Version 0, August 30, 2006
Environmental Technology Verification
Generic Verification Protocol for Biological and Aerosol Testing
of General Ventilation Air Cleaners
EPA Cooperative Agreement R-83191101
Research Triangle Institute Project 09309
Prepared by:
Air Pollution Control Technology Center
Research Triangle Institute
Research Triangle Park, NC
Approved by:
APCT Center Director: Signed by Andrew Trenholm, August 21, 2006
Andrew Trenholm
APCT Center Quality Manager: Signed by Gary Eaton, August 21, 2006
W. Gary Eaton
EPA Project Officer: Signed by Michael Kosusko, August 30, 2006
Michael Kosusko
EPA Quality Manager: Signed by Paul Groff, August 30. 2006
Paul Groff
KRTI
INTERNATIONAL
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TABLE OF CONTENTS
Table of Contents iii
List of Figures v
List of Tables v
List of Acronyms/Abbreviations/Definitions vii
1.0 Introduction 1
1.1: Environmental Technology Verification Program 1
1.2: Air Pollution Control Technology Verification Center 2
2.0: Verification Description 2
2.1: Identification and Acquisition of Devices 3
2.2: Performance of ASHRAE 52.2-1999 Test 4
2.3: Performance of Culturable Bioaerosol Testing 4
2.4: Performance of Inert Particle Testing 4
2.5: Preparation of Report 5
2.6: Data Quality Objectives and Criteria for Measurement Data 5
2.7: Special Training Requirements/Certification 6
2.8: Documentation and Records 6
2.8.1: Laboratory Documentation 6
2.8.2: Reporting 7
2.8.3: Verification Reports and Verification Statements 7
3.0 Test Program 8
3.1: Test Design 8
3.1.1: ASHRAE 52.2-1999 and Inert Testing 8
3.1.2: Culturable Bioaerosol Testing 10
3.2: Sampling Methods Requirements 12
3.3: Sample Handling and Custody Requirements 12
3.4: Analytical Methods Requirements 12
3.5: Quality Control Requirements 12
3.6: Instrument/Equipment Testing, Inspection, and Maintenance Requirements 12
3.7: Instrument Calibration and Frequency 12
3.8: Inspect!on/Acceptance Requirements for Supplies and Consumables 13
3.9: Data Management 13
3.9.1: Data Recording 13
3.9.2: Data Analysis 13
3.9.3: Data Storage and Retrieval 15
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References 16
Appendix A: Test Specifications 18
Appendix B: Inert Aerosol Run Sheet 24
Appendix C: Bioaerosol Run Sheet 26
LIST OF FIGURES
Figure Al. Schematic of test duct (top view) used for device testing 18
LIST OF TABLES
Table 1. DQOs for Inert Aerosol Tests 5
Table 2. DQOs for Filtration Efficiency for Culturable Bioaerosol 5
Table Al. Quality Control Parameters for Inert Aerosol Tests 19
Table A2. Quality Control Parameters Associated with Scanning Mobility Particle Sizer (SMPS)
and Conditioning Aerosol 21
Table A3. Quality Control Parameters for Bioaerosols 22
Table A4. Quality Control Parameters for the Test Duct 24
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List of Acronyms/Abbreviations/Definitions
Page v
ADQs
AGI
ANSI
ASHRAE
ASME
cm3
CPU
cfm
cm
CPC
culturable
CV
dso
DQO
EI, £2, £3
electret
EPA
Eq.
ETV
g
HEPA
in.
ISO
KC1
Kr
L
m3
MERV
min
min.
ML
m
mL
mm
MSDS
MS2
audits of data quality
all glass impinger
American National Standards Institute
American Society of Heating, Refrigerating, and Air-conditioning
Engineers
American Society of Mechanical Engineers
cubic centimeter(s)
colony forming unit
cubic feet per minute
centimeter(s)
condensation particle counter
able to be grown on microbiological media
coefficient of variance
50% cut point on Andersen sampler
data quality objective
average minimum particle-size efficiency designator of ASHRAE
a filter comprised of fibers that contain an embedded electrostatic
52.2
charge
U.S. Environmental Protection Agency
equation
Environmental Technology Verification Program
gram(s)
high efficiency particulate air
inch(es)
International Organization for Standardization
potassium chloride
Krypton
liter(s)
cubic meter(s)
minimum efficiency reporting value of ASHRAE 52.2
minimum
minute(s)
microbiology laboratory
meter(s)
milliliter(s)
millimeter(s)
material safety data sheet
bacterial virus or bacteriophage
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Page vi
OPC
PCO
PEs
PFU
PSE
psig
PSL
QA
QC
QM
QMP
RH
RTI
sec
SMPS
SOP
t
T/QAP
TSAs
//m
optical particle counter
photocatalytic oxidation
performance evaluations
plaque forming unit
particle size (removal) efficiency
pounds per square inch gauge
polystyrene-latex
quality assurance
quality control
quality manager
quality management plan
relative humidity
Research Triangle Institute
second(s)
scanning mobility particle counter
standard operating procedure
temperature
test/quality assurance plan
technical system audits
micrometer
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1.0 INTRODUCTION
The U.S. Environmental Protection Agency (EPA) established the Environmental Technology
Verification Program (ETV) in 1995. Under a cooperative agreement with EPA/ETV, Research
Triangle Institute (RTI) operates the Air Pollution Control Technology Verification Center
(APCT), and developed this protocol to verify filtration efficiency and bioaerosol collection
and/or inactivation efficiency of heating, ventilation and air conditioning (HVAC) air cleaners
for culturable bioaerosol and aerosol challenges.
This protocol describes the ETV considerations and requirements for verification of in-duct air
cleaners based on filtration, ultraviolet (UV) illumination, photocatalytic oxidation (PCO) and
combinations of those technologies. At this time the test plan is for filters, however an addendum
will be added as needed to test other devices. The protocol can be used for UV, PCO and other
technologies if they are compatible with the test facilities and procedures of the protocol. It is
anticipated that the devices tested will be compatible with a nominal 24" x 24" test duct cross
section.
This protocol is based on previous work for three ETV-related projects. Stakeholder groups were
convened under these projects to provide input into the selection of technologies and into the
development of protocols and test/quality assurance plans (T/QAPs).
• Under the ETV Indoor Air Pilot, a test protocol1 and test plan2 were developed and validated
for general ventilation media devices.
• As part of the ETV Safe Buildings for homeland security, a test protocol3 and test plan4
developed which included bioaerosol testing.
• Recently, the EPA Technology Testing and Evaluation Program (TTEP) developed a test
plan for testing UV light systems used in ventilation ducts for bioaerosols5.
The methods and procedures in these documents were supplemented based on RTFs experience
conducting testing for commercial clients for bioaerosols and testing based on American
National Standards Institute (ANSI)/American Society of Heating, Refrigerating and Air-
Conditioning Engineers, Inc. (ASHRAE) Standard 52.2-19996, Method of'Testing General
Ventilation Air-Cleaning Devices for Removal Efficiency by Particle Size (ASHRAE 52.2-1999).
1.1 Environmental Technology Verification
EPA through its Office of Research and Development (EPA-ORD) instituted the ETV Program
to verify the performance of innovative and improved technical solutions to problems that
threaten human health or the environment. EPA created the ETV Program to accelerate the
entrance of new and improved environmental technologies into the marketplace. It is a
voluntary, nonregulatory program. Its goal is to verify the environmental performance
characteristics of commercially ready technologies through the evaluation of objective and
quality-assured data so that potential purchasers and permitters are provided with an independent
and credible assessment of what they are buying and permitting.
The ETV Program does not conduct technology research or development. ETV test results are
always publicly available, and the applicants are strongly encouraged to ensure prior to
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beginning an ETV test that they are satisfied with the performance of their technologies. Within
the ETV Program, this state of development is characterized as "commercially ready."
The provision of high-quality performance data on a commercial technology encourages more
rapid implementation of that technology and consequent protection of the environment with
better and less expensive approaches.
1.2 Air Pollution Control Technology Verification Center
EPA's partner in the Air Pollution Control Technology Verification Center (APCT) is the
Research Triangle Institute (RTI), a nonprofit contract research organization with headquarters in
Research Triangle Park, NC. The APCT verifies the performance of commercially ready
technologies used to control air pollutant emissions. In addition to indoor air quality, APCT
include technologies for controlling particulate matter (PM), volatile organic compounds
(VOCs), nitrogen oxides (NOx), and hazardous air pollutants (HAPs) from both mobile and
stationary sources. The activities of the APCT are conducted with the assistance of stakeholders
from various interested parties. Overall, APCT guidance is provided by the Stakeholders
Advisory Committee (SAC), whereas the detailed development of individual technology ETV
protocols is conducted with input from technical panels focused on each technology area.
2.0 VERIFICATION DESCRIPTION
This ETV protocol describes the test and QA procedures that will be used to provide data on the
removal efficiency of bioaerosols and inert aerosols by general ventilation air cleaners.
While data and methods are available for measuring single-pass inert particle removal
efficiencies of air cleaners and filters, no standard method exists for evaluating culturable
bioaerosol reduction by these devices. RTI has developed a test method for measuring culturable
bioaerosol filtration efficiencies of devices ranging from a room air cleaner to duct-mounted
ventilation filters to vacuum cleaner filters7'8'9. Additionally, the method was used in a previous
ETV project for Biological Testing of General Ventilation Filters (EPA Contract No.
GS10F0283K-BPA-1; Task Order 1101. Research Triangle Institute Project 08787.001)4.
The methods discussed in the previous paragraph are the basis for the bioaerosol test and the sub-
0.3 |im inert particle tests in this protocol. Inert particle efficiency tests are used also as a point
of comparison for quality assurance (QA)/quality control (QC) of the culturable bioaerosol
results and will be used as a "self-consistency" check within the QA framework for the
bioaerosol tests.
This protocol describes the following tests:
1. A complete ASHRAE 52.2-1999 test,
2. Bioaerosol test with four culturable microorganisms,
3. Inert particle tests, using potassium chloride (KC1) aerosol:
a. 0.3 - 10 |im, with optical particle counter (OPC) measurement,
b. 0.03 - 0.3 |im, with scanning mobility particle counter (SMPS) measurement, and
c. 0.03 - 10 |im, with combined SMPS and OPC measurements.
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The above tests will be performed on clean, conditioned and dust-loaded devices as defined in
this paragraph. For options 2 and 3, conditioning with the sub-micron aerosol and dust loading
with ASHRAE dust will be required for all devices that incorporate filter media. Filter media is
the fibrous material used in air filters and other air cleaners to remove particles via filtration.
Examples include microglass and polypropylene fibers. Filter media is typically assembled in
the form of a flat panel, pleated or bag configuration.
Both conditioning and dust loading of filters are done so that the testing better represents what
happens when filters are used in real life. Most media filters increase in efficiency as they are
used and dust collects on the media. Electret filters have an electrostatic charge applied during
manufacturing. These filters may decrease in efficiency at the start of their use cycle and,
possibly, throughout the use cycle if the filters are replaced before significant loading (dust
accumulation) occurs. For ASFIRAE 52.2-1999, the conditioning step (also called the first
dustload) challenges the filter with ASFIRAE dust (a mixture of carbon black, cotton linters, and
Arizona road dust) until either a pressure drop increase of 10 Pa is achieved or 30 g of dust is
fed, whichever one comes first. Relative to the 25%, 50%, 75% and 100% dust load steps used in
the ASHRAE 52.2-1999 test, this is a very low dust challenge intended to simulate dust loading
during the early states of the filter's use. The dust loading with ASFIRAE dust is used to
simulate the changes that can occur as a media filter accumulates dust; this usually results in an
increase in efficiency, but can lead to an efficiency decrease if the filter sheds the dust instead of
retaining it.
The recommended submicron conditioning step was recently developed as a way to more closely
mimic the actual drop-off in efficiency as seen for electret media. Where the ASFIRAE 52.2-
1999 conditioning step may show a decrease in efficiency for these filters, it is usually much less
than that shown in situ and is unlikely to show a drop-off for the larger particle sizes even though
many media filters do drop-off in efficiency across the entire particle size range. Thus this step
is needed to simulate real use efficiencies.
Device-specific handling or additional measurements may be necessary for some devices.
All of these tests will be performed in a fully qualified ASHRAE 52.2-1999 test duct. This test
duct operates at positive pressure to minimize infiltration of room air or bioaerosol. The KC1
aerosol used for the ASFIRAE 52.2-1999 and other inert aerosol tests and the bioaerosols are
injected upstream of a mixing baffle to provide aerosol mixing with the airstream. Bioaerosol
and inert aerosol concentrations are measured both upstream and downstream of the test section
where the air cleaner is installed to obtain the challenge and penetrating concentrations,
respectively. The bioaerosol test includes inert testing, as applicable, for QA/QC and reporting
purposes.
2.1: Identification and Acquisition of Devices
Devices will be selected by the manufacturers and shipped to the testing facility. The full name
and description of the product will be provided. If a media device, a separate filter (or device)
will be provided for each ASFIRAE 52.2-1999 test; the bioaerosol tests and inert test may be
performed on the same filter if desired. For devices with filters, each manufacturer will provide
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a backup filter to be used if, for example, the other filters are damaged in transit. A custodian of
the devices will be responsible for storage, labeling, etc. of the devices. For non-media devices,
which tests are appropriate and how many units are needed will need to be determined on an
individual basis in consultation between the manufacturer and the testing personnel.
2.2: Performance of ASHRAE 52.2-1999 Test
The ASHRAE 52.2-1999 test will be performed per the standard and will establish the minimum
efficiency reporting value (MERV) and other parameters as required in the standard. ASHRAE
designed the MERV to represent a filter's minimum performance over multiple particle sizes. In
general, a higher MERV indicates higher filter efficiency. Most commercial filters and high end
residential filters are now marketed using the MERV. The filtration efficiencies (average of the
minimum composite efficiency) are presented by particle size groupings: El, 0.3 to 1.0 //m; E2,
1.0 to 3.0 //m; and E3, 3.0 //m to 10 //m. If other tests are performed on the same model of
device, performing the ASHRAE 52.2-1999 test should yield a consistent set of MERV, inert
efficiency and bioaerosol efficiency measurements for a device type.
2.3 Performance of Culturable Bioaerosol Testing
Biological testing will be performed using four different bioaerosols and one inert aerosol, if
appropriate. If ASHRAE 52.2-1999 testing is also performed, a second device will be used for
the bioaerosol testing if the device contains media. First, the initial efficiency will be determined
using both the biological and the inert aerosols. The inert testing will cover the typical ASHRAE
52.2-1999 particle size range of 0.3-10 jim. If the device contains media, the initial efficiencies
will be followed by
• Submicrometer conditioning (if applicable, see Section 2.0) and the biological efficiency will
be determined after conditioning,
• The device will then be loaded with ASHRAE test dust (if applicable, see Section 2.0) to
obtain the final pressure drop as appropriate based on the MERV estimated by the inert
particles or as chosen by the manufacturer. The bioaerosol efficiencies after dust-loading
will be determined. Table 12-1 of the ASHRAE 52.2-1999 standard provides information on
the minimum final resistance to be used for each MERV value.
The specifics of the testing will be discussed in further detail in Section 3.1.2.
2.4 Performance of Inert Particle Testing
Inert testing will be performed using KC1 aerosol on the device when (1) clean and, if applicable
(see Section 2.0), (2) conditioned and (3) fully dust-loaded. The device is fully dust-loaded when
the minimum final resistance is reached as specified in Table 12-1 of the standard. If ASHRAE
52.2-1999 testing is performed, a different device will be used for this testing if the device
contains media. If the bioaerosol testing is performed, this testing may be interspersed with that
testing. First, the initial efficiency will be determined using KC1 generated by the ASHRAE 52.2
method and by a Collison nebulizer. The standard generation method will be used with testing
with the OPC covering 0.3-10 jim; the nebulizer will be used with the SMPS to cover the particle
size range of 0.03-0.3 i^m. If applicable (see Section 2.0), the initial efficiencies will be followed
by:
• Submicrometer conditioning with the inert efficiency to be determined after conditioning
and between conditioning steps,
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• The device will be loaded with ASHRAE test dust to obtain the final pressure drop as
appropriate based on the MERV estimated by the inert particles (Table 12-1 of the standard)
or as chosen by the manufacturer; the inert efficiencies after dust-loading will be
determined.
The specifics of the testing will be discussed in further detail in Section Bl.l.
2.5: Preparation of Report
The final step is to complete the verification report and verification statement for each product
and test performed and submit them to the EPA.
2.6: Data Quality Objectives and Criteria for Measurement Data
Data quality objectives (DQOs) are qualitative and quantitative statements designed to ensure
that the type, quality, and quantity of data used are appropriate for the intended application. The
DQOs for the critical measurements are found in Tables 1 and 2. The test specifications are
found in Appendix A.
Table 1. DQOs for Inert Aerosol Tests
Parameter
Frequency and
description
DQO
OPC (optical particle
counter): Penetration
error limit for OPC
data
Each test. Statistical check of
data quality. Expected to be
achieved on tests of clean air
cleaners. May not always be
achieved with dust-loaded air
cleaners if the air cleaner sheds a
significant amount of the
collected dust.
Per definitions and procedures of ASHRAE 52.2
Section 10.6.46
a — -:= < 0.07P or 0.05 whichever is greater for 0.3 — 3 fjm
^ 0.15P or 0.05 -whichever is greater for 3 - 5.5 /urn
^ 0.20P or 0.05 whichever is greater for 5.5 — 10
T = T-distribution variable, n = number of samples,
P = penetration (fraction), o = standard deviation
Table 2. DQOs for Filtration Efficiency for Culturable Bioaerosol
Parameter
Minimum upstream counts for
samplers
Maximum counts for samplers
100% Penetration
(correlation test)
Upstream CPUs
Frequency and description
Each efficiency test.
Each efficiency test.
Performed at least once per
test sequence per organism.
Each test. Statistical check of
data quality.
Control Limits
Minimum of 10 CFUVplate or
PFUb/plate
Maximum of 500 CFU/plate or 800
PFUb/plate
Test Acceptable
Organism Penetration Range
B. atrophaeus 0.85 to 1.15
& A,versicolor
S. marcescens 0.80 to 1.20
MS2 0.75 to 1.25
cv1: < 0.25
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Parameter
Upstream PFUs
Frequency and description
Each test. Statistical check of
data quality.
Control Limits
CVC< 0.35
a CPU = colony forming units
b PFU = plaque forming unit
°CV = coefficient of variance
All data will be reviewed for accuracy (correctness) and reasonableness. If the results are
deemed unreasonable by the senior technical staff (e.g., internally inconsistent), they will be
discarded, the procedures reviewed, and the test repeated if necessary. Occasional data points
within a test are obvious outliers and will be discarded based on the statistical tests described in
and/or referenced by ASTM Standard Practice E 178-02, Standard Practice for Dealing with
Outlying Observations10 without requiring the entire test to be repeated. While exact agreement
is not expected (due to the different measurements devices) similar results are expected.
2.7: Special Training Requirements/Certification
There are no specialized certification requirements specified for these tests. The method chosen
for analysis of the inert aerosol particle size efficiency of ventilation devices in the laboratory is
restricted to use by, or under the supervision of, personnel experienced in the use of an OPC,
SMPS and skilled in the interpretation of raw count data.
In addition, for the bioaerosol tests, personnel should have completed at least one formal
microbiology course (college or professional/society sanctioned) and gone through extensive
informal laboratory training in the microbiology techniques needed for this task.
2.8: Documentation and Records
This section identifies the documents and reports to be generated as part of the verification
program and the information to be included in the verification reports and verification
statements. A description of the data management system established for this task is presented in
Section 3.9.
Requirements for record keeping and data management for the overall program are found in the
U.S. EPA, Environmental Technology Verification Program Quality Management Plan
11
2.8.1: Laboratory Documentation
ASHRAE 52.2-1999 and Inert Aerosol Tests
The test operator for the inert aerosol test will record the test data and run notes on test run sheets
prepared specifically for these tests (An example is presented in Appendix B.) The sheets will be
kept in a labeled three-ring binder. The run sheets are designed to prompt the test operator for all
required test information:
• Testing date, time, and operator;
• Manufacturer and model number of device;
• Physical description of the device;
• QA checks on the equipment and data; and
• Test conditions (temperature, relative humidity, atmospheric pressure, air flow rate, device
pressure drop).
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The particle count data generated by the OPC are recorded by the computer. The file will be
saved to the hard drive and later copied to a floppy disk or shared directory for backup.
Bioaerosol Tests
The bioaerosol test operator will record the test data and notes on a bioaerosol test run sheet
(presented in Appendix C). The sheets are kept in a labeled three-ring binder. The run sheets are
patterned from the inert aerosol run sheets and designed to prompt the test operator for all
required test information:
• Device and run number;
• Testing date and operator;
• Test conditions (t, RH, ambient pressure, air flow rate, pressure drop across ASME nozzle;
• Biological suspension information (test organism, suspension preparation, drying air,
nebulizer pressure, initial volume, and time on);
• Biological sampling scheme (time run begins, sample length, and media); and
• Rotameter readings showing the flow rate through the bioaerosol sampler.
The organism counts are entered in the project notebook or recorded by a computer. If recorded
to a computer, the file will be saved to the hard drive and later copied to a floppy disk or shared
directory for backup.
2.8.2: Reporting
After the completion of verification tests, the control test data, sample inventory logs, calibration
records, and certificates of calibration will be stored. Calibration records will include such
information as the instrument being calibrated, raw calibration data, calibration equations,
analyzer identifications, calibration dates, calibration standards used and their traceabilities,
identification of calibration equipment used, and the staff conducting the calibration. Final
reports of self-assessments and independent assessments (i.e., technical systems audits,
performance evaluations, and audits of data quality — TSAs, PEs, and ADQs — will be
retained. Each verification report and verification statement will contain a QA section, which
will describe the extent that verification test data comply with DQOs.
2.8.3: Verification Reports and Verification Statements
Verification reports and verification statements will be prepared, reviewed and submitted to the
EPA for approval. Procedures for the preparation, review, and dissemination of verification
reports and verification statements are described in the U.S. EPA, Environmental Technology
Verification Program Quality Management Plan11.
It is anticipated that the verification reports and statements will include the filtration efficiency
and/or bioaerosol collection/inactivation efficiency of the tested device for the challenges used
for the clean, and when containing a filter the conditioned and dust-loaded, device.
The following information will be included in the verification reports and verification
statements, depending on which test(s) were performed:
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• The fractional filtration efficiency of the air device over the 0.03 - 10 i^m size range for the
device when (1) clean, and if applicable (see Section 2.0) (2) conditioned and (3) fully dust-
loaded;
• The collection/inactivation efficiency for the four bioaerosols;
• The pressure drop across the clean and (if applicable, see Section 2.0), fully dust-loaded
device;
• The test air flow rate;
• The measured MERV and the associated El, E2, and E3 values of the ASHRAE 52.2-1999
test;
• A complete ASHRAE 52.2 report, and
• A description and photograph of the device tested.
3.0 MEASUREMENT/DATA ACQUISITION
3.1: Test Design
Under this protocol, the following tests may be performed:
1. A complete ASHRAE 52.2-1999 test,
2. Bioaerosol test with four culturable microorganisms,
3. Inert particle tests, using KC1 aerosol:
a. 0.3 - 10 jam, with OPC measurement,
b. 0.03-0.3 |im, with SMPS measurement, and
c. 0.03- 10 jam, with combined SMPS and OPC measurements.
The above tests will be performed on clean, conditioned and dust-loaded devices as applicable.
Conditioning with the sub-micron aerosol and dust loading will be required for all devices that
incorporate filter media. All tests will be performed on devices at an air flow rate acceptable
under ASHRAE 52.2-1999.
3.2: ASHRAE 52.2-1999 and Inert Testing
The ASHRAE 52.2-1999 test will be run in accordance with the ASHRAE 52.2-1999 test
method. A second device will be tested with modified ASHRAE 52.2-1999 procedures to extend
the measurements to smaller particle sizes and to condition electret media. All the inert aerosol
tests will use laboratory-generated KC1 particles dispersed into the airstream as the test aerosol.
A particle counter will measure and count the particles in a series of size ranges both upstream
and downstream of the test devices for its efficiency determinations. To simulate the effects of
dust accumulation on the devices, the devices will be tested when clean and, if applicable (see
Section 2.0), when conditioned and when fully dust-loaded. The dust-loading will follow
ASHRAE 52.2-1999 procedures as applicable.
Particle Counters
For the inert aerosol filtration efficiency measurements, the particle sizing measurements will be
made with two particle counting instruments: a Climet Model 500 spectrometer (OPC) or
equivalent OPC covering the particle diameter size range from 0.3 - 10 //m in 12 particle sizing
channels and a TSI SMPS or equivalent to cover the range from 0.03 - 0.3 //m. For the
conditioning aerosol, a TSI condensation particle counter (CPC) (model 3022A or similar) or the
equivalent will be used to monitor the upstream concentration. The CPC will function to
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monitor the concentration of the submicrometer-sized particles used for conditioning; it will not
aid in measuring the efficiency of the devices.
The OPC uses a laser-light illumination source and has a wide collection angle for the scattered
light. The OPC's sampling rate is 7.1 L/min. (0.25 cfm). The OPC is equipped to provide a
contact closure at the end of each sample and also provides a 15 sec. delay in particle counting
after each sample. The contact closure is used to control the operation of electromechanical
valve actuators in the upstream and downstream sample lines. The 15 sec. delay allows time for
the new sample to be acquired. The SMPS consists of a TSI Model 3080 electrostatic classifier
and a TSI Model 3010 or 3022 CPC.
Depending upon the quality of the data from any individual test, the SMPS can sometimes
reliably quantify particles even smaller than 0.03 //m, and when this is the case, those smaller
sizes are reported. The ability to quantify sizes smaller than 0.03 //m is determined as defined in
Table A2. A data control parameter for the SMPS requires that the coefficient of variance (CV)
on upstream counts be computed for each efficiency test based on the upstream particle counts
and that the CV be less than 0.30 before the data is used. The lower size ranges for the SMPS are
included in the verification report only if they meet the data control parameter. Particle sizes
above 0.3 jim will be measured and reported when there are particle counts that meet the data
specifications; however, the aerosol generation system necessary to meet our data standards
often does not achieve sufficient particle counts for the larger particles.
Inert Aerosol Generation
Three aerosol generators will be used for the tests as applicable. These generators are needed to
cover the range of particle sizes needed; one for the 0.03 - 0.3 //m tests, one for the 0.3 - 10 //m
tests, and one to generate the submicrometer conditioning aerosol. All of the aerosols will be
generated from KC1 in aqueous solution. The concentrations of KC1 will vary as will the
generation technique to give particles in the needed size ranges.
For the 0.3-10 //m efficiency tests, the KC1 solution will be nebulized using a two-fluid (air and
liquid) atomizing nozzle (Spray Systems 1/4 J siphon spray nozzle). The full description of the
test duct is in Appendix A. The nozzle is positioned at the top of a 0.30 m (12 in.)-diameter, 1.3
m (51 in.)-tall transparent acrylic spray tower. The tower serves two purposes. It allows the salt
droplets to dry by providing an approximately 40 sec. mean residence time, and it allows larger
particles to fall out from the aerosol. After generation, the aerosol passes through a TSI Model
3054 aerosol neutralizer (Krypton-85 radioactive source) to neutralize any electrostatic charge on
the aerosol (electrostatic charging is an unavoidable consequence of most aerosol-generation
methods). The KC1 solution is fed to the atomizing nozzle at 1.2 mL/min. by a pump. Varying
the operating air pressure of the generator allows control of the output aerosol concentration.
For the 0.03 - 0.3 //m tests, the KC1 solution will be nebulized with a Collison nebulizer or
Laskin nozzle generator. Both of these devices generate smaller particles than the spray nozzle.
Inert Conditioning Procedure for Devices with Media Under Test Options 2 and 3
For the conditioning required for devices with filter media if tested under options 2 or 3, the
conditioning aerosol will be produced using a bank of Laskin generators nebulizing a 0.1% KC1
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aqueous solution (1 g KC1 to 1 L of water). Previous measurements have indicated that the
resultant aerosol is < 0.1 //m in mean diameter. Periodically during the conditioning portion of
the test, the device's efficiency will be measured (0.3 - 10 //m) to determine if the efficiency has
fallen to its minimum condition. Once the efficiency is at or near its minimum, the conditioning
will cease. The duration of conditioning and the concentration of the conditioning aerosol will
be monitored during the test.
3.1.2: Culturable Bioaerosol Testing
The bioaerosol testing methodology is based on many of the same principals as the inert
methodology. Bioaerosol testing uses the same test rig as the inert aerosol and gas-phase testing.
Bioaerosol is generated from a suspension of the test organism and the sampling is achieved
using bioaerosol samplers. The use of microorganisms as the challenge aerosol requires that a
number of technical issues be addressed. These include:
• Measuring the survivability and culturability of the organisms through the aerosol generation
and collection process;
• Determining whether the test organisms are being aerosolized as singlets with a narrow size
distribution;
• Generating the bioaerosol challenge in sufficient concentration to maintain the sampling
duration within the sample time limits of the bioaerosol sampler; and
• Establishing the generation protocol for the test organisms.
Test Organisms
For devices with a filter, the size and shape of the organisms selected for testing are important
because the organisms are aerosolized and their filtration efficiency determined. These
organisms naturally vary in both their sizes and shapes. Therefore, there is the need to select
organisms that reflect that natural diversity. For devices that inactivate bioaerosols, the test
organisms also cover a range of susceptibilities to the various inactivation mechanisms of the
device.
The bioaerosol tests will be conducted using four organisms: one fungal spore, one spore-
forming bacterium, one vegetative bacterium, and one virus. The fungal spore Aspergillus
versicolor, a 2 - 3.5 jim sphere, is frequently reported as a causative agent of hypersensitivity
pneumonitis and has been isolated from a number of problem buildings. The spore form of the
bacteria Bacillus atrophaeus (formerly B. subtilis var niger) is elliptically shaped with
dimensions of 0.7 - 0.8 x 1 - 1.5 |im. The organism is a ubiquitous environmental bacterium
found at high levels in soil and highly associated with indoor dust. Staphylococcus epidermidis
(0.5 - 1.5 |im sphere) is a common gram-positive organism and will be the representative
vegetative bacterium.
Human viruses are thought to be spread by airborne or droplet transmission. Because human
viruses can be expensive and cumbersome to work with, the bacterial virus (bactedophage) MS2
(0.02 - 0.03 //m), having approximately the same aerosol characteristics as a human virus, will
serve as a surrogate for the viruses of similar and larger size and shape.
Although the individual virus particles are in the submicrometer size range, the test particle size
planned for the virus tests will span a range of sizes (polydispersed bioaerosol). This test is not
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designed to study the removal efficiencies for single individual virus particles; rather, it is
designed to determine the removal efficiencies for virus particles as they are commonly found
indoors. A representative challenge would be a polydispersed aerosol containing the phage
because:
• The aerosols created from sneezing and coughing vary in size from < 1 to 20 //m12, but the
largest particles settle out and only the smaller sizes remain in the air for extended periods for
potential removal by an air cleaner;
• For some viruses (i.e., Coxsackie virus), few viruses have been found associated with the
smallest particles13; and
• Nearly all 1 - 2 //m particles are deposited in the respiratory tract, while larger particles may
not be respired.
Bioaerosol Preparation and Generation
Bacteria suspension preparation for the aerosolization process requires that the specific test
organism be grown in the laboratory and the suspension prepared for aerosol generation in the
test rig. The microbial challenge suspensions are prepared by inoculating the test organism on
solid or liquid media, incubating the culture until mature, wiping organisms from the surface of
the pure culture (if solid media), and eluting them into sterile nebulizing fluid to a known
concentration, corresponding to a concentration of approximately 1 x 107 CPUs (colony forming
units)/mL. Usually, trypticase soy agar (broth) will be used for the bacteria. Sabourauds Dextrose
Agar will be used for the fungus.
The phage challenge will be prepared by inoculating a logarithmic phase broth culture of the host
bacteria with phage and allowing it to multiply overnight or until the majority of the host bacteria
are lysed. The mixture is processed to collect and concentrate the phage. Then, the phage stock is
filter sterilized (0.2//m) to remove the bacteria. The phage stock will be used as the challenge
aerosol. The concentration of the phage stock will be approximately 1 x 1012 or higher plaque
forming units (PFU)/mL.
The challenge organism suspensions will be aerosolized using a Collison nebulizer (BGI,
Waltham, MA) at 15 psi air pressure. The Collison nebulizer generates droplets with an
approximate volume mean diameter of 2 //m. The particle diameter after the water evaporates
depends on the solids content of the suspension. Particle size is determined by the size of the
suspended particles (if singlets).
Upstream and downstream sampling of the bacteria and fungus will be accomplished using one-
stage Andersen viable bioaerosol samplers or all glass impingers (AGIs). The phage will be
collected in all glass impingers (AGIs). The one-stage Andersen sampler is a 400-hole
multiple-jet impactor operating at 28 L/min. The dso (50% cut point on Andersen sampler) is
0.65 //m. After sampling, the petri dishes will be removed from the sampler and incubated at
appropriate times and temperatures for the test organism being used. CPUs are then enumerated
and their identity confirmed. The AGI is a high velocity liquid impinger operating at a flow rate
of 12.3 - 12.6 L/min. The dso is approximately 0.3 //m. The AGI is the sampler against which
the other commonly used bioaerosol samplers are often compared. The AGI (containing
collection fluid) is plated and the CPUs or PFUs are enumerated.
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The experimental conditions and sampling times will be adjusted so that these samplers will be
used within their upper and lower sampling limits.
To quantify the microbial counts, the plates are incubated at the appropriate temperature and
time for the test organism (overnight to a week). Colonies or plaques are counted. A "positive-
hole" correction is applied14 to the one-stage Andersen data to correct for undercounting at high
concentrations.
3.2: Sampling Methods Requirements
Inert aerosol sampling method requirements and critical dimensions and configurations of the
test apparatus are specified in ASHRAE 52.2-1999. Bioaerosol sampling methodology will
comply where appropriate. Bioaerosol samplers are operated according to the manufacturer's
specifications. The vacuum pumps required for operating the samplers are calibrated.
3.3: Sample Handling and Custody Requirements Sampling and handling procedures will be
described in testing laboratory SOPs. These SOPS will address any anticipated failures and the
methods that will be employed to overcome these failures. Most of the methods are well-known
sampling methods; therefore, sampling failures are not anticipated. Supporting measurements,
such as temperature, relative humidity or atmospheric pressure, will be recorded in laboratory
data logs, run sheets or notebooks.
Upon receipt of the test devices, each will be serially numbered using a permanent marker (or
other means as appropriate). All devices will be stored in a secure, temperature and humidity
controlled room.
3.4: Analytical Methods Requirements
The analytical method requirements for the inert aerosol testing are described in ASHRAE 52.2-
1999. A testing facility will have its own SOPs for the biological analysis.
3.5: Quality Control Requirements
The apparatus will be tested to verify that the test rig and sampling procedures are capable of
providing quantitatively reliable particle size measurements. Appendix A contains quality
control information for inert aerosols (Table Al), the SMPSr (Table A2) and bioaerosols (Table
A3).
3.6: Instrument/Equipment Testing, Inspection, and Maintenance Requirements
Qualification tests will be conducted as required by the table shown in Appendix A. Typically,
these tests are run as part of each test run, monthly, biannually, or after a change that may alter
performance.
3.7: Instrument Calibration and Frequency
Calibration will be performed in accordance with the manufacturer's recommendations or
annually. Recommended instrument calibration frequencies are provided in the respective SOPs
and manufacturer's manuals.
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3.8: Inspection/Acceptance Requirements for Supplies and Consumables
Chemicals, supplies, and other consumables will be purchased from sources that have provided
high quality products to the laboratory in the past. Materials such as growth media will be
purchased from a single source to help ensure uniformity throughout the duration of the project.
All supplies will be inspected by the lab personnel.
3.9: Data Management
The work performed using this protocol will conform to the quality management plan for the
APCT Center15.
Guidelines for data management include the description, location, format, and organization of all
types of records. The senior technical staff will oversee all data management activities. This
section identifies the activities and processes planned for documenting the traceability of the
data, calibrations, and information in the verification report.
3.9.1: Data Recording
Data for this task will be collected either by computer or by manual (handwritten) entries.
Observations and records (e.g., sample description and collection information) will be recorded
manually in lab notebooks kept exclusively for this task. Output data generated by the OPC
instruments will be transferred directly to a computer file and stored as a spreadsheet; printed
output will be taped into the lab notebook.
3.9.2: Data Analysis
Inert Aerosol Data
The computation of inert aerosol filtration efficiency is based on the ratio of the downstream-to-
upstream particle concentrations corrected on a channel-by-channel basis for:
• Background counts (i.e., upstream and downstream counts observed when the aerosol
generator is off) and
• For the correlation ratio measured at the start of the test sequence.
A minimum of two background and six upstream and six downstream counts will be taken.
These data will be used for determining filtration efficiency by computing the observed
penetration (Pobserved) (Eq. 1):
(D-D,)
p _ ± t> ' p -:
observed /TJ TT \ 4'
where:
D = Downstream particle count,
Db = Downstream background count,
U = Upstream count, and
Ub = Upstream background count.
To remove system bias, the observed penetration is corrected by the correlation ratio (R) (the
measured during a blank control test for which no device is installed in the duct) (Eq. 2).
corrected ~ observed Eq. 2
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The inactivation efficiency is then computed (Eq. 3).
Inactivation Efficiency (%) = 1 00 (1 - Pcorrected ) Eq . 3
Bioaerosol Data
Data analysis will be performed using commercially available software (Microsoft Excel16) to
enter the raw data into a spreadsheet and calculate results from a series of equations.
Samples will be collected simultaneously using multiple samplers. A minimum of five, usually
ten, replicates will be collected for each efficiency determination.
The mean upstream and downstream CPUs will be calculated as (Eq. 4):
n n
_
*'=! and £> = *'=! Eq. 4
n n
where:
D; = Downstream count of the ith sample and n is the number of replicate samples
collected and
U; = Upstream count of the ith sample and n is the number of replicate samples
collected.
The calculation of the penetration is based on the ratio of the downstream to upstream culturable
counts. The penetration with the device installed in the test rig (Pmeasured) is shown in the
following equation (Eq. 5):
P = -
measured /U Eq. 5
where:
D = Mean downstream count with a device installed in the test rig and
U = Mean upstream count with a device installed in the test rig.
The PIOO (no device installed in the test rig or device turned off) is calculated as the Pmeasured but
using the results of the no device tests (Eq. 6).
P,m - Moo/ „ ,
~ 77 E. 6
^
where:
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Dwo = Mean downstream count with no device or device turned off in the test rig and
C/100 = Mean upstream count with no device or device turned off in the test rig.
To remove system bias, the Pmeasured is corrected by the penetration of a blank "no device" test for
which no air cleaner is installed in the duct (Pioo) (Eq. 7).
P /
p = measured/
corrected /P Eq. 7
/ 100 H
The collect!on/inactivation efficiency is then calculated as shown in Eq. 8.
Collection! Inactivation Efficiency (%) = 100 (1 - Pcomcted ) Eq. 8
The precision DQO for bioaerosol inactivation efficiency will be calculated based as ± one
standard deviation of penetration computed from the coefficient of variance of upstream and
downstream culturable counts as shown in Eq. 9.
Std. Deviation = Pmeasured (CV* + CFD2) Eq. 9
where:
Pmeasured = Penetration calculated from the upstream and downstream culturable counts,
CVu = Coefficient of variance for the upstream counts, and
CVo = Coefficient of variance for the downstream counts.
3.9.3: Data Storage and Retrieval
Laboratory notebooks containing manually recorded information and data output generated from
instrumentation will be stored in the custody of the appropriate technical lead for the duration of
the project.
Spreadsheet files including raw and calculated data will be stored on computers. The files will
be downloaded to a network server backed up nightly on magnetic tape.
ETV policy requires that project files be archived offsite at a secure facility for a minimum of 7
years following the end of the project.
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References
1. RTI. 1999. Environmental Technology Verification Test Protocol for General Ventilation
Filters. Research Triangle Park, NC. http://www.epa.gov/etv/pdfs/vp/07_vp_filters.pdf
2. RTI. 1999. Environmental Technology Verification Test Plan for General Ventilation Filters.
Research Triangle Park, NC.
http://www.epa. gov/etv/pdfs/testplan/07_tp_093099_general.pdf
3. RTI. 2004. Environmental Technology Verification Protocol for Measuring Efficiency for
Biological or Chemical Challenges of Technologies for Cleaning Building Ventilation Air.
Research Triangle Park, NC. Available from RTI.
4. RTI. 2003. Environmental Technology Verification Test Plan for Biological Testing of
General Ventilation Filters. Research Triangle Park, NC.
http://www.epa.gov/etv/pdfs/testplan/10_tp_bio.pdf
5. RTI. 2005. Technology Testing and Evaluation Program, Test/QA Plan for Bioaerosol
Inactivation Efficiency by HVAC In-Duct Ultraviolet Light Air Cleaners. Research Triangle
Park, NC. Available from RTI.
6. ANSI/ASHRAE (American National Standards Institute/American Society of Heating,
Refrigerating and Air-Conditioning Engineers). 1999. ANSI/ASHRAE Standard 52.2-1999,
Method of Testing General Ventilation Air-Cleaning Devices for Removal Efficiency by
Particle Size, Atlanta, GA.
7. Foarde, K.K. and J.T. Hanley. 2001. Determine the Efficacy of Antimicrobial Treatments of
Fibrous Air Filters. ASHRAE Transactions. Volume 107, Part 1. 156-170.
8. Foarde, K.K. and J.T. Hanley. 1999. A New Laboratory Method for Measuring the
Bioaerosol Filtration Efficiency of Air Cleaners. Proceedings: 1999 Air Filtration
Conference: Fall Topical Conference pp. 47-54.
9. Foarde, K.K., J.T. Hanley, D.S. Ensor, and P.F. Roessler. 1999. Development of a Method
for Measuring Single-Pass Bioaerosol Removal Efficiencies of a Room Air Cleaner. Aerosol
Science and Technology. 30: 223-234.
10. ASTM. 2003. E178-02 Standard Practice for Dealing With Outlying Observations. American
Society for Testing and Materials. West Conshohocken, PA.
11. U.S. EPA. 2002. Environmental Technology Verification Program Quality Management
Plan, EPA/600/R-03/021, U.S. EPA, Cincinnati, OH, 2002.
http://www.epa.gov/etv/pdfs/qmp/ETV 02 QMP.pdf
12. Knight, V. 1973. Viral and Mycoplasmal Infections of the Respiratory Tract, Lea & Febiger,
Philadelphia, PA.
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13. Buckland, F.E., and Tyrell, D.A.S. 1962. Loss of Infectivity on Drying Various Viruses,
Nature 195:1063-1064.
14. Macher, J.M. 1989. Positive Hole Correction of Multiple-jet Impactors for Collecting Viable
Microorganisms, American Industrial Hygiene Association Journal. 50: 561-568.
15.RTI (Research Triangle Institute). 2005. Quality Management Plan for Verification Testing
of Air Pollution Control Technology, Revision 2.2, Research Triangle Park, NC.
http://etv.rti.org/apct/pdf/apctqmp.pdf
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Page 18
Appendix A: Test Specifications
Test specifications for the inert aerosol tests are defined in ASHRAE 52.2-1999 and shown in
Table Al. These will be used for both the ASHRAE 52.2-1999 testing and the inert aerosol
component of the bioaerosol test. The test specifications associated with the SMPS and the
conditioning aerosol are found in Table A2. Table A3 shows the test specifications for the
bioaerosol test. The test duct performance specifications applicable to all testing are found in
Table A4.
Test Duct /System
A schematic of the test duct is shown in Figure Al. The drawing is approximately to scale. The
test duct is a 610 mm (24 in.) x 610 mm (24 in.) square. The locations of the major components,
including the sampling probes, test section (device holder), the aerosol generator (site of aerosol
injection) are shown.
There are presently no standards available to directly "calibrate" the test system for penetration.
However, a number of parameters can be checked to verify proper performance. 0% and 100%
penetration measurements are made by using a HEPA filter and an empty (no device) test
section, respectively, using the optical particle counter (OPC) and KC1 as the inert particulate.
Separate tests with the bioaerosol will be done using the test bioaerosol and the bioaerosol
samplers.
The flow rate will be measured via the pressure drop across an ASME long radius flow nozzle
(i.e., nozzle size 8V2 in.) mounted in the center of the duct downstream of the device. It will be
the primary standard for the laboratory. Prior to use, the nozzle is visually inspected to be free
from defects. The installation of the nozzle in the duct will be inspected to confirm that it is
seated in place.
Exhaust
to Room
Room X
Air " — '
1 '
H_
C^K^ Y 5
A S
h
t \
\ In lei
Blower \ BE
Flow Control
Valve
ASME Nozzle
Outlet Filter Bank 9
1 iff
if c[ 11
1 0(i ^ —
Filter / Upstream Mixer
Ae ro so 1 ^
Generator S=
Bio lo g ic a 1
Sampling Downstream Mixer
P ^
= *" '^
. )J
Pfvtice Eaokup Filter
; Section , ...
1 Holder(Used VMien
^ Dust-Loading)
D logical
mpling
Figure Al. Schematic of test duct (top view) used for filter testing. Drawing is
approximately to scale with the duct being 610x610 mm2 (24 x 24 in.2) and shows the
location of aerosol injection, mixing baffles, test section, ASME flow nozzle, and OPC
sampling probes.
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Page 19
The pressure drop across the device will be measured with an inclined manometer and/or a
digital micromanometer. The zero and level of the manometer will be confirmed and connecting
tubing inspected for integrity.
Measurements of the in-duct temperature and relative humidity (RH) and room atmospheric
pressure will be made. These measurements are not critical to the program and are being
collected simply to document the general test environment. A wet and dry bulb psychrometer
will be used for determination of temperature and relative humidity and an aneroid barometer for
atmospheric pressure (periodically compared to a mercury barometer in an adjoining lab). For
the bioaerosol, the RH goal is 20 - 70%. No specific quality control checks on these instruments
are planned other than an inspection of the instruments for mechanical faults (e.g., mercury
separation in the thermometers, poor tubing connections), and inspection of the data for
reasonableness.
Table Al. Quality Control Parameters For Inert Aerosol Tests
Parameter
Minimum counts per
OPCa channel for
challenge aerosol
Maximum total OPC
count per sample
100% Efficiency test
(0% Penetration)
100% Penetration
(correlation test)
Penetration error limit
for OPC data
OPC calibration:
primary calibration
Frequency and
description
For each efficiency test, the total
number of particles counted per
OPC sizing channel for the
upstream challenge aerosol is
computed.
Each efficiency test.
Monthly. A HEP A filter is used
for the test device.
A 100% penetration test
performed at least once per week
during testing.
Each test. Statistical check of
data quality. Expected to be
achieved on tests of clean air
cleaners. May not always be
achieved with dust-loaded air
cleaners if the air cleaner sheds a
significant amount of the
collected dust.
Primary calibration performed by
manufacturer at manufacturer-
specified intervals; but at least
annually.
Control Limits
Minimum total of 500 particle counts per channel.
Not to exceed maximum challenge aerosol concentration
determined in the OPC upper concentration limit test
referenced in Table A4.
Measured penetration must be <1%.
Particle Acceptable
Size range Penetration Range:
0.3tol|im: 0.90 to 1.10
Ito3|im: 0.80 to 1.20
3tolO|im: 0.70 to 1.30
Per definitions and procedures of ASEQIAE 52.2 Section
10.6.46
&—;= ^ 0.07 P or 0.05 whichever is greater for 0.3 - 3 /urn
v«
&—j= ^ 0.15P or 0.05 whichever is greater for 3 - 5.5 /u
v«
T
Manufacturer provides certificate of calibration.
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Page 20
Parameter
Minimum counts per
OPCa channel for
challenge aerosol
OPC sizing accuracy
check:
polystyrene latex
spheres (PSL)
OPC reference filter
check
OPC zero count
Background count rate
Pressure drop across
empty test section
Pressure drop across
the air cleaner
Pressure drop across
the ASME flow
nozzle used for
measurement of
airflow
Aerosol charge
neutralizer
Filter weight
Weight of ASHRAE
dust fed into the test
duct
Frequency and
description
For each efficiency test, the total
number of particles counted per
OPC sizing channel for the
upstream challenge aerosol is
computed.
Daily. Sample aerosolized PSL
spheres.
A filtration efficiency test is
performed on a reference filter
monthly during testing.
Each correlation and initial
efficiency test.
Measured during correlation and
clean device tests.
Each correlation test.
Annual. Compare to reference
manometer.
Annual. Compare to reference
manometer.
Monthly. Confirm activity of
radioactive charge neutralizers.
Confirm balance of corona
discharge neutralizers.
Filters will be weighed before
and after completion of dust
loading.
Each test based on the change in
weight of the dust on the dust-
loading tray.
Control Limits
Minimum total of 500 particle counts per channel.
Peak of distribution should be in correct OPC channel.
Efficiency must be consistent with reference filter
measurements made after OPC's primary calibration;
efficiency within ± 10 percentage points.
Less than 10 counts per sample.
Upper 95% confidence limit on background counts must
be less than 5% of challenge counts.
Measured pressure drop must be < 0.03 in. H2O.
Inclined fluid manometer or digital manometer readable to
within ±0.01 in. H2O. 10% or better accuracy.
Inclined fluid manometer or digital manometer readable to
within ±0.01 in. H2O. 10% or better accuracy.
Activity must be detected in radioactive neutralizers.
Corona discharge neutralizers must be in balance.
Electronic balance with 0.1 g resolution, 10% accuracy or
better, calibrated annually.
Electronic balance with 0.1 g resolution, 10% accuracy or
better, calibrated annually.
a OPC = optical particle counter
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Page 21
Table A2. Quality Control Parameters Associated with Scanning Mobility Particle Sizer
(SMPS) and Conditioning Aerosol
Parameter
0% Efficiency test
(100% Penetration)
SMPS: CVon
upstream counts
Conditioning aerosol
concentration
SMPS operational
checks:
sizing accuracy check
instrument flow rates
instrument zero —
filtered inlet
instrument zero — 0
volt setting
inlet impactor
photodetector
Reference flow meter
Reference manometer
Frequency and description
At least once every five efficiency
tests. A 100% penetration test is
performed with no device in the test
section.
Computed for each efficiency test
based on the upstream particle
counts.
Measured with a condensation
particle counter (CPC).
At start of project and at least
monthly during testing, sample
aerosolized monodisperse PSL
spheres.
Confirmed prior to test program
using reference flow meter.
Checked at start of project and
weekly during testing.
Checked at start of project and
weekly during testing.
Visually confirm impactor orifice is
free of debris and that the impactor
plate is greased. Daily.
Check at start of program. Filter on
CPC inlet and/or sample pump off.
Bios International Model DryCal
DC1 Primary Air Flow Meter
(soapless piston-type cell) or the
Gilabrator (good for lower
flowrates). Used to confirm SMPS
flow rates at beginning of program.
TSI Model 8702/8704 digital
manometer
and/or Meriam Model 50MH10-8
inclined fluid manometer.
Control Limit
Particle Acceptable
Size range Penetration Range:
0.01- 1.0 |im 0.70 to 1.30
<0.30
Concentration will not exceed instrument's
specified concentration limit.
A relative peak in the number distribution is
observed within 20% of the PSL particle diameter
Flows should be within 10% of set points.
< 0. 1 particle/cm3 a counted by CPC.
< 0.1 particles/cm3 counted by CPC.
Orifice clear of visible obstructions. Impactor has
very thin film of vacuum grease.
0 ± 0.05 volts
Based on the fundamental nature of this positive
displacement piston flow meter, the
manufacturer's accuracy claim is accepted. The
unit is visually inspected for proper operation prior
to use.
Digital manometer to receive primary calibration
by manufacturer within prior 12 months. Fluid
manometer inspected for zero and level.
a cm = cubic centimeter
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Page 22
Table A3. Quality Control Parameters for Bioaerosols
Parameter
Minimum upstream counts for
samplers
Maximum counts for samplers
100% Penetration
(correlation test)
Upstream CPUs
Upstream PFUs
Frequency and description
Each efficiency test.
Each efficiency test.
Performed at least once per test
sequence per organism
Each test. Statistical check of data
Each test. Statistical check of data
Control Limits
Minimum of 10 CFUVplate or
PFUb/plate
Maximum of 400 CFU/plate or 800
PFUb/plate
Test Acceptable
Organism Penetration Range:
B.subtilis 0.85 to 1.1 5
S. epidermidis 0. 80 to 1 .20
MS2 0.80 to 1.20
A. versicolor 0.85 to 1.15
CVC < 0.20
CVC< 0.35
a CPU = colony forming units
b PFU = plaque forming unit
0 CV = coefficient of variance
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Research Triangle Institute
ETV Protocol
Bioaerosol and Aerosol Testing of General Ventilation Air Cleaners
Table A4. Quality Control Parameters for the Test Duct
Page 23
Parameter
Air velocity uniformity based on traverse measurements over a nine-point
cross-sectional grid at the test flow rate. Performed upstream of the test
section using a TSI Model 8345 digital thermal anemometer.
Inert aerosol uniformity based on traverse measurements over a nine-point
cross-sectional grid at the test flow rate. Performed upstream of the test
section.
Inert downstream mixing based on nine-point perimeter injection grid at the
test section and center-of-duct readings at the downstream probe locations.
100% Efficiency test based on HEPA filter test.
100% Penetration (correlation test)
OPCb upper concentration limit based on limiting the concentration to below
the level corresponding to the onset of coincidence error.
Aerosol generator response time
Duct leakage
Ratio of leak rate to test flow rate.
Determined by sealing the duct at inlet HEPA filter bank and at the ASME
flow nozzle locations followed by metering in air to achieve a steady duct
pressure. The flow rate of the metering air (equal to the leakage flow) is
measured for a range of duct pressures.
OPC zero count check
OPC sizing accuracy check based on sampling aerosolized monodisperse
PSL spheres of known size.
Aerosol neutralizer activity (if radioactive source is used)
Dust feeder air flow rate as function of discharge pressure based on
measuring the required dust feeder air gauge pressure to achieve 425 L/min.
(15 cfm) airflow.
Final device efficiency
Based on injecting 100 g of dust and computing weight change of the filter.
Control Limits
CV < 10%
CV<15%
CV<10%
Efficiency > 99%
Particle Acceptable
Size range Penetration Range:
0.3tol|im: 0.90 to 1.10
Ito3|im: 0.80 to 1.20
3tolO|im: 0.70 to 1.30
No predetermined level, but must be
established prior to testing.
No predetermined level.
Ratio < 1.0%
< 10 counts per sample
Relative maximum must appear in
the appropriate sizing channel.
Radioactivity must be detected.
No predetermined value.
100 ± 2 g of dust captured for 100 g
injected.
' CV = coefficient of variance
' OPC = optical particle counter
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Research Triangle Institute
ETV Protocol
Bioaerosol and Aerosol Testing of General Ventilation Air Cleaners
Page 24
Appendix B: Inert Aerosol Run Sheet
Date:
Test Operator:
Staple photo to back of page 2.
_Charge Number:
Physical Description of Device:
Test Requested by:
Manufacturer:
Product Name:
Model:
Condition: New or From Field No damage or Slight frame damage and/or Media damage (Circle
all that apply)
Other/describe damage:
Product type:
Other Attributes:
Height
Width
Thickness
Media Type (if applicable)
Media Color (if
applicable)
Correlation Test: (use 3/3 -10/9 - 3/3 sampling)
Date: Time:
Flow rate manometer zeroed and level:
Device pressure drop manometer zeroed and level:
OPC clock correct:
Valve switch on:
OPC: (Set for 0.10 ft3 samples with 15 second purge; use 3/3 -10/9 - 3/3 sampling)
20 min
warm
up
/
Flow is
0.25
cfm
/
CI-226
switch
"Low"
/ or
n/a
Zero Check < 10 total / sample
enter actual count
HEPA capsule or In-duct
Daily PSL check
(Enter size when
performed or / if done
earlier today)
File Name
c:\climet\rpmmddyyss
RP MM DD YY SS
must meet <10 criteria at least once per ASHRAE 52.2 test.
Notify project manager if limit is exceeded.
** Save daily check to disk using file name.
RPMMDDYY-HEPA-PSL.TXT
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Research Triangle Institute
ETV Protocol
Bioaerosol and Aerosol Testing of General Ventilation Air Cleaners
Test Conditions:
Page 25
Flow rate
(cfm)++
Flow
Manometer
(inchH2O)
Dry Bulb
Temp. (F)
Limits = 50-100 °F
Wet Bulb
Temp.
(°F)
RH
Limits =
20-65%
Arm Pressure
(inches Hg)
XX. XX
Is flowrate MERV eligible for this size device? Y or N (see page 3)
Aerosol Generator: JNo-Device Pressure Dro
Aerosol
Type
KCL
Pump
setting
1.2cc/
min
Drying
Air
4 cfm
240 cfh
Nozzle
air
pressure
(psi)
Nozzle
air
flowmt.
p
Upper
Concentration
Target *
enter Ch 1 count
Lower
Concentration
target **
enter Ch 1 5 cnt
At start
of test
x.xx(x)
must be < 0.03"
At end of
test
x.xx(x)
must be < 0.03"
Channel 1 targets: CI-500 = 3,000; Cl-Spectro = 3,000; CI-226 = 5,000 Channel 15 target: 72
-150 counts per sample desired range. Notify project manager if these targets are not met.
Using "Correlation" graph in spreadsheet, does data look reasonable?
yes
no (Should be near 1.0)
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Research Triangle Institute
ETV Protocol
Bioaerosol and Aerosol Testing of General Ventilation Air Cleaners
Appendix C: Bioaerosol Run Sheet
Page 26
Device #:_
Date:
Run#:
Test Operator:
Climet Filename:
Test Conditions:
Test Flow Rate
CFM
ASME Nozzle
Pressure Drop
in. H2O
Temperature
°F
RH
%
Ambient Atm
Pressure
in. Hg
Biological Suspension:
Organism:
Suspension Prep:_
Drying Air:
Nebulizer Pressure:
Initial Volume:
Time On:
Biological Sampling:
Sample #
Time Run Begins
Sample Length (min.) Media
Ul, U2, U3
D1,D2, D3
D4, D5, D6
U4, U5, U6
U7, U8, U9
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Research Triangle Institute
ETV Protocol
Bioaerosol and Aerosol Testing of General Ventilation Air Cleaners
Page 27
D7, D8, D9
D10,D11,D12
U10,U11,U12
U; = upstream sample ;'
D; = downstream sample ;'
Rotometer/Vac #1 Reading:
Rotometer/Vac #2 Reading:
Rotometer/Vac #3 Reading:
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