the return air
C0= ppm of carbon dioxide in the outdoor air
Use the table below to estimate the ventilation rate in any room or zone. Note; ASHRAE 62-1989 generally states
ventilation (outdoor air) requirements on an occupancy basis; for a few types of spaces, however, requirements are
given on a floor area basis. Therefore, this table provides a process of calculating ventilation (outdoor air) on either
an occupancy or floor area basis.
Zone/Room
Percent of
Outdoor Air
A
Total Air
Supplied to
Zone/Room
(cfm)
B
Peak Occupancy
(number of people)
or
Floor Area
(square feet)
C
>=!-
Total Air
Supplied Per Person
(or per square foot area)
D
E = (AxtOO) x D
Outdoor air
Supplied Per Person
(or per square foot area)
E
Indoor Air Quality Forms 179
-------
Page Intentionally Blank
-------
Indoor Air Quality Complaint Form
This form can be filled out by the building occupant or by a member of the building staff.
Occupant Name: Date:
Department/Location in Building: Phone:.
Completed by: Title: Phone:
This form should be used if your complaint may be related to indoor air quality. Indoor air quality problems include
concerns with temperature control, ventilation, and air pollutants. Your observations can help to resolve the problem
as quickly as possible. Please use the space below to describe the nature of the complaint and any potential causes.
We may need to contact you to discuss your complaint. What is the best time to reach you?
So that we can respond promptly, please return this form to:
IAQ Manager or Contact Person
Room; Building, Mail'Code
OFFICE USE ONLY
File Number: Received By: Date Received:
Indoor Air Quality Forms 181
-------
Page Intentionally Blank
-------
Incident Log
Building Name:
Address:
Dates (from):.
(to):
Completed by (name):.
File
Number
Date
Problem
Location
Investigation Record
(check the forms that were used)
Complaint
Form
Occupant
Interview
1
1*
c>
Logo!
Activities
Zone/Room
Reeord
HVAC
Checklist
Pollutant
Pathway
Source
Inventory
Hypothesis
Form
Outcome/Comments (use more than one line 'if needed)
Log Entry By
{initials}
!
I
09
W
-------
Page Intentionally Blank
-------
Occupant Interview . . page 1 of2
Building Name: , File Number:
Address:
Occupant Name: _^____ Work Location: ;
Completed by: . Title: Date;.
Section 4 discusses collecting and interpreting Information from occupants.
SYMPTOM PATTERNS
What kind of symptoms or discomfort are you experiencing?
Are you aware of other people with similar symptoms or concerns? Yes No
If so, what are their names and locations?
Do you have any health conditions that may make you particularly susceptible to environmental problems?
Q contact lenses Q chronic cardiovascular disease Q undergoing chemotherapy or radiation therapy
Q allergies Q chronic respiratory disease Q immune system suppressed by disease or
other causes
Q chronic neurological problems
TIMING PATTERNS
When did your symptoms start?
When are they generally worst?
Do they go away? if so, when?
Have you noticed any other events (such as weather events, temperature or humidity changes, or activities in the
building) that tend to occur around the same time as your symptoms?
Indoor Air Quality Forms 185
-------
Occupant interview
SPATIAL PATTiRNS
Where are you when you experience symptoms or discomfort?
Page 2 of 2
Where do you spend most of your time in the building?
ADDITIONAL INFORMATION
Do you have any observations about building conditions that might need attention or might help explain your
symptoms (e.g., temperature, humidity, drafts, stagnant air, odors)?
Have you sought medical attention for your symptoms?
Do you have any other comments?
186 Indoor Air Quality Forms
-------
Occupant Diary
Occupant Name:,
Title;
Phone:
Location:,
File Number;
On the form below, please record each occasion when you experience a symptom of ill-health or discomfort that you
think may be linked to an environmental condition In this building.
It Is important that you record the time and date and your location within the building as accurately as possible,
because that will help to identify conditions (e,g., equipment operation) that may be associated with your problem.
Also, please try to describe the severity of your symptoms
-------
-------
Log of Activities and System Operation
Building Name:.
Completed by: _
Address:.
Title:
File Number:.
Phone:
On the form below, please record your observations of the HVAC system operation, maintenance activities, and any
other information that you think might be helpful in identifying the cause of IAQ complaints in this building. Please
report any other observations (e.g., weather, other associated events) that you think may be important as well.
Feel free to attach additional pages or use more than one line for each event.
Equipment and activities of particular interest:
Air Handler(s):
Exhaust Fan(s):
Other Equipmer
Date/Time.
it or Activities:
Day of Week
Equipment Item/Activity
Observations/Comments
Indoor Air Quality Forms 189
-------
Page Intentionally Blank
-------
HVAC Checklist - Short Form
Building Name: Address:.
Page 7 of4
Completed by: - Date: File Number:.
Sections 2, 4 and 6 and Appendix B discuss the relationships between the HVAC system and indoor air quality.
:!;'.;.;'!'.- -",.: ',:-'''./' "'';.'' ,; '' .
Clean and dry? Stored refuse or chemicals?-
Describe items in need of attention
r MAJOR MECHANICAL EQUIPMENT
Preventive maintenance (PM) plan in use?
Control System
Type
System operation
Date of last calibration
Boiler
Rated Btu input Condition
Combustion air: is there at least one square inch free area per 2,000 Btu input?
Fuel or combustion odors .
Cooling Tower
Clean? no leaks or overflow? Slime or algae growth?-
Eliminator performance
Biocide treatment working? (list type of biocide) -
Spill containment plan implemented? Dirt separator working?
Chillers
Refrigerant leaks?
Evidence of condensation problems?
i Waste oil and refrigerant properly stored and disposed of?.
191 Indoor Air Quality Forms
-------
HVAC Checklist - Short Form
Building Name: Address:.
Page 2 of 4
Completed by: Date: File Number:.
AIR HANDLING UNIT
Unit identification. Area served
Outdoor Air Intake, Mixing Plenum, and Dampers
Outdoor air intake location
Nearby contaminant sources? (describe)-
Bird screen in place and unobstructed? _
Design total cfm outdoor air (O.A.) cfm date last tested and balanced.
ซ Minimum % O.A. (damper setting) Minimum cfm O.A. (total cfm x minimum % O.A.) =
100
Current O.A. damper setting (date, time, and HVAC operating mode)
Damper control sequence (describe)
Condition of dampers and controls (note date)
Fans
Control sequence
Condition (note date)
Indicated temperatures supply air mixed air return air outdoor air
Actual temperatures supply air mixed air return air outdoor air
Coils
Heating fluid discharge temperature AT cooling fluid discharge temperature AT.
Controls (describe)
Condition (note date)
Humidifier
Type If biocide is used, note type
* Condition (no overflow, drains trapped, all nozzles working?)
* No slime, visible growth, or mineral deposits?
Indoor Air Quality Forms 192
-------
HVAC Checklist - Short Form
Page 3 of 4
Building Name:,
Completed by: _
.Address:
Date:.
File Number:
DISTRIBUTION SYSTEM
Zone/
Room
System
Type
Supply Air
ducted/
unducted
;-
cf m
Return Afr
ducted/
unducted
cfm
Power Exhaust
cfm
control
serves
(e.g. toilet)
Condition of distribution system and terminal equipment (note locations of problems)
Adequate access for maintenance?
Ducts and coils clean and obstructed?
Air paths unobstructed? supply -
return
transfer -
exhaust
make-up
i Note locations of blocked air paths, diffusers, or grilles
i Any unintentional openings into plenums?
i Controls operating properly?
i Air volume correct? _
Drain pans clean? Any visible growth or odors?
Filters
Location
Type/Rating
Size
Date Last Changed
Condition (give date)
193 Indoor Air Quality Forms
-------
HVAC Checklist - Short Form
Page 4 of 4
Building Name:.
Completed by; _
Address:
. Date:.
Ale Number:
OCCUPIED SPACE
Thetmostat
i Zone/
1 Room
i
1
t
L
i
L.
!
L_
tVDffS
Thermostat
Location
What Does
Thermostat
Control?
(e.g., radiator,
AHU-3)
Setpoints
Summer
Winter
Measured
Temperature
Day/
Time
2ona{
! Room
i
Humfdistat/
Dehumidistat
Location
What Does It
Control?
Setpoints
|%RH)
Measured
Temperature
Day/
Time
Potential problems {note location)
t Thermal comfort or air circulation problems (drafts, obstructed airflow, stagnant air, overcrowding, poor
thermostat location)
Malfunctioning equipment
Major sources of odors or contaminants {e,g., poor sanitation, incompatible uses of space)
Indoor Air Quality Forms 194
-------
HVAC Checklist - Long Form
Page 1 of 14
Building:.
File Number:
Completed by:.
Title:
Date Checked:
Appendix B discusses HVAC system components in relation to indoor air quality.
Component
OK
Needs
Attention
Not
Applicable
Comments
'' Outside Air Intake ' ','.'--. . : ' :/ :/ ' "'
I nrstHnn
Open during occupied hours?
Unobstructed?
Standing water, bird droppings
in vicinity?
Odors from outdoors?
(describe)
Carryover of exhaust heat?
Cooling tower within 25 feet?
Exhaust outlet within 25 feet?
Trash compactor within 25 feet?
Near parking facility, busy road,
loading dock?
Bird Screen ^-"^ .":'' .'':': \-::-'-":", :.'" .'-".':' ::.:';..V'v- :;:;'"',^; : '.;'' ''.-^.-- .- ' ' ,-. ' ''"
' -" ."''- -.' '.-'}'.'' '.-.:.'. <.;'v--V';.'- --':-''-'.-? "^'l-. ^'':.: .:'...'.- ."- '--,. -' ^----;'- :*' '" " :' . -.,-.",.- - - '.:.-.-.
Unobstructed?
General condition?
Size of mesh? (1/2" minimum)
' ,-.- * -
Outside Air Dampers
Operation acceptable?
Seal when closed?
Indoor Air Quality Forms 195
-------
HVAC Checklist - Long Form
Page 2 of 14
Building:.
Completed by:.
File Number:
Title:.
Date Checked:.
Component
Actuators operational?
Outdoor Air (O.A.) Quantity
(Chock *g*lnst appltcmbte coda*
endASHRAE 62-1989.) ^
Minimum % Q A
Mftn*Himri *& O A
Note day, time, HVAC operating
mode under 'Comments'
Is minimum O.A. a separate damper?
For VAV systems: is O.A. increased
as total system air-flow is reduced?
;;" ,'",:: ; "" , " " ":;'||ii ; ' ' " i
Mixing Pienum
Clean?
Floor drain trapped?
Alrtightness
of outside air dampers
of return air dampers
of exhaust air dampers
AH damper motors connected?
All damper motors operational?
Air mixers or opposed blades?
OK
Needs
Attention
"' "lil ' ' "" '
Not
Applicable
Comments
. ...
'.'"";;. "'. ;;";;;,; ' ; ; ';" ".,,.;';
196 Indoor Air Quality Forms
-------
HVAC Checklist - Long Form
Page 3 of 14
Building:.
Completed by:.
File Number:
Title:
Date Checked:
Component
Mixed air temperature control
ssttincj ^F
Frfi^fi ?t?rt setting ฐF
Is mixing plenum under negative
pressure? Note: If it is under
positive pressure, outdoor air
may not be entering.
OK
Needs
Attention
Not
Applicable
Comments
fat*** ,'-." -'---'-.'*---, - " .. K ;.;;; ''.TT: ,.;' '' :; ;. --. --'r. = -
.- . . ' ---':". '.::.' :,:-. :- ..-.-.. -.- - " - .'": -
Typซ
Complete coverage?
(i.e., no bypassing)
Correct pressure drop? (Compare to
manufacturer's recommendations.)
Contaminants visible?
Odor noticeable?
Spray Humidifiers or ;..' ' ; ;._' "' ''. .. : _''-. '.;."; / ' .' ;^- _ ' -.-.,; ' '; .. - . -
Air Washers " , : ."; /: .';':'. ~*.'-\ '- . ^.. -;'.:.' ,^. \ - ' .''^^'/ : " '- ' . . ;
Humidifier type
AH nozzles working?
Complete coil coverage?
Pans clean, no overflow?
Drains trapped?
Biocide treatment working?
Nntft: Is MSDS on file?
Spill contaminant system in place?
Indoor Air Quality Forms 197
-------
HVAC Checklist - Long Form
Page 4 of 14
Building;.
Completed by:.
File Number:
Title:.
Date Checked:.
Component
Face and Bypass Dampers
Damper operation correct?
Damper motors operational?
! Cooling Coil
| ,!! ,. . ' ' ป ' ' i , v MI t ' :
Inspection access?
Clean?
Supply water temp, ?F
Water carryover?
Any indication of condensation
problems?
Condansata Drip Pans
Accessible to inspect and clean?
Clean, no residue?
No standing water, no leaks?
Noticeable odor?
Visible growth (e.g., slime)?
Drains and traps clear, working?
Trapped to air gap?
Water overflow?
OK
Needs
Attention
Not
Applicable
,i; ,,,,, |ll ,, ,
Comments
198 Indoor Air Quality Forms
-------
HVAC Checklist - Long Form
Page 5 of 14
Building:.
Completed by:.
File Number;
Title:.
Date Checked:
Component
OK
Needs
Attention
Not
Applicable
Comments
Mist Eliminators
Clean, straight, no carryover?
'-'-,.;- "~ ' ' S
Supply Fan Chambers ' _ '.
'- 'V ,-"'.'..," - , , 1
Clean?
No trash or storage?
Floor drain traps are wet or sealed?
No air leaks?
Doors close tightly?
Supply Fans
Location
Fan blades clean?
Belt guards Installed?
Proper belt tension?
Excess vibration?
Corrosion problems?
Controls operational, calibrated?
Indoor Air Quality Forms 199
-------
HVAC Checklist - Long Form
Page 6 of 14
Building:.
Completed by:.
File Number:
Title:.
Date Checked:.
Component
Control sequence conforms
to design/specifications?
(describe changes)
No pneumatic leaks?
I Hซtf ng Coil
Inspection access?
Clean?
Control sequence conforms to
design/specifications?
(describe changes)
Discharge thermostat?
(sir tsmp settino ^F)
Rซhซ*t Coils
Clean?
Obstructed?
Operational?
Stoซm Humidifier
Hปnr>Mifinrtypซ
Treated boiler water?
Standing water?
OK
I
Needs
Attention
Not
Applicable
Comments
' . i if i M * i r i
( .' . . ; ' ''<" :n| IP ,; i.; .. ': .'IM' y ., " '"''' '. '!
' "' '' ' ; ' ' .,'", ซ
ZOO Indoor Air Quality Forms
-------
HVAC Checklist - Long Form
Page 7 of 14
Building:.
Completed by:,
File Number:.
Title:
Date Checked:.
Component
Visible growth?
Mineral deposits?
Control setpoint >^F
High limit setpoint ฎF
Duct liner within 12 feet? (If so,
check for dirt, mold growth.)
OK
Needs
Attention
Not
Applicable
Comments
Supply Ductwork . . .
Clean?
Sealed, no leaks, tight connections?
Fire dampers open?
Access doors closed?
Lined ducts?
Flex duct connected, no tears?
Light troffer supply?
Balanced within 3-5 years?
Balanced after recent renovations?
Short circuiting or other air
distribution problems? Note
location(s)
Pressurized Ceiling ,
Supply Plenum
No unintentional openings?
All ceiling tiles in place?
Indoor Air Quality Forms 201
-------
HVAC Checklist - Long Form
Page 8 of 14
Building;.
File Number:.
Completed by;.
Title:
Date Checked:.
Component
Barrier paper correctly placed and
in good condition?
Proper layout for air distribution?
Supply diffusers open?
Supply diffusers balanced?
Balancing capability?
Noticeable flow of air?
Short circuiting or other air
distribution problems? Note
tocationM ^'Comments"
- Twrmfiujl Equipment (supply)
Housing interiors clean and
unobstructed?
Controls working?
Delivering rated volume?
Balanced within 3-5 years?
Pillars in place?
Condensata pans clean, drain
freely?
OK
Needs
Attention
Not
Applicable
Comments
i
VAVBox
"
i.*"'"' '" .~;'" "' - - i*"*: ' :'' ""' 'ป'" ':'' ''# ' ^ ^^ ^'i^^>9i"^9i^^lflfft'
-------
HVAC Checklist - Long Form
Page 9 of 14
Building:.
File Number:
Completed by:.
Title:.
Date Checked:
Component
Supply setpoint ฐF (summer)
ฐF (winter)
OK
Needs
Attention
Not
Applicable
Comments
Thermostats , . ,
Typfi
Properly located?
Working?
Setpoiflts ฐF (fiiimrnpr)
ฐF {wfrrt-fir}
SpafifitftrnperatiiM* ฐF
Humidity Sensor
Humidtetnt sotpoints % PH
DBhirmWisl'ataetpointR % RH
Actual RH %
Room Partitions
Gap allowing airflow at top?
Gap allowing airflow at bottom?
Supply and return each room?
Indoor Air Quality Forms 203
-------
HVAC Checklist - Long Form
Page 10 of 14
Building:,
Completed by:.
File Number:
Title:
Date Checked:.
Component
OK
Needs
Attention
Not
Applicable
Comments
[Stairwell* ' ' '
Doors close and latch?
No openings allowing
uncontrolled airflow?
Clean, dry?
No noticeable odors?
pRteturn Air Plenum
Tiles In place?
No unintentional openings?
Return grilles?
Balancing capability?
Noticeable flow of air?
Transfer grilles?
Fire dampers open?
Ductod RMurn*
Balanced within 3-5 years?
Unobstructed grilles?
Unobstructed return air path?
jftatum Fan Chambers '' * ' ' ' ''":"" .- "
' ':;N ' . , ' . :... .!..': , , ;.. , ,.' . . . -/.-:. : ", , ,. , . . . '. ;
Ctaan and no trash or storage?
No standing water?
Floor drain traps are wet or sealed?
204 Indoor Air Quality Forms
-------
HVAC Checklist - Long Form
Page 11 Of 14
Building:.
Completed by:.
File Number:.
Title:
Date Checked:
Component ,
No air leaks?
Doors close tightly, kept closed?
OK
Needs
Attention
Not
Applicable
Comments
Return Fans ' . ',..'. ,. I
Location
Fan blades clean?
Belt guards installed?
Proper belt tension?
Excess vibration?
Corrosion problems?
Controls working, calibrated?
Control sequence conforms to
design/specifications?
(describe changes)
Exhaust Fans
Central?
Distrihpted (loo*>t'on?5)
Operational?
Controls operational?
Toilet exhaust only?
Gravity relief?
Indoor Air Quality Forms 205
-------
HVAC Checklist - Long Form
Page 12 of 14
Building:.
Completed by:.
Title:
File Number:
Date Checked:.
Component
Totfll powsrsd exhaust , , Rfrn
Make-up air sufficient?
ST.! :~r i WJ.MUW**. .( a
Toilet Exhausts
i' i.
Fans working occupied hours?
Registers open, clear?
Make-up air path adequate?
Volume according to code?
Floor drain traps wet or scalable?
Bathrooms run slightly negative
relative to building?
f f ,!,-.-.,
Smoking Lounge Exhaust
Room runs negative relative to
building?
:WntRoomiExhauซt "". . "**"
Room runs negative relative
to building?
! ปsr !ป i , I- =ป .>,.. j, , , ,, .sa^swf"***1' ilniniil JซH ซ
[Garage Ventilation
Operates according to codes?
Fans, controls, dampers all operate?
OK
MMMfW
TT 7*m it' ffi^
.-
ซy^w
Needs
Attention
i .* ,ป
~ฐ' i
,
|| I" *MMH^1
1I^rflHซltlllH| ttmfrk.
Not
Applicable
mmmiimfer v. ,(,i
'fSt~ 'V *iiซ .
Comments
; vimiMMW ' i i; , . 1 i^-tn^ii
*
Vi^^wijwsri) , [ปjsป^ I ] ^' ฐ i i* ,
SJ.W^V*?**'''"/'.''!^:' .' i-Jn&l&''if*i&:-* -' ''''. f >-'. .'''> ; '. -.;..... ' - s.
206 Indoor Air Quality Forms
-------
HVAC Checklist - Long Form
Page 13 of 14
Building:.
File Numbed.
Completed by;.
Title:
Date Checked:.
Component :
Garage slightly negative relative
to building?
Doors to building close tightly?
Vestibule entrance to building
from garage?
OK
Needs
Attention
Not
Applicable
Comments
Mechanical Rooms . ' j
General condition?
Controls operational?
Pneumatic controls:
compressor operational?
air dryer operational?
Electric controls? Operational?
EMS (Energy Management System)
or DDC (Direct Digital Control):
operator on site?
controlled off-site?
are fans cycled "off" while
building is occupied?
is chiller reset to shed load?
Preventive Maintenance
,..;---"" ' ~ 3
Spare parts inventoried?
Spare air filters?
Control drawing posted?
Indoor Air Quality Forms 207
-------
HVAC Checklist - Long Form
Page 14 of 14
Building;.
Completed by;.
File Number:
Title:.
Date Checked:.
Component
PM {Preventive Maintenance)
schedule available?
PM followed?
B0tt*t*^^,::^.^ '":
Flues, breeching tight?
Purge cycle working?
Door gaskets tight?
Fuel system tight, no leaks?
Combustion air: at least 1 square
I Inch free area per 2000 Btu input?
. Cooling 'Tower
Sump clean?
No leaks, no overflow?
Eliminators working, no carryover?
No slime or algae?
Biocide treatment working?
Dirt separator working?
Chiller*
No refrigerant leaks?
Purge cycle normal?
Waste oil, refrigerant properly
disposed of and spare refrigerant
properly stored?
Condensation problems?
OK
..
Needs
Attention
Zy^r^f, _.,
i .a'^i.&wr,' ^'
Not
Applicable
"a---
t.
Comments
..:.-.. - .. -;: . . J
ฃ * "" j r . :,i!,:,j:'i M, n'.-.inL," - :.,.' -i ,*,_'/- ''-;- ,','! - . ?, ' . * j
^ 1 ~ฃt '. ป ป J I1! %lV i ', -''S -ซ.,'--. -.-. - ;,/ ' * i-> :;:* - f M
. . ' ',.':' ','- ' .". ' " &" ;. , . ~ . . , ' " '1
208 Indoor Air Quality Forms
-------
HVAC Checklist - Long Form
Page__ of
Building:.
Completed by:.
File Number:.
Title:.
Date Checked:.
Component
OK
Needs
Attention
Not
Applicable
Comments
Indoor Air Quality Forms 2O9
-------
-------
Pollutant Pathway Form For Investigations
Building Name:
Address:
File Number:
Completed by:
This form should be used in combination with a floor plan such as a fire evacuation plan.
Building areas that appear isolated from each other may be connected by airflow passages such as air distribution zones,
utility tunnels or chases, party walls, spaces above suspended ceilings (whether or not those spaces are serving as air
plenums), elevator shafts, and crawl spaces.
Describe the complaint area in the space below and mark it on your floor plan. Then list rooms or zones connected to the
complaint area by airflow pathways. Use the form to record the direction of air flow between the complaint area and the
connected rooms/zones, including the date and time. (Airflow patterns generally change over time). Mark the floor plan
with arrows or plus (+) and minus (-) signs to map out the airflow patterns you observe, using chemical smoke or a
micromanometer. The "Comments" column can be used to note pollutant sources that merit further attention.
Rooms or zones included in the complaint area:
Sections 2,4 and 6 discuss pollutant pathways and driving forces.
Rooms or Zones
Connected to the
Complaint Area
By Pathways
Use
Pressure Relative to
Complaint Area
+/-
date/time
Comments (e.g., potential pollutant sources)
Indoor Air Quality Forms 211
-------
Page Intentionally Blank
-------
Pollutant and Source Inventory
Page 1 of 6
Building Name:.
Completed by: _
Address:
Date:.
. File Number:.
Using the list of potential source categories below, record any indications of contamination or suspected pollutants
that may require further investigation or treatment. Sources of contamination may be constant or intermittent or may
be linked to single, unrepeated events. For intermittent sources, try to indicate the time of peak activity or contami-
nant production, including correlations with weather (e.g., wind direction).
Sections 2, 4 and 6 discuss pollutant sources. Appendix A provides guidance on common measurements.
Source Category
Checked
Needs
Attention
Location
Comments
SOURCES OUTSIDE BUILDING
Contaminated Outdoor Air
Pollen, dust
Industrial contaminants
General vehicular contaminants
Emissions from Nearby Sources
Vehicle exhaust (parking areas,
loading docks, roads)
Dumpsters
Re-entrained exhaust
Debris near outside air intake
Soil Gas , , ' ': '
Radon
Leaking underground tanks
Sewage smells
Pesticides
Indoor Air Quality Forms 213
-------
Pollutant and Source Inventory
Page 2 of 6
Building Name;.
Completed by: _
. Address:.
Date:.
. File Number:.
Using the IFst of potential source categories below, record any indications of contamination or suspected pollutants
that may require further investigation or treatment. Sources of contamination may be constant or intermittent or may
bo linked to single, unrepeated events. For intermittent sources, try to indicate the time of peak activity or contami-
nant production, including correlations with weather {e.g., wind direction). '
Source Category
!'16lo{ซtura"dr'Stim3lng Water
Rooftop
Crawlspace
I HVAC System Equipment
Combustion gases
Dust, dirt, or microbial growth
in ducts
Microbial growth in drip pans,
chillers, humidifiers
Leaks of treated boiler water
^ Won HVAC System Equipment
Office Equipment
Supplies for Equipment
Laboratory Equipment
Checked
--''""""-
^ \X-
,t ,,
'"'
Needs
Attention
.,
j-r!r
JH 1
Location
-':i .-Jป'x T^,,:,,i'
4fcrtป# A*tJ*S #, **= ^
Comments
, ,* . . ,. , , -y
??*taefiffr.*.-ป-. -.v .-..-.. . ...>-, -/.:,;>, '<
Indoor Air Quality Forms 214
-------
Pollutant and Source Inventory
Page 3 of 6
Building Name:.
Completed by: _
. Address:.
Date:.
. File Number:.
Using the tist of potential source categories below, record any indications of contamination or suspected pollutants
that may require further Investigation or treatment. Sources of contamination may be constant or intermittent or may
be linked to single, unrepeated events. For,intermittent sources, try to indicate the time of peak activity or contami-
nant production, including correlations with weather (e.g., wind direction), ,
Source Category
Checked
Needs
Attention
Location
Coinitients
HUMAN ACTIVITIES , V , . -' :
ซ" . * ' - ** * . : * ! ' ~ r ~ * "*
Personal Activities *''.'.. . " . . . ซ -,. .-<.
Smoking
Cosmetics (odors)
Housekeeping Activities ..'.;.. , ",
Cleaning materials
Cleaning procedures (e.g., dust
from sweeping, vacuuming)
Stored supplies
Stored refuse
Maintenance Activities ^ ^ ' ' , .. : .
Use of materials with volatile
compounds (e.g., paint, caulk,
adhesives)
Stored supplies with volatile
compounds
Use of pesticides
Indoor Air Quality Forms 215
-------
Pollutant and Source Inventory
Page 4 of 6
Building Name:,
Completed by: _
. Address:.
Date:
File Number:
Using the list of potential source categories below, record any indications of contamination or suspected pollutants
that may require further investigation or treatment. Sources of contamination may be constant or intermittent or may
ba linked to single, unrepeated events. For intermittent sources, try to indicate the time of peak activity or contami-
nant production, including correlations with weather (e.g., wind direction).
Source Category
Checked
'
BUILDING COMPONENTS FURNISHINGS
ฃ ' " ' ' r, , * ,...j>.^ ,,.. t
Needs
Attention
Location
Comments
, . ' -.. v'l'\' . . , , "'!
f" , ' : >f '.t " ' * ,. mi% "' i, " H ป "Hf**" ซ,- yปi j is-aft ' ^^ II ป II #" i-** "fsStfn (*. ซJ K V- t I I , t, m, ป i ป ",(,'.,
! Locations Associated with Dust or Fibers
Dust-catching area
(e.g., open shelving)
Deteriorated furnishings
Asbestos-containing materials
i " _-,-, ,,, ,
Unsanitary Conditions/Water Damage
MIcrobial growth in or on soiled
or water-damaged furnishings
;;" ";_ ";'" ''';''' ;;;V ''y ' '! ;"*'!''''? r!" "''"' '""' """"""'
Indoor Air Quality Forms 216
-------
Pollutant and Source Inventory
Page 5 of6
Building Name:.
Completed by: _
Address:
Date:.
File Number:,
Using the list of potential source categories below, record any indications of contamination or suspected pollutants
that may require further investigation or treatment. Sources of contamination may be constant or intermittent or may
be linked to single, unrepeated events. For intermittent sources, try to indicate the time of peak activity or contami-
nant production, including correlations with weather (e.g., wind direction).
Source Category
Checked
Needs
Attention
Location
Comments .
ฐ*
Chemicals Released From Building Components or Furnishings -
Volatile compounds
1
.OTHER SOURCES i
i
Accidental Events , . :
Spills (e,g,, water, chemicals,
beverages)
Water leaks or flooding
Fire damage
e-
.
Indoor Air Quality Forms 217
-------
Pollutant and Source Inventory
Page 6 of 6
Building Name;,
Completed by: _
.Address:.
Date:.
File Number:
Using the list of potential source categories below, record any indications of contamination or suspected pollutants
that may require further investigation or treatment. Sources of contamination may be constant or intermittent or may
bo linked to single, unrepeated events. For intermittent sources, try to indicate the time of peak activity or contami-
nant production, including correlations with weather (e.g., wind direction).
Soured Category
Checked
Needs
Attention
Location
Comments
. _ _ ^ ^ ,,>', ( ,'', i i
[s$MHrfซIUtซ/M!xซI Use Areas ' "^ "";' *-*,* ,....,,... . ...
Smoking lounges
Food preparation areas
Underground or attached
parking garages
Laboratories
Print shops, art rooms
Exercise rooms
Beauty salons
1 Rซdซcor*ting/Repair/Remode!irtg " ,_...,.,
Pat "I*, .Jfcp1 in m i* !?i? ' A JL jbii Mi w.*t i n - '
-------
Pollutant and Source Inventory
Page_of ;
Building Name:,
Completed by: _
Address:.
Date:
. File Number:,
Using the list of potential source categories below, record any indications of contamination or suspected pollutants
that may require further investigation or treatment. Sources of contamination may be constant or intermittent or may
be linked to single, unrepeated events. For intermittent sources, try to indicate the time of peak activity or contami-
nant production, including correlations with weather (e.g., wind direction).
Sections 2, 4 and 6 discuss pollutant sources. Appendix A provides guidance on common measurements.
Source Category
Checked
Needs
Attention
Location
Comments
Indoor Air Quality Forms 219
-------
Page Intentionally Blank
-------
Chemical Inventory
Building Name:.
Address;
File Number:
Completed by:.
Phone:
The inventory should include chemicals stored or used in the building for cleaning, maintenance, operations, and pest
control. If you have an MSDS (Material Safety Data Sheet) for the chemical, put a check mark in the right-hand column.
If not, the chemical supplier to provide the MSDS, if one is available.
Sections 2,4 and 6 discuss pollutant sources. Section 4 discusses MSDSs.
Date
Chemical/Brand Name
Use
Storage Location(s)
MSDS on file?
Indoor Air Quality Forms 221
-------
Page Intentionally Blank
-------
Hypothesis Form
Page 1 of2
Building Name: File Number:
Address:
Completed by:.
Complaint Area (may be revised as the investigation progresses):
Complaints (e,g., summarize patterns of timing, location, number of people affected):
HVAC: Does the ventilation system appear to provide adequate outdoor air, efficiently distributed to meet occupant
needs in the complaint area? If not, what problems do you see?
Is there any apparent pattern connecting the location and timing of complaints with the HVAC system layout, condition
or operating schedule?
Pathways: What pathways and driving forces connect the complaint area to locations of potential sources?
Are the flows opposite to those intended in the design?
Sources: What potential sources have been identified in the complaint area or in locations associated with the complaint
area (connected by pathways)?
Is the pattern of complaints consistent with any of these sources?,
Indoor Air Quality Forms 223
-------
Hypothesis Form
Page 2 of 2
Hypothesis: Using the information you have gathered, what is your best explanation for the problem?
Hypothesis testing: How can this hypothesis be tested?
If measurements have been taken, are the measurement results consistent with this hypothesis?
Results of Hypothesis Testing:
Additional Information Needed:
224 Indoor Air Quality Forms
-------
Index
Adr distribution, see also HVAC system, Ventilation 7-8,24-27,35,38,57-71,82-84, 88,92-93,111-115,121-135,146,
177,193,201-206
Air handling units, see also HVAC system 124-130,177,192,199
Air pressure, see HVAC system, Pressure relationships, and Ventilation
Airflow, see also Pressure relationships and Ventilation 24,26,64,71,99,104,114,121-122,125
Asbestos 63,147-150,164-165
ASHEAE, see also Standards, guidelines, and advisories 121,167
Guideline 1-1989 139
Standard 52-1976 126,138
Standard 55-1981 57,66,129,137 ,
Standard 62-1989 8,14,28, 34-35,41,60,64-66,82-87,115,126,136-137
Bioaerosols, see Biological contaminants
Biocides 5,73,91,94-95, 132
Biological contaminants 5, 24, 35-36,40,48,56,63,76,82,86,91-95,102-105,117-118,125,127,129,131-132,135,
138,141-146,165
measuring 105,117
Boilers, see also HVAC system 87-88,113,124,135
Building-related illness (BRI) 11,86,101,105
Carbon dioxide (CO2) 36,49,57-58,60-61,74-76,87,110-115
Carbon monoxide (CO) 10,37,56,58,75-77,100,113,118, 135
Chemical Inventory 23,26,72-73,169,221
Chemical smoke 22,60-61,68,75,77,110-112
Chillers, see also HVAC system 124,135,137
Cleaning materials 32,36,73,97
Combustion gases 29,56,75,86,89,100,113
Complaint area 49,53-54,65,68-69,76
Complaints 10-11,27,32,46,103
Indoor Air Quality Complaint Form 15,32,169,181
responding to 14-17
Control systems, see also HVAC system S, 19-21,23,26,31,34-36,47,57,60,64-65,76, 82; 92, .
122-126, 128-130,134-135,145
Cooling coils, see also HVAC system 35,67, 97,123-124,126,128
Cooling towers, see also HVAC system 24,28,35, 89,101, 135
Dampers, see also HVAC system 24,60,65,87,125,130,133
fire dampers 25,130
mixing boxes (mixed air plenums) 124-126
outdoor air dampers 59-60,125
Diffusers, see also HVAC system 58-61,67,82-83,87-88,113-114,133
Index 225
-------
Ductwork, see also HVAC system 36, 61, 73, 91, 102, 127, 131-132
cleaning 36, 61, 73, 91, 102, 127, 131-132
leakage 67, 87, 130
plenum 24-25, 61, 67, 87, 92, 123, 125, 130, 131, 133
return 65, 87, 99, 130, 133
supply 61, 65, 99-100, 114, 123
Dust 23, 25, 32, 67, 72-73, 118, 126, 131, 138
Elevators 68- 69, 93
Environmental stressors 1 1 , 55-56, 77-78, 85
Environmental tobacco smoke (ETS) 6, 9-10, 24-25, 32, 35, 40-41, 66, 73, 81-82, 90, 1 16, 1 18. 166
EPA, see Standards, guidelines, and advisories
Ergonomic stressors 55-56, 78, 85
Exhaust air, see HVAC system and Ventilation 8-9, 58, 65, 82, 89, 114, 124, 133, 154
Exhaust fumes 53, 72, 1 00
Fans, see also HVAC system 22, 48, 87, 89, 124, 130, 133, 145
Filters, see also HVAC system 2, 36, 48, 60-61, 84, 91-92, 123, 126-128, 130, 138
Fire codes 27, 58, 83
Formaldehyde 56, 82, 85, 1 16- 1 17
Furnishings 34, 40, 72-73, 78, 86, 93, 96, 99, 102, 122, 133, 145
Health and safety 52, 56, 63, 76, 101, 105, 117, 147
committee 16-17, 40, 76
considerations for investigators 52, 56, 63, 76, 101, 105
Humidification, see also HVAC system 35, 56, 60, 90, 101, 129, 141
Humidity, see Moisture 24, 49, 56, 67, 60, 82, 89, 94, 1 10-1 1 1, 123, 125, 129
HVAC Checklist - Long Form 26, 58, 61, 169, 175, 195-209
HVAC Checklist - Short Form 26, 58, 61- 62, 169, 191-194
HVAC system 5, 6-9, 57-59, 62, 79, 86, 89, 1 1 1, 121, 123, 154
components 57, 64, 83, 87, 94, 123-137
design types 7-8, 57-59, 61- 62, 64- 65, 121-123
maintenance 22-23, 62, 67, 91, 122
operation 6, 25, 52, 55-59, 62, 89, 122, 189
zones 47, 58, 76, 82, 1 12, 121-122, 169
Hypothesis
developing and testing hypotheses 46, 57, 67, 71, 74-75, 78-79, 223
Hypothesis Form 57, 67, 71, 74, 78-79, 169, 223-224
cident Log 16, 49, 169, 183
IAQ Management Checklist 42, 169, 171-174
IAQ management plan flowchart 32
IAQ manager 32-33
IAQ profile flowchart 20
IAQ task force 13,17,40
Indoor Air Quality Complaint Form 15, 169, 18 1
Infiltration, see Airflow and Pressure relationships
Integrated Pest Management (IPM), see Pest control
226 Index
-------
Intermittent problems 10,55,59,72,74,77
Interview, see Occupant Interview
Investigation
collecting additional information 20,25-29,49-74
flowchart 45
forming hypotheses, see Hypothesis, developing and testing
outside assistance 20, 40, 45, 47, 63,105-108, 117
reviewing existing records 20-22, 50, 58
sampling 74-77,109-119
walkthrough 45,47-49
Legionnaire's disease 11,56,101
Lighting 11,24-25,55,77-78, 85- 86
Loading docks 23,25, 37, 89,100
Local exhaust, see also HVAC system and Pressure relationships 9,22,40,65, 82-83,90, 92,94, 97,99-100,102,137
Log of Activities and System Operations 52,53,58,77,139,169,189
IVIaintenance 24, 31, 34, 36, 67, 97
preventive 23,36
records 22-23
schedule 23,34-35,139
Manometer 36,58,68-69,110
Material Safety Data Sheets (MSDS) 20, 28,32, 35,38-40,73
Measurement
comparing to standards and guidelines 75- 76, 87
devices 48,58,75,109-119
developing measurement strategy 48,74-77
Microbiological contaminants, see Biological contaminants
Mildew, see Biological contaminants
Mitigation
evaluating approaches 102-103
judging success 75,103-104
managing projects 103
persistent problems 104
using air cleaning 81, 84-85, 89,92
using exposure control 81,85,93,96-99
using source control 81-82,89-101
using ventilation 41,81-84, 87-100
Mixing boxes, see also HVAC system 61,124-126
Moisture 23-24, 95,128,131,141-146
humidity 24,60,120,122,137-138,141-146
water damage 24,73,94,128,131-132,141-142
Mold, see Biological contaminants
Multiple chemical sensitivity (MCS) 12
IMlOSH, see also Standards, guidelines, and advisories 41, 63, 75, 81, 84, 111, 116,119,147-149,154,157.
164-165,167
Noise 11,55,77-78,85-86,127
Index 227
-------
Occupants 5,10-11
complaints 10,46,48,50,72,131
density 24,66,73,78,87,122,136
Occupant Diary 52,77,169,187
Occupant Interview 50-52,169,185
occupant relations (IAQ management plan) 40
Odors 8,24-25,49,65
Outdoor air intake 5,10,25,56,58,65,89,99-100,121,124-125
Outdoor sources of contaminants 5,25,56- 57,72-74,86,89,102,113,127
"^eppermint oil 69
Pest control 23,32,37-38,43,73, 84, 89
Integrated Pest Management (EPM) 38
pesticides 23,32,37-38,76,85,96,116
Pollutant pathways and driving forces 5,9-10,50,54,69-70,79,82,84,89,97,100,115,152
Pollutant and Source Inventory 25-26,28,72-74,169,213
Pollutant Pathway Form for Investigations 67,69,169,211
Pollutant Pathway Record IAQ Profile 26-27,33,169,175
Pressure relationships, seealso Airflow and HVAC system 8-9,27,35,37,45,66-68,71,82-83,89,93,98,100-111,127,
133-134,144
negative/positive 8,26-27,37,70,82-83,89,98,100,110-111,127,132,141,154-155
Preventive Maintenance, see also Maintenance 36,132
Psychrometer 111,143
Psyehosocial stressors 11,55- 56,77-78
Purchasing 32,35,37,41,81
Radon 5,89,151-152,167
Recirculation, see Ventilation
Redecorating/Renovation/Remodeling 21,32,34,40,55,66,73,86,99
Return air, see HVAC system and Ventilation
Roofing 23,85,89,99
^Sampling and analysis, see Measurement
Sick building syndrome (SBS) 11,155
Smoking, see Environmental tobacco smoke
Sources, see also Pollutant and Source Inventory and specific sources (by name) 5,6, 8-9,26,28, 35,48,72-74,76,
81-82,90
Special use areas 25,65,73, 86,90,93,96,98,133-134
Standards, guidelines, and advisories, see also ASHRAE, NIOSH 43,75-76,167
Storage practices 23,25,37,73,97
Supply air, see HVAC system and Ventilation
Surface contamination, see also Biological contaminants 6,37,76,86,91,94
I erminal devices, see HVAC system
Testing and balancing 21,43,48,58,87,92,94,98-99,103,123
Thermal comfort 7,24,56-57,87,89,110-111,121,133-134,137,167
Thermal mass balance 114-115
Thermostats, seealso HVAC system 24,59-60,64-65,67,111,122,134-135,145
228 Index
-------
Tools
for IAQ investigations 45,48-50,58,68,72,77,109-119
for IAQ profiles 20,22
Total volatile organic compounds (TVOCs) 115-116
Tracer gas 58,69,77,112-113,126
Trainingm 31,33,41,117; 139,167
Trash disposal 23,37,89
Unit ventilators, see HVAC system
Unsanitary conditions 24-25, 38,65,67,72,94,117
V entilation, see also Airflow, ASHRAE 62-1989, HVAC system, Pressure relationships 7, 8-10,24, 65, 83-84,110,113,
122,126,130-131,133,136,139,144,167
air distribution 61,69,86-87,95,104
outdoor air 24,65, 82-83, 86-87,91-92,96,99-100,102,113-115,121,122-125,135,145
measuring 87-88
recirculation 82,92
total air 65,82-83,95,99,104,113-114
underventilation 24,56-57,60,66-67,82-83,87-88,112-113
Ventilation Worksheet 169,179
Vibration 11,77-78,85-86
Volatile organic compounds (VOCs) 6,82,96,99,102,115-116
Walkthrough
profile 20-25
investigation 45,47-49
Water chillers, see also HVAC system 137
Water, see Moisture
Zone/Room Record 28-29,61- 62,169,177
*U.S. G.P.O.:1993-752-419:419 Index 229
-------
Page Intentionally Blank
-------
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D publicly owned EH privately owned
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I found this publication:
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NO POSTAGE
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MAILED IN THE
UNITED STATES
BUSINESS REPLY MAIL
FIRST CLASS MAIL PERMIT NO. 11663 WASHINGTON, DC
POSTAGE WILL BE PAID BY ENVHONMENTAL PROTECTION AGENCY
INDOOR AIR DIVISION (ANR-445W)
U.S. ENVIRONMENTAL PROTECTION AGENCY
401 M ST SW
WASHINGTON DC 20277-1663
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NO POSTAGE
NECESSARY IF
MAILED IN THE
UNITED STATES
BUSINESS REPLY MAIL
FIRST CLASS MAIL PERMIT NO. 11663 WASHINGTON, DC
POSTAGE WELL BE PAID BY ENVIRONMENTAL PROTECTION AGENCY
INDOOR AIR DIVISION (ANR-445W)
U.S. ENVIRONMENTAL PROTECTION AGENCY
401 M ST SW
WASHINGTON DC 20277-1663
Inlilll lillmllinlmllilLllinillnlliil
NO POSTAGE
NECESSARY IF
MAILED IN THE
UNITED STATES
BUSINESS REPLY MAIL
FIRST CLASS MAIL PERMIT NO. 11663 WASHINGTON, DC
POSTAGE WILL BE PAID BY ENVIRONMENTAL PROTECTION AGENCY
INDOOR AIR DIVISION (ANR-445W)
U.S. ENVIRONMENTAL PROTECTION AGENCY
401 M ST SW
WASHINGTON DC 20277-1663
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ATTENTION: Building Owners and Managers * Health and Safety Professionals * Operating Engineers
Find out about indoor air quality problems and how to prevent or correct them with -
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A Guide for Building Owners
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This EPA/NIOSH indoor air quality guide provides valuable information on how to:
* Develop a building profile that can help you prevent indoor air quality problems
* Create an indoor air quality management plan
* Identify causes and solutions to problems as they occur
* Identify appropriate control strategies
* Decide whether you need outside technical assistance.
You'll also find sections covering:
* Key problem causing factors
* Air quality sampling
* Heating, ventilating, and air conditioning systems
* Moisture problems
* Where to find additional sources of information
...and much more!
Building Air Quality contains a wide variety of practical checklists and forms that can help
ou manage indoor air quality and diagnose problems. It's in looseleaf format, so you can easily
remove those pages for onsite use, and it comes with tabbed dividers for quick reference.
Building Air Quality gives you the current, comprehensive information you need to develop
an effective indoor air quality program. Order now! Just use the handy order form below.
order processing code: Superintendent of Documents Order Form Charge your order. i7""x"
*6103 It's Easy! fcg
To fax your orders (202) 512-2250
d YES, please send me copies of BUILDING AIR QUALITY: A GUIDE FOR BUILDING
OWNERS AND FACILITY MANAGERS, S/N 055-000-00390-4 at $24.00.
The total cost of my order is $ . International customers please add 25%. Price includes regular domestic
postage and handling and is subject to change. A 25% discount is available on purchases of 100 or more copies sent to a
single address.
Please Choose Method of Payment:
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May we make your name/address available to other mailers? Q r~j P.O. Box 371954, Pittsbur^l, PA 15250-7954
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ISBN 0-16-035919-8
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90000
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