United States
Environmental Protection
Agency
Research and Development
Air and Energy Engineering
Research Laboratory
Research Triangle Park, NC 27711
EPA/600/SR-93/218 January 1994
Project Summary
Characteristics of School
Buildings in the U.S.
Harry Chmelynski
A subsample of 100 schools from
the Environmental Protection Agency's
(EPA's) National School Radon Survey
were visited to obtain information on
building structure, location of utility
lines, and the type of heating, ventilat-
ing, and air-conditioning (HVAC) sys-
tem. Information from each school was
entered into a database to determine
the relative proportions of physical
characteristics of the U.S. school build-
ing population. Results indicate that
most school structures are of slab-on-
grade construction, gravel was used
as subslab fill material in approximately
50% of the structures, approximately
80% of the schools have either central
HVAC or unit ventilators capable of de-
livering conditioned outdoor air to the
classrooms, and almost 25% of the
schools have subslab footings extend-
ing both beneath the classroom walls
and along the corridors, thus compli-
cating the installation of effective sub-
slab depressurization systems. The re-
sults obtained in this study will be used
by the EPA to guide future mitigation
research in schools.
This Project Summary was developed
by EPA's Air and Energy Engineering
Research Laboratory, Research Tri-
angle Park, NC, to announce key find-
ings of the research project that is fully
documented in a separate report of the
same title (see Project Report ordering
information at back).
Introduction
To help guide future radon research in
schools and to better focus technical guid-
ance documents, the Air and Energy En-
gineering Research Laboratory (AEERL)
of EPA's Office of Research and Develop-
ment conducted a literature search to find
information that quantifies the physical
characteristics of U.S. school buildings.
Information specific to radon mitigation re-
search in schools was not found in any
existing reports or databases. As a result,
AEERL's Radon Mitigation Branch (RMB)
chose to characterize the U.S. school
building population using a sample of 100
schools from the National School Radon
Survey (NSRS). The schools are a na-
tionally representative random sample
selected by EPA's Office of Radiation and
Indoor Air.
The 100 schools were visited to obtain
information on building structure, location
of utility lines, and the type of heating,
ventilating, and air-conditioning (HVAC)
system. Information for each school was
entered into a database to determine the
relative proportions of physical character-
istics of the U.S. school building popula-
tion. To record the necessary information,
a building characteristic profile sheet was
completed for each school by RMB staff
engineers and selected contractors during
1991 and 1992.
The three-page profile sheet was devel-
oped for this project for on-site character-
ization of the structure, utility penetrations,
types of HVAC equipment, and other build-
ing features pertinent to radon diagnostics
and mitigation. Because many schools
have several contiguous structures often
constructed at different times and each
with its own unique characteristics, the
profile sheet was completed separately
for each structure. In a few cases, where
the structures are not contiguous but are
Printed on Recycled Paper
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campus-style complexes, profile sheets
were completed for each distinct structure
in the school, unless all were of the same
vintage and construction type.
Where available, building plans were
examined to determine structure and
HVAC system information that is not al-
ways available through on-site observa-
tion. Following inspection of the building
plans, the school was visited to verify in-
formation on the plans and to collect any
additional profile sheet information that was
not on the plans. Complete sets of con-
struction plans were available for only 40%
of the structures. When plans were not
available, the profile sheet was completed
based on discussions with school person-
nel and the judgement of the researchers.
The results of the survey provide many
significant findings concerning the distri-
bution of school building characteristics.
The profile sheets provide evidence of the
variety of building structures and HVAC
equipment found in typical schools. The
age of a school, number and size of dif-
ferent structures, type of substructure, lo-
cation of utility lines, and types of HVAC
equipment vary widely in the sample
schools.
Major Findings
Major findings of this study relative to
radon diagnostics and mitigation are:
• Over 70% of school structures have
slab-on grade construction;
• Gravel was used as subslab fill mate-
rial in approximately 45% of the struc-
tures with information available;
• Approximately 40% of schools have
a single type of HVAC system in all
classrooms;
• Approximately 80% of the schools
have either central HVAC or unit ven-
tilators capable of delivering condi-
tioned outdoor air to the classroom;
and
• While over 50% of the structures have
no internal subslab footings (thus fa-
cilitating mitigation with subslab de-
pressurization systems), almost 25%
of the structures have footings both
along corridor walls and between
classrooms (thus complicating the in-
stallation of subslab depressurization
systems).
The distribution of the profile sheet re-
sponses into the categories used for data
analysis required reducing detailed re-
sponses to shorter, categorical responses
for many of the profile sheet questions.
The original responses for each school
were entered into a dBase IV file, and a
separate file was created containing the
shorter categorical responses used for the
statistical analyses.
The full report discusses the random
sample selection procedures, describes the
information collected on the building char-
acteristic profile sheets, summarizes some
of the results recorded on the school pro-
file sheets, compares the results with those
observed in RMB's research schools, de-
scribes the accompanying dBase IV data
files, and presents the statistical limita-
tions of this study. The information col-
lected during this study may be useful to
EPA and others to guide future radon
mitigation research in schools.
•&U.S. GOVERNMENT PRINTING OFFICE: I9M • S94MM7/MM7
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Harry Chmelynski is with S. Cohen and Associates, Inc., McLean, VA 22101.
Kelly W. Leovic is the EPA Project Officer (see below).
The complete report, entitled "Characteristics of School Buildings in the U.S.,"
(Order No. PB94-121704; Cost: $19.50; subject to change) will be a vailable only
from:
National Technical Information Service
5285 Port Royal Road
Springfield, VA 22161
Telephone: 703-487-4350
The EPA Project Officer can be contacted at:
Air and Energy Engineering Research Laboratory
U.S. Environmental Protection Agency
Research Triangle Park, NC 27711
United States
Environmental Protection Agency
Center for Environmental Research Information
Cincinnati, OH 45268
Official Business
Penalty for Private Use
$300
BULK RATE
POSTAGE & FEES PAID
EPA
PERMIT No. G-35
EPA/600/SR-93/218
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