United States
Environmental Protection
Agency
Air and Energy Engineering
Research Laboratory
Research Triangle Park NC 27711
Research and Development
EPA/600/S2-85/047 June 1985
Project Summary
'/1
Literature Review and
Survey of Emissions from
Residential Wood
Combustion and Their Impact
M. W. Hartman and G. D. Rives
This report resulted from a literature
search of 53 reports covering wood-
stove design, operating conditions,
emissions, testing methods, and am-
bient air impacts. The woodstoves
studied varied in design from simple to
complex and included controlled (cata-
lytic) and uncontrolled woodstoves. The
primary considerations in operating
conditions were that the stoves studied
burned primarily cord wood. The results
of the tests were segregated according
to the type of wood utilized, the percent
moisture in the wood as tested, the burn
rate of the wood, the stage of burning
which was tested, and the length of the
test. In addition to the operating condi-
tions, the emissions were qualified by
the test method which was performed,
the firebox temperature, and the stack
temperature. Emission parameters stud-
ied included particulate matter (PM),
carbon monoxide (CO), nitrogen oxides
(NOĢ). hydrocarbons (HC), and polycy-
clic organic material (POM), especially
benzo-a-pyrene (BAP). This report in-
cludes ambient air impact surveys at
various locations in the U.S. Most
ambient studies were concerned with
the PM and HC impacts, but a few
looked at relating these impacts back to
their sources.
This Project Summary was developed
by EPA's Air and Energy Engineering
Research Laboratory, Research Triangle
Park, NC. to announce key findings of
the research project that is fully docu-
mented in a separate report of the same
title (see Project Report ordering infor-
mation at back).
Introduction
Radian Corporation has concluded a
literature search of available data on
woodstove emissions. In the computer
search of various libraries of information,
239 citations were identified through the
use of a key word listing which was
primarily for residential wood combustion
(RWC) emissions and their impact.
Approximately half of these were unique
citations; of that number, 53 were chosen
as applicable to this study. A computerized
abstract of the 53 citations and a key word
list are both included in the full report.
The citations and literature studies came
from all sectors of industry and govern-
ment. To date, no one agency or associa-
tion has coordinated all of the work which
has preceded this study. The result was
that the information was mostly piece-
meal as to its content, purpose, and
methods utilized.
The report: summarizes and gives
conclusions of this literature review;
summarizes the ranges of pollutants
emitted from RWC; reviews some of the
literature derived from ambient air stud-
ies; discusses the tracer compounds or
methods utilized to link ambient pollutants
to woodstove emissions; describes sam-
pling and analytical methods used to test
stoves; and discusses alternative design
approaches to residential wood burning
appliances.
Background
The use of wood for residential heating,
while aesthetically pleasing and econom-
ically attractive, may carry a potential for
adverse health effects to large segments
of the population. The impact of RWC on
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ambient PM emissions is especially no-
ticeable because the plume impacts the
ground very near the source. In addition,
the areas of highest RWC emission
density often coincide with the areas of
maximum population density, and most
of the RWC particulate emissions are
within the size range deposited within the
lungs. RWC emissions are relatively rich
in carcinogenic organics, toxic pollutants,
and respiratory irritants. For all of these
reasons, wood smoke is a problem that is
of growing public concern.
The chemical products formed during
wood combustion have recently been
shown to contain 17 priority pollutants,
14 carcinogenic compounds, and 6 toxic
or mucus coagulating agents which,
when considered in addition to toxic
gaseous emissions and respiratory irri-
tants, collectively represent a potential
health risk.
RWC emissions are becoming increas-
ingly important as a major contributor to
violations of current PM air quality stan-
dards and are implicated in issues related
to visibility reduction, odors, and public
health. New attention being focused on
the adoption of an Inhalable Particulate
(IP) National Ambient Air Quality Standard
(NAAQS) has also caused concern about
the RWC impact on 24-hour particulate
standard attainment. The continuing
economic pressures to expand the use of
wood and coal for residential heating, and
the limited regulatory pressures restric-
ting the use of wood, may cause additional
concern about the impact of RWC emis-
sions on public health, aesthetics, and
the future "livability" of many commun-
ities.
Summary
A literature search was conducted of
53 reports covering woodstove design,
operating conditions, emissions, testing
methods, and ambient air impacts. The
woodstoves studied, both controlled (cat-
alytic) and uncontrolled, varied in design
from simple to complex. The stoves
studied burned primarily cord wood. The
results of the tests were segregated
according to the type of wood utilized,
the percent moisture in the wood as
tested, the burn rate of the wood, the
stage of burning which was tested, and
the length of the test. In addition to the
operating conditions, the emissions were
qualified by the test method which was
performed, the firebox temperature, and
the stack temperature. Emission param-
eters studied included PM, CO, NO,, HC,
and POM, especially BaP. This report
includes ambient air impact surveys at
various locations in the U.S. Most ambient
studies were concerned with the PM and
HC impacts, but a few looked at relating
these impacts back to their sources.
The test methodologies used for both
the source testing of woodstoves and for
the ambient impact varied from study to
study. As a result, few conclusions or
trends could be drawn from the combined
studies. Conclusions and trends are seen
within each study, although the reader
must exercise caution as to the test
method and the test conditions utilized to
achieve these conclusions. An overview
of the testing methods and analytical
techniques is presented, with no con-
clusions or recommendations. Each study
selected a test method which best suited
its needs for the data. There is no standard
method of sampling and analysis for
woodstove emissions. ASTM is working
on such a standard. Also, there is no
standard set of conditions for the opera-
tion of the woodstoves, although guide-
lines are available.
Since the widespread use of wood-
stoves is a recent recurrence, the use of
controls on them is still somewhat rare.
The studies that evaluated control devices
(i.e., catalytic, secondary combustion,
and modified combustion) all reported
variable decreases in emissions relative
to standard stoves. No control devices
appeared to dramatically reduce emis-
sions under all conditions.
M. W. Hartman and G. D. Rives are with Radian Corporation, Research Triangle
Park, NC 27709.
Robert C. McCrillis is the EPA Project Officer (see below).
The complete report, entitled "Literature Review and Survey of Emissions from'
Residential Wood Combustion and Their Impact," (Order No. PB 85-197
820/AS; Cost: $13.00. subject to change) will be available only from:
National Technical Information Service
5285 Port Royal Road
Springfield, VA 22161
Telephone: 703-487-4650
The EPA Project Officer can be contacted at:
Air and Energy Engineering Research Laboratory
U.S. Environmental Protection Agency
Research Triangle Park, NC 27711
it U.S. GOVERNMENT PRINTING OFFICE: 1985-5594)16/27088
United States
Environmental Protection
Agency
Center for Environmental Research
Information
Cincinnati OH 45268
Official Business
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