REPORT ON REVISIONS TO
5TH EDITION AP-42
Section 1.10
Residential Wood Stoves
Prepared for:
Contract No. 68-D2-0160, Work Assignment 50
EPA Work Assignment Officer: Roy Huntley
Office of Air Quality Planning and Standards
Office of Air and Radiation
U. S. Environmental Protection Agency
Research Triangle Park, North Carolina 27711
Prepared by:
Eastern Research Group
Post Office Box 2010
Morrisville, North Carolina 27560
July 29, 1996
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Table of Contents
Page
1.0 INTRODUCTION 1-1
2.0 REVISIONS 2-1
2.1 General Text Changes 2-1
2.2 Paniculate Matter Less Than 10 Microns, PM-10 2-1
2.3 Carbon Monoxide, CO 2-1
2.4 Nitrogen Oxides, NOX 2-1
2.5 Sulfur Oxides, SOX 2-2
2.6 Total Organic Carbon, TOC 2-2
2.7 Organic Compounds 2-2
2.8 Polycyclic Aromatic Hydrocarbons, PAH 2-2
2.9 Trace Elements 2-3
2.10 Wood Heater Net Efficiencies 2-3
2.11 Greenhouse Gases 2-3
2.11.1 Carbon Dioxide, CO2 2-3
2.11.2 Methane, CH4 2-3
2.11.3 Nitrous Oxide, N2O 2-4
3.0 REFERENCES 3-1
4.0 REVISED SECTION 1.10 4-1
5.0 EMISSION FACTOR DOCUMENTATION, APRIL 1993 5-1
in
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1.0 INTRODUCTION
This report supplements the Emission Factor (EMF) Documentation for AP-42
Section 1.10, Residential Wood Stoves, dated April 1993. The EMF describes the source and
rationale for the material in the most recent updates to the 4th Edition, while this report provides
documentation for the updates written in both Supplements A and B to the 5th Edition.
Section 1.10 of AP-42 was reviewed by internal peer reviewers to identify technical
inadequacies and areas where state-of-the-art technological advances need to be incorporated.
Based on this review, text has been updated or modified to address any technical inadequacies or
provide clarification. Additionally, emission factors were checked for accuracy with information
in the EMF Document and new emission factors generated if recent test data were available.
If discrepancies were found when checking the factors with the information in the EMF
Document, the appropriate reference materials were then checked. In some cases, the factors
could not be verified with the information in the EMF Document or from the reference materials,
in which case the factors were not changed.
Four sections follow this introduction. Section 2 of this report documents the revisions
and the basis for the changes. Section 3 presents the references for the changes documented in
this report. Section 4 presents the revised AP-42 Section 1.10, and Section 5 contains the EMF
documentation dated April 1993.
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2.0 REVISIONS
This section documents the revisions made to Section 1.10 of the 5th Edition of AP-42.
2.1 General Text Changes
Text was added concerning emissions controls from information in the EMF Document.
Also, at the request of EPA, metric units were removed.
2.2 Particulate Matter Less Than 10 Microns. PM-10
The PM-10 emission factors were checked against information in the EMF Document and
the 9/91 version of AP-42 and no changes were required.
2.3 Carbon Monoxide. CO
The CO emission factors were checked against information in the EMF Document and
the 9/91 version of AP-42 and no changes were necessary.
2.4 Nitrogen Oxides. MX
The NOX emission factors were checked against information in the EMF Document and
the 9/91 version of AP-42 and no changes were required.
2.5 Sulfur Oxides. SO::
The SOX emission factors were checked against information in the EMF Document and
no change were necessary.
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2.6 Total Organic Carbon. TOC
EPA provided new TOC emissions data for conventional, noncatalytic, and catalytic
wood stoves.1'2 The changes are shown in the following table:
Pollute
nt
TOC
Methan
e
Methan
e
Emission
Factor
Rating
E
E
E
Existing Emission Factors, Ib/ton
Convention
al
48.6
4.8
43.8
Noncatalyt
ic
ND
ND
ND
Catalytic
24.2
8.6
15.6
Emission
Factor
Rating
C
C
C
Emission Factors, Ib/ton
Conventional
83
30
53
Noncatalytic
28
16
12
Cataly
tic
26.6
11.6
15
2.7 Organic Compounds
These emission factors were checked with information in the EMF Document and no
changes were required.
2.8 Polycyclic Aromatic Hydrocarbons. PAH
The PAH emission factors were checked against information in the EMF Document. The
only change was with the Phenanthrene emission factor for catalytic stoves which changed from
0.48 Ib/ton to 0.048 Ib/ton (typographical error).
2.9 Trace Elements
These emission factors were checked against information in the EMF Document and no
changes were necessary.
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2.10 Wood Heater Net Efficiencies
The efficiencies were checked against information in the EMF Document and no changes
were necessary.
2.11 Greenhouse Gases
2.11.1 Carbon Dioxide, CO2
The CO2 factors remain the same as in the 1/95 version of AP-42.
2.11.2 Methane, CH4
Data located in addition to EMF documentation confirms the highly variable nature of
methane emissions from residential wood stoves.1'2 The range of emissions values shown in
Table 3-14 confirm the order of magnitude of the current emission factors only. The CH4
emissions factors therefore remain the same as in the 1/95 version of AP-42.
Table 1. CH4 Emission Factors for Residential Wood Stoves for AP-42 Section 1.10
(Ib CH4/ton wood)
Process
Domestic furnaces
Domestic - Slow combustion
Domestic - Small stoves
EF Rating
E
E
E
EF
0.3a
la
18b
AP-42 EF
None
4.8
4.8
AP-42 Rating
E
E
a Reference 1.
b Reference 2.
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2.11.3 Nitrous Oxide, N2O
No N9O emissions data was found.
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3.0 REFERENCES
1. Letter and Attachments to Susan Stamey-Hall, Radian Corporation from
Robert C. McCrillis, U.S. Environmental Protection Agency, concerning VOC emissions
from Wood Stoves, May 8, 1995.
2. Jaasma, D.R., Stern, C.H., and M. Champion, Field Performance of Wood Burning
Stoves in Crested Butte During the 1991-1992 Heating Season, EPA-600/R-94-061, U.S.
Environmental Protection Agency, Research Triangle Park, April 1994.
3. Ortech Corporation, Inventory Methods Manual For Estimating Canadian Emissions Of
Greenhouse Gases, Prepared for Environment Canada, 1994.
4. Rosland, Audun, Greenhouse Gas Emissions In Norway: Inventories And Estimation
Methods, Oslo: Ministry of Environment, 1993.
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4.0 REVISED SECTION 1.10
This section contains the revised Section 1.10, Residential Wood Stoves. The electronic
version can be located on the EPA TTN at http://134.67.104.12/html/chief/fsnpub.htm.
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5.0 EMIS SIGN FACTOR DOCUMENTATION, APRIL 1993
This section contains the Emission Factor Documentation for AP-42 Section 1.10,
Residential Wood Stoves, dated April 1993. The electronic version can be located on the EPA
TTN at http://134.67.104.12/html/chief/fbgdocs.htm. The zipped file on the TTN contains this
(1996) background report as well as the 1993 Emission Factor Documentation.
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EMISSION FACTOR DOCUMENTATION FOR
AP-42 SECTION 1.10,
RESIDENTIAL WOOD STOVES
Prepared by:
E.H. Pechan & Associates, Inc.
Rancho Cordova, CA 95742
EPA Contract No. 68-DO-0120
EPA Work Assignment Officer: Michael Hamlin
Office of Air Quality Planning and Standards
Office of Air And Radiation
U.S. Environmental Protection Agency
Research Triangle Park, NC 27711
April 1993
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Disclaimer
This report has been reviewed by the Office of Air Quality Planning and Standards, U.S. Environmental Protection
Agency, and approved for publication. Mention of trade names or commercial products does not constitute
endorsement or recommendation for use.
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TABLE OF CONTENTS
Page
CHAPTER 1. INTRODUCTION 1-1
CHAPTER 2. SOURCE DESCRIPTION 2-1
2.1 PROCESS DESCRIPTION 2-3
2.2 EMISSIONS 2-4
2.3 CONTROL TECHNOLOGY 2-5
REFERENCES 2-6
CHAPTER 3. GENERAL EMISSION DATA REVIEW AND ANALYSIS PROCEDURE 3-1
3.1 DATA SEARCH AND SCREENING 3-1
3.2 EMISSION DATA QUALITY RATING SYSTEM 3-1
3.3 EMISSION FACTOR QUALITY RATING SYSTEM 3-2
REFERENCES 3-4
CHAPTER 4. EMISSION FACTOR DEVELOPMENT 4-1
4.1 REVIEW OF EXISTING DATA SETS 4-1
4.2 REVIEW OF NEW DATA SETS 4-2
4.2.1 Reference 7 - Wood Stoves 4-2
4.2.2 Reference 8 - Exempt Pellet Stoves 4-2
4.2.3 References 9 and 10 - Preliminary Data on Wood Stoves 4-4
4.2.4 References 11, 13, 13, 14, 15 - Masonry Heaters 4-4
4.3 EMISSION FACTOR METHODOLOGY 4-6
4.3.1 Criteria Pollutant Emission Factor Development 4-6
4.3.1.1 PM Emission Factor Development 4-7
4.3.2 Non-Criteria Pollutant Emission Factor Development 4-8
4.4 EMISSION FACTOR RESULTS 4-8
REFERENCES 4-9
CHAPTER 5. AP-42 SECTION 1.10: RESIDENTIAL WOOD STOVES 5-1
APPENDIX A. SAMPLE CALCULATIONS AND EPA METHOD 5G CORRELATION EQUATIONS .. A-l
APPENDIX B. MARKED-UP PREVIOUS AP-42 SECTION 1.10 B-l
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1. INTRODUCTION
Emission factors are the basis for emission estimates made by State and local air pollution
control agencies, industry and manufacturers of both pollution-generating and controlling
equipment. Beginning in 1972, the U.S. Environmental Protection Agency (EPA) has published
"Compilation of Air Pollutant Emission Factors" (AP-42) to make emission factors available to
regulators and industry. An emission factor relates the quantity (weight) of a pollutant to a unit
of activity from the source. Uses of AP-42 emission factors include:
! Estimates of area-wide emissions;
! Estimates for a specific facility emissions; and
! Evaluation of emissions relative to ambient air quality.
This emission factor document provides background information and analysis used to
review and revise emission factors located in AP-42 Chapter 1, Section 1.10: Residential Wood
Stoves. The current revision updates section 1.10 to include any new data for criteria and non-
criteria pollutants.
This report contains five chapters, including the introduction (Chapter 1). Chapter 2,
describes the types of wood stoves, and characterizes wood stove combustion emissions and
controls. Chapter 3 describes the procedure used to rank emissions data and emission factors.
Chapter 4 explains the development of new emission factors for carbon monoxide (CO),
particulate matter (PM), and hazardous air pollutants (HAPs), including an explanation of the
data base used to calculate emission factors. Chapter 5 contains the actual, revised AP-42
section for residential wood stoves. Appendix A includes sample calculations and EPA Method
5G correlation equations. Appendix B contains the current AP-42 section with hand-written
remarks depicting the changes which will be made as part of this revision.
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2. SOURCE DESCRIPTION
Residential wood combustion (RWC) is an emission category which primarily consists of
emissions from wood stoves and fireplaces. In some airsheds RWC emissions can be the main
source of air pollution and cause violations of the National Ambient Air Quality Standard
(NAAQS) for PM with an aerodynamic diameter of 10 micrometers or less (PM-10).
Regulations to control emissions from wood stoves were first undertaken by EPA in 1988
with promulgation of the New Source Performance Standards (NSPS)1. NSPS provides emission
limits on wood stoves manufactured and/or sold in the U.S. A phase-in of the emission limits
allowed time for the wood stove industry to develop cleaner and more efficient devices.
Emission limits were applied to two broad categories of wood stoves: catalytic and noncatalytic.
Catalytic wood stoves utilize a catalytic combustor (see section 2.4 of this report for an
explanation) and noncatalytic stoves include all other wood stoves. Other wood heaters which
are exempt from NSPS have been developed and are capable of achieving reduced emissions.
These exempt devices include some models of pellet stoves (exempt due to an air-to-fuel ratio
greater than 35-to-l) and masonry heaters (exempt due to a mass weight greater than 800 kg).
Table 2-1 summarizes the 1988 NSPS.
Wood stoves are a popular source of primary and secondary heating for residences. A
1988 survey conducted for the Consumer Product Safety Commission (CPSC) estimates that
there are 9.7 million wood and coal stoves in use in the U.S.2 About 95 percent (8.9 million
stoves) burn wood exclusively. The survey also reports that wood and coal stoves are the most
intensively used type of space heater in terms
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TABLE 2-1. SUMMARY OF THE NEW SOURCE PERFORMANCE STANDARDS
FOR RESIDENTIAL WOOD STOVES
WOOD STOVE TYPE
Catalytic NonCatalytic
Phase I
Emission Limit (g/hr)
Effective date-for manufacture
Effective date-for sales
Phase II
Emission Limit (g/hr)
Effective date-for manufacture
Effective date-for sales
5.5
7/1/88
7/1/90
4.1
7/1/90
7/1/91
8.5
7/1/88
7/1/90
7.5
7/1/90
7/1/92
of average usage per heater (2100 hours) and total average annual usage (20 billion hours).
Based on known variations in construction, combustion and emissions characteristics,
there are generally considered to be at least four categories of wood stoves: (1) Catalytic, which
use catalytic combustion technology; (2) Noncatalytic, which use noncatalytic emission reduction
technology (e.g., secondary combustion chambers); (3) Pellet, which burn densified biomass
pellet fuel in a specialized firebox; and (4) Conventional, which includes all other types of wood
stoves not included in the other three categories, and which do not use emission reduction
technology. Another type of wood burning device which is used as both a primary and secondary
heat source in residences is the masonry heater.
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2.1 PROCESS DESCRIPTION
A wood stove is an enclosed wood heater which controls burning or burn time by
restricting the amount of air that can be used for combustion. Controlling the amount of air a fire
needs for complete combustion controls the amount of the fuel converted to heat, while the
remainder is primarily emitted in the form of CO, PM and condensable organics.
A pellet stove uses recycled biomass fuel, usually wood, which is compressed and shaped
into pellet form, about one inch long. The pellets are loaded into a hopper and fed to the fire by
use of an auger which is run by an electric motor. The rate of combustion is controlled by the
amount of fuel fed into the firebox. This compares to the wood stove which uses air flow as a
method of control. The pellet stoves, therefore, burn cleaner and are more efficient than wood
stoves. Disadvantages of the pellet stove compared to the wood stove are that regular cleaning is
needed to prevent build up of dust and ash in air passages which can greatly affect stove
efficiency, and in the event of a power failure the auger stops and the stove cannot operate.
Masonry heaters are large, enclosed chambers made of masonry products or a
combination of masonry products and ceramic materials. These devices are exempt from the
1988 NSPS due to their weight (i.e., greater than 800 kg). Masonry heaters are gaining
popularity as a cleaner burning and heat efficient form of primary and supplemental heat, relative
to some other types of wood heaters. In a masonry heater, a complete charge of wood is burned
in a relatively short period of time. The use of masonry materials promotes heat transfer; thus,
radiant heat from the heater warms the surrounding area for many hours after the fire has burned
out.
Net or overall efficiency is the product of combustion efficiency multiplied by heat
transfer efficiency. Wood heater efficiency is an important parameter used, along with emission
factors and percent degradation, when calculating PM-10 emission reduction credits.3 Table 2-1
provides a summary of net efficiencies, by wood heater type. These efficiencies were calculated
entirely from field test data. Percent degradation is related to the loss in effectiveness of a wood
stove control device or catalyst over a period of operation. Control degradation for any stove,
including noncatalytic wood stoves, may also occur as a result of deteriorated seals and gaskets,
misaligned baffles and bypass mechanisms, broken refractories, or other damaged functional
2-3
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components. The increase in emissions which can result from control degradation has not been
quantified. However, recent wood stove testing in Colorado and Oregon should produce results
which allow estimation of emissions as a function of stove age.
TABLE 2-2. SUMMARY OF WOOD HEATER NET EFFICIENCIES
Wood Heater Type
Conventional
Noncatalytic
Pellet - Certified
- Exempt
Catalytic
Masonry Heater
Efficiency %
Range Average
41.7-63.1 53
66.2-72.6 68
57.6-75.2 67
33.4-70.5 55
63.0-78.4 67
54-65 58
6
3
5
5
9
4
Reference
4
4,5,6
7
8
4,9
10
2.2 EMISSIONS
Wood stove emissions are by-products of incomplete combustion, and include paniculate
matter (mainly PM-10), (CO), oxides of sulfur (SOX) and of nitrogen (NOX), volatile organic
compounds (VOCs), and HAPs including polycyclic organic material (POM). POM is a class of
compounds which contains a sub-set known as Polycyclic Aromatic Hydrocarbons (PAHs). An
important fuel characteristic which contributes to PM-10 emissions from wood stoves is moisture
content. Other important characteristics which affect emissions are burn rate and flame intensity.
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One estimate indicates that the annual emissions from wood stoves in the U.S. are 0.8
tons of PM-10, 4.7 million tons of CO, and 1.0 million tons of VOCs.a The effect of these
emissions is worsened in two ways. First, by adverse meteorology during the wood burning
season (i.e., wintertime temperature inversions). Second, large regional variations in proportions
of households actively using wood stoves (e.g., 21.4% of the households in the Mountain region
versus 8.6% of the households in the Middle Atlantic region) also affect emissions.
2.3 CONTROL TECHNOLOGY
In order to decrease PM and CO emissions from wood stoves, combustion efficiency
must increase. Increasing burn rate and flame intensity results in better efficiency. Both catalytic
and noncatalytic control techniques increase efficiency and decrease emissions.3 Catalytic
combustors reduce emissions by using a ceramic catalyst coated with a noble metal (e.g.,
palladium or platinum) which allows organics and other combustibles to burn at temperatures
much lower than required in a noncatalytic firebox. Older, noncatalytic wood stoves reduce
emissions by directing unburned hydrocarbons (HCs) and CO into a secondary chamber, where
mixing with fresh, preheated makeup air enhances further combustion. Current noncatalytic
NSPS wood stove inject fresh secondary air into the top are of the primary combustion chamber,
allowing ignition of the unburned HCs. Multiple air channels, some with their own controls,
coupled with baffles which trap and retain heat in the top of the firebox, facilitate this
combustion.
a These values are based on the 1985 National Acid Precipitation Assessment Program (NAPAP)
estimates for RWC emissions, with the following assumptions based on discussions with RWC experts:
66 percent of the total RWC emissions are from wood stoves, 100 percent of the total suspended
particulate emissions are PM-10, and a 5 percent increase in all RWC pollutants since 1985 due to
growth which exceeds reductions from change-over to new technology stoves.
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REFERENCES FOR CHAPTER 2
1. "Standard of Performance for New Stationary Sources: New Residential Wood Heaters,"
Federal Register, Volume 53, Number 38, Section 40 CFR, Part 60, February 1988.
2. Zamula, W.W., "Room Heating Equipment Exposure Survey," Final Report, U.S.
Consumer Product Safety Commission, Directorate for Economic Analysis, OMB
Control No. 3041-0083, Washington, DC, March 1989.
3. "Guidance Document for Residential Wood Combustion Emission Control Measures,"
EPA-450/2-89-015, Office of Air Quality Planning and Standards, U.S. Environmental
Protection Agency, Research Triangle Park, NC, September 1989; including Errata Sheet,
June 1991.
4. Barnett, S.G. and R.D. Bighouse, "In-Home Demonstrations of the Reduction of
Woodstove Emissions from the use of Densified Logs," Oregon Department of Energy
and U.S. Environmental Protection Agency, July 1992.
5. Dernbach, S., "Woodstove Field Performance In Klamath Falls, OR," Wood Heating
Alliance, Washington, DC, April 1990.
6. Barnett, S.G., "In-Home Evaluation of Emission Characteristics of EPA-Certified High-
Tech Non-Catalytic Woodstoves in Klamath Falls, OR, 1990," prepared for the Canada
Center for Mineral and Energy Technology, Energy, Mines and Resources, Canada, DSS
File No. 145Q, 23440-9-9230, June 1, 1990.
7. Barnett, S.G., and R.B. Roholt, "In-home Performance of Certified Pellet Stoves In
Medford And Klamath Falls, OR," U.S. Department of Energy Report No. PS407-02,
July 1990.
8. Barnett, S.G. and P.G. Fields, "In-Home Performance of Exempt Pellet Stoves in
Medford, Oregon," U.S. Department of Energy, Oregon Department of Energy,
Tennessee Valley Authority, and Oregon Department of Environmental Quality, July
1991.
9. Barnett, S.G., "Field Performance of Advanced Technology Woodstoves In Glens Falls,
N.Y. 1988-1989," Vol. 1, New York State Energy Research And Development Authority,
Albany, NY, October 1989.
10. Barnett, S.G., "Summary Report of the In-Home Emissions and Efficiency Performance
of Five Commercially Available Masonry Heaters," the Masonry Heater Association,
May 1992.
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3. GENERAL EMISSION DATA REVIEW AND ANALYSIS PROCEDURE
3.1 DATA SEARCH AND SCREENING
The first step in updating the wood stove emission factor data base was to contact experts
in the field of residential wood combustion in order to determine if new test data were available
since the last AP-42 update.1'2'3 A recent update of AP-42 emission factors for wood stoves
provides a current data base on which to add new data.
3.2 EMISSION DATA QUALITY RATING SYSTEM
The quality and quantity of the new test data were ranked pursuant to EPA guidance and
assigned a quality ranking based on the following criteria:4'5
A - Tests performed using sound methodology and reported in enough detail to provide
adequate validation. These tests may not be EPA reference method tests, although
such reference methods are preferred and to be used as a guide.
B - Tests performed using sound methodology, but lacking enough detail to provide
adequate validation.
C - Tests performed using an unproven or new methodology, or are lacking a significant
amount of background data.
D - Tests performed using a generally unacceptable method, but the method may provide
an order-of-magnitude value for the source.
Guidelines to evaluate the data for sound methodology and adequate detail were:
! Source operation. The source was operating within typical parameters during the
test and the parameters are well documented.
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! Sampling procedures. If actual procedures deviated from standard methods
during the test, the deviations are well documented and evaluated to determine
their influence on the test results.
! Sampling and process data. If a large spread between test results cannot be
explained by information contained in the test report, then the data are suspect and
are given a lower rating.
! Analysis and calculations. The test reports should contain original raw data
sheets. Nomenclature and equations used are compared with those specified by
EPA to establish equivalency. The depth of calculation review is determined by
the reviewers' confidence in the ability and conscientiousness of the tester.
Interpreted ability is, in turn, based on factors such as consistency of results and
completeness of other areas of the test report.
3.3 EMISSION FACTOR QUALITY RATING SYSTEM
After evaluating emissions data and calculating new emission factors, a quality rating of
the emission factor was determined based on the following criteria:
A - Excellent: The emission factor was developed from only A-rated source data, and
taken from many randomly chosen facilities. The source category is specific enough to
minimize variability within the source population.
B - Above average: The emission factor was developed from only A-rated source data,
but it is not clear if the facilities tested represent a random sample of the population. As
with the A-rated emission factor, the source category is specific enough to minimize
variability within the source population.
C - Average: The emission factor was developed from only A- and B-rated source data,
and from a reasonable number of facilities. It is not clear if the facilities tested represent
a random sample of the population. As with the A-rated emission factor, the source
category is specific enough to minimize variability within the source population.
D - Below average: The emission factor was developed from only A- and B-rated source
data, and from a small number of facilities. There may be reason to suspect that these
facilities do not represent a random sample of the population. Also, there may be
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evidence of variability with the source population. Any limitations on the use of this
emission factor are noted in the emission factor table.
E - Poor: The emission factor was developed from C- and D-rated source data. There
may be reason to suspect that the facilities tested do not represent a random sample of the
population. Also, there may be evidence of variability with the source population. Any
limitations on the use of this emission factor are noted in the emission factor table.
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REFERENCES FOR CHAPTER 3
1. Verbal Communication from Robert C. McCrillis, U.S. Environmental Protection
Agency, Research Triangle Park, NC, to Paula G. Fields and George E. Weant, E.H.
Pechan and Associates, Inc., Rancho Cordova, CA, April-May, 1992.
2. Written Communication from Stockton G. Barnett, OMNI Environmental Services, Inc.
Beaverton, OR, to Paula G. Fields, E.H. Pechan and Associates, Inc., Rancho Cordova,
CA, May 18, 1992.
3. Written Communication from Paul Tiegs, OMNI Environmental Services, Inc.,
Beaverton, OR, to George E. Weant, E.H. Pechan and Associates, Inc., Durham, NC,
March 26, 1992.
4. Technical Procedures for Developing AP-42 Emission Factors and Preparing AP-42
Sections, Office of Air Quality Planning and Standards, U.S. Environmental Protection
Agency, Research Triangle Park, NC, March 1992.
5. "Clarification to AP-42 Procedures Document," Memo from J. Southerland, Emission
Factor and Methodologies Section, U.S. Environmental Protection Agency, Research
Triangle Park, NC, April 1992.
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4. EMISSION FACTOR DEVELOPMENT
This chapter describes the test data and methodology used to review and revise the
emission factors for residential wood stoves. This chapter discusses existing wood stove data
sets and introduces new test data for HAPs from wood stoves and pellet stoves. The chapter ends
with a discussion of emission factor data base and calculations.
4.1 REVIEW OF EXISTING DATA SETS
The AP-42 emission factors for residential wood stoves were last reviewed and revised in
September 1991, and subsequently published as part of AP-42, Supplement D. The data base of
emissions testing results was edited to include the most recent test data available during the 1991
revisions. The existing criteria pollutant emission factors and their ratings were used as a basis
for the current update. During the current revision to AP-42 Chapter 1, Section 1.10, the 1991
emission factor documentation was reviewed to determine if it contained any non-criteria
emissions data. As a result, some HAP data (i.e., PAH) for wood stoves were obtained.1A3A5
These data, which included emission rates and/or factors for PAH and elemental HAPs, were all
rated "D." Also, "B" rated CO2 data were obtained for certified pellet stoves.6
It should be noted that during the review of the existing data base, the PM emission
factors were recalculated due to a change in the correlation equations which adjust the field-
collected data to equivalent EPA method 5G values. (See section 4.3.1.1 for details of these
calculations).
4.2 REVIEW OF NEW DATA SETS
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One report each on wood stove testing and exempt pellet stove testing were obtained.7'8
Preliminary data from wood stoves tested in Crested Butte, Colorado and Klamath Falls, Oregon
were obtained.9'10 Five test reports on masonry heaters were obtained. n'12'13'14'15
4.2.1 Reference 7 - Wood Stoves
This report contained wood stove test data for PM, speciated organic compounds, and
HAPs taken from 12 tests on a conventional stove and two tests on a catalytic stove. These tests
were conducted in Boise, Idaho as part of the Integrated Air Cancer Project (IACP) sponsored by
EPA and were deliberately complementary to another IACP test series performed on a
noncatalytic stove.2 A wood stove dilution sampler (WS2) was used to collect particulate
samples and a modified ambient sampler was used to collect organic compound samples. The
data from this test series were variable between test runs (i.e., this test was intended to examine
wood stove emissions based on variability of wood type, altitude and burn rate). PM data from
this reference were not included in emission factor development due to the inability to relate the
particulate emissions to equivalent EPA Method 5H emissions. Organic and PAH emissions
data were used in emission factor development; each data set was given a rating of "D." Organic
compound data from Reference 2 were not used for emission factor development, as many
problems were encountered during the testing as documented in the report.
4.2.2 Reference 8 - Exempt Pellet Stoves
Reference 8 reported PM, CO, CO2 and PAH emissions from six exempt pellet stoves
under in-home burning conditions in Medford, Oregon during 1991. Exempt pellet stoves are
stoves which are excluded from the emissions certification process because they operate at an air-
to-fuel ratio in excess of 35-to-l. The PM and CO data were rated "A." The CO2 data were rated
"B." The PAH were rated "D" based on the testing method. A summary of the PM, CO and CO2
pellet stove data is shown in Table 4-1.
4-2
-------
TABLE 4-1. SUMMARY OF EMISSIONS DATA FROM EXEMPT PELLET STOVES3
Sample Dates (1991)
Total Burn Time
(his)
Avg. Burn Rate:
dry kg/hr
Avg. PM Emissions:
g/kg
Avg. CO Emissions:
g/kg
Avg. CO2 Emissions:
g/kg
HOUSE
P01 P02 P03
1/25- 1/28- 1/26-
2/21 13/1 2/21
587 533 578
0.68 0.84 0.48
1.35 3.27 6.33
8.23 20.52 38.76
1,827.3 1,895.4 1,838.4
IDENTIFICATION
P04 P05
1/24- 1/25-
2/19 2/19
527 591
0.49 0.54
2.81 5.69
16.33 33.73
1,856.0 1,876.3
P06 AVERAGE DATA
RATING
1/29-
2/21
464
0.47 0.58
4.52 3.99 A
38.96 26.09 A
1,719.8 1,835.6 B
-------
4.2.3 References 9 and 10 - Preliminary Data on Wood Stoves
During the winter of 1991-1992, two separate series of in-home emissions tests were
conducted on wood stoves in Crested Butte (two noncatalytic Phase II stoves, six catalytic Phase
I and two catalytic Phase II stoves) and Klamath Falls (four conventional stoves, three
noncatalytic Phase II stoves and two catalytic Phase II stoves). The results of these tests are
important in that these stoves have been tested in prior years (excluding the Klamath Falls
conventional wood stoves) and the results should provide some insight into the effect of stove
degradation on emissions. Degradation mainly affects catalytic components. However, over
time, warpage of other internal parts can cause leaks which contribute to increased emissions.
Results of these two tests are summarized in Table 4-2, even though the data cannot be included
in emission factor development pending evaluation of the test reports. A preferred approach for
tracking degradation might be to extract from the existing data base any emissions data for stoves
with test results from multiple years, and add in the most recent year's data to form a separate
"degradation" data base. In fact, work has already begun to develop this type of data base.
4.2.4 References 11. 13. 13. 14. 15 - Masonry Heaters
References 11 through 15 reported emissions from five types of masonry heaters under
in-home burning conditions. All five references reported PM, CO and CO2 emissions. These
data were rated "A." A summary of the test data from all five test series is shown in Table 4-3.
Reference 11 also reported emissions for a "Russian" style masonry heater which was
constructed by a mason from a plan that was later changed. Emissions from this unit were not
included in the emission factor development since this unit is not commercially available and is
probably not representative of the general masonry heater population in terms of construction or
emissions.
4-4
-------
TABLE 4-2. SUMMARY OF "PRELIMINARY" EMISSIONS DATA FROM WOOD STOVES IN
CRESTED BUTTE AND KLAMATH FALLS
EPA Certification:0
Cat-Pi
Sample Start Dates 2/1 1/92
Total Burn Time (hrs) 2450
Crested Butte Test Series"
Sampler = VPI
Non-Cat-PII
2/6/92
258
Cat-PII
Conv
2/10/92 1/8/92
332 630
Klamath Falls Test Series'3
Sampler = AWES
Non-Cat-PII
1/7/92
483
Cat-PII
1/7/92
335
Avg. Burn Rate
Dry kg/hr
Avg. PM Emissions:
0.80
0.80
1.13
1.48
1.30
1.37
g/kg
g/hr
Avg. CO Emissions:
g/kg
g/hr
VOC Emissions
g/kg
g/hr
16.33 12.82
13.05 10.22
80 105
63 80
NA NA
9.91 23.66
11.15 34.95
57 161.21
66 202.54
NA
19.74
24.80
4.26
5.54
50.35
62.75
13.30
16.61
8.24
11.28
57.35
76.86
14.14
19.13
a. Wood burned includes apple, oak, pine and spruce.
b. Wood burned includes logdepole pine, douglas fir and juniper.
c. Cat-Pi means Catalytic, Phase I certified; N-Cat-PII means Noncatalytic, Phase II certified; Cat-PII means catalytic, Phase II certified; Conv means
conventional.
NA = No data available.
-------
TABLE 4-3. SUMMARY OF NEW IN-HOME EMISSIONS DATA
FOR MASONRY HEATERS1115
Sample Dates 1991-1992
Fuels Douglas Fir, Alder
Average Fuel Moisture 19%
Total Burn Time 135.1 hours
Total Burn Cycles 41
Average Burn Rate 4.73 dry kg/hr
Average Emissions:3
PM 2.8 g/kg
CO 74.5 g/kg
CO2 1,924.7 g/kg
a. These data were collected using an AWES unit, and have been converted to M5H equivalent values. See
section 4.3.1.1 of this report for an explanation of the conversion calculations, and Appendix A for a
sample calculation.
4.3 EMISSION FACTOR METHODOLOGY
A Lotus 1-2-3™ spreadsheet was used to compile PM and CO emissions data and calculate
emission factors as part of the 1991 revision to the AP-42 section on residential wood stoves.
The 1991 spreadsheets were updated during the current revision to include new correlation
equations used to calculate equivalent EPA Method 5H values for PM from field-test data. (See
section 4.3.1.1 for details of these calculations). New spreadsheets were developed to calculate
PM, CO and speciated organic compound emission factors from new references. Also, new
spreadsheets were developed to calculate emission factors for noncriteria pollutants (i.e., CO2
and PAH).
4.3.1 Criteria Pollutant Emission Factor Development
Emission factors for NOX (rated "E"), SOX (rated "B"), were not changed from the 1991
emission factors. Emission factors for CO and PM were revised using existing emission factors
(rated "B") and new data (rated "A") resulting in new composite CO and PM emission factors,
4-7
-------
both rated "B." Emission factors for total organic compounds (TOC) were revised and rated "E"
based on limited data showing high variability.
4.3.1.1 PM Emission Factor Development. The EPA Method 5H (M5H) is the basis for
New Source Performance Standards (NSPS) for wood stoves, and was used as the reference
method for evaluating wood stove, pellet stove and masonry heater particulate emission test
results. The new PM test data for wood stoves (Klamath Falls), exempt pellet stoves and
masonry heaters were collected using an Automated Wood Stove Emissions Sampler (AWES).
Other new PM test data for wood stoves (Crested Butte) were collected using a field sampler
developed at Virginia Polytechnic Institute (VPI). The results of these two test procedures are
related to the EPA Method 5G (M5G) by the following equations:
,0.9289
M5G = 0.8635 x (AWES)(
M5G = 0.6748 x (KPT)1'007
After the AWES and VPI data were converted to equivalent M5G values, the following equation
was used to convert the M5G values to equivalent M5H values:
M5H = 1.619 x (M5G)0'905
These equations were developed by performing a linear regression on data taken from
simultaneous AWES-M5G, VPI-M5G tests.16'17'18'19 A sample calculation using these conversion
equations along with the graphical results of the linear regression of AWES-M5G and VPI-M5G
data are shown in Appendix A. It should be noted that the AWES-M5G and VPI-M5G equations
have recently been revised and the new equations are used in emission factor development for the
first time in this revision. Also, all previously collected VPI and AWES data have been revised
using these new correlation equations.
4-8
-------
4.3.2 Non-Criteria Pollutant Emission Factor Development
The "D" rated PAH data from references 1 through 5, 7 and 8 were compiled, resulting in
"E" rated emission factors for wood stoves and exempt pellet stoves. The "D" rated data for trace
elements from references 4 and 7 were compiled resulting in "E" rated emission factors for wood
stoves. The "D" rated speciated organic data from reference 7 resulted in "E" rated emission
factors for wood stoves.
Emission factors for CO2 from pellet stoves and masonry heaters were calculated using
the ratio of percent CO2 to percent CO. This method was used since only the values of percent
CO2 were obtained from the test data. These data (rated "B") produced "C" rated emission
factors.
4.4 EMISSION FACTOR RESULTS
A complete set of emission factors, which includes new and unrevised factors, is found in
Chapter 5 as part of the revised AP-42 Chapter 1, Section 1.10.
4-9
-------
REFERENCES FOR CHAPTER 4
1. Cottone, L.E., and E. Mesner, "Test Method Evaluations and Emissions Testing for
Rating Wood Stoves," EPA-600/2-86-100, U.S. Environmental Protection Agency,
Research Triangle Park, NC, October 1986.
2. Leese, K.E., and S.M. Harkins,"Effects of Burn Rate, Wood Species, Moisture Content,
and Weight of Wood Loaded on Wood Stove Emissions," EPA-600/2-89-025, U.S.
Environmental Protection Agency, Research Triangle Park, NC, May 1989.
3. Allen, J.M., et al., "Study of the Effectiveness of a Catalytic Combustion Device on a
Wood Burning Appliance," EPA-600/7-84-046, U.S. Environmental Protection Agency,
Research Triangle Park, NC, March 1984.
4. "Residential Wood Heater Test Report," Phase II Testing, Vol. 1, TV A, Div. of Energy,
Conservation and Rates, Chattanooga, TN, August 1983.
5. Truesdale, R.S., and J.G. Cleland, "Residential Stove Emissions from Coal and Other
Alternative Fuels Combustion," in Papers Presented at the Specialty Conference on
Residential Wood and Coal Combustion, Louisville, KY, March 1982.
6. Barnett, S.G. and R.B. Roholt, "In-Home Performance of Certified Pellet Stoves in
Medford and Klamath Falls, Oregon," U.S. Department of Energy Report No. PS407-02,
July 1990.
7. Burnet, P.O., et al., "Effects of Appliance Type and Operating Variables on Woodstove
Emissions," Volume I, Report and Appendices A-C, EPA-600/2-90-001a, U.S.
Environmental Protection Agency, Air and Energy Engineering Research Laboratory,
Research Triangle Park, NC, January 1990.
8. Barnett, S.G., and P.G. Fields, "In-Home Performance of Exempt Pellet Stoves in
Medford, Oregon," OMNI Environmental Services, Inc., Beaverton, OR, July 1991.
9. Written communication from Robert C. McCrillis, U.S. Environmental Protection
Agency, Research Triangle Park, NC, to Paula G. Fields, E.H. Pechan and Associates,
Inc., Rancho Cordova, CA, May 18, 1992.
REFERENCES FOR CHAPTER 4 (Continued)
4-10
-------
10. Written communication from Stockton G. Barnett, OMNI Environmental Services, Inc.,
Beaverton, OR, to Paula G. Fields, E.H. Pechan and Associates, Inc., Rancho Cordova,
CA,May 18, 1992.
11. Barnett, S.G., "In-Home Evaluation of Emissions From Masonry Fireplaces and Heaters,"
OMNI Environmental Services, Inc., Beaverton, OR, September 1991.
12. Barnett, S.G., "In-Home Evaluation of Emissions From a Grundofen Masonry Heater,"
OMNI Environmental Services, Inc., Beaverton, OR, January 1992.
13. Barnett, S.G., "In-Home Evaluation of Emissions From a Tulikivi KTU 2100 Masonry
Heater," OMNI Environmental Services, Inc., Beaverton, OR, March 1992.
14. Barnett, S.G., "In-Home Evaluation of Emissions From a Royal Crown 2000 Masonry
Heater," OMNI Environmental Services, Inc., Beaverton, OR, March 1992.
15. Barnett, S.G., "In-Home Evaluation of Emissions From a Biofire 4x3 Masonry Heater,"
OMNI Environmental Services, Inc., Beaverton, OR, March 1992.
16. Barnett, S.G., "Relationship of the AWES to EPA Methods 5H and 5G," OMNI
Environmental Services, Inc., Beaverton, OR, December 1991.
17. Burnet, P.G., "The Northeast Cooperative Woodstove Study," Volume 1, EPA-600/7-87-
026a, U.S. Environmental Protection Agency, Research Triangle Park, NC, November
1987.
18. McCrillis, R.C., "Long-Term Wood Stove Catalysts Performance Under Simulated
Residential Use," EPA-600/0-87-157, U.S. Environmental Protection Agency, Research
Triangle Park, NC, June 1987.
19. Memorandum from P.R. Westlin, U.S. Environmental Protection agency, Research
Triangle Park, NC, to J. Kowalczyk, Oregon Department of Environmental Quality,
Portland, Oregon, July 13, 1986.
4-11
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5. AP-42 SECTION 1.10: RESIDENTIAL WOOD STOVES
The revision to Section 1.10 of AP-42 is presented in the following pages as it would
appear in the AP-42 document.
5-1
-------
1.10 RESIDENTIAL WOOD STOVES
1.10.1 General1'3
Wood stoves are commonly used in residences as space heaters. They are used both as the
primary source of residential heat and to supplement conventional heating systems.
Five different categories should be considered when estimating emissions from wood burning
devices due to differences in both the magnitude and the composition of the emissions:
the conventional wood stove,
the noncatalytic wood stove,
the catalytic wood stove,
the pellet stove, and
the masonry heater.
Among these categories, there are many variations in device design and operation characteristics.
The conventional stove category comprises all stoves without catalytic combustors not included
in the other noncatalytic categories (i.e., noncatalytic and pellet). Conventional stoves do not have any
emission reduction technology or design features and, in most cases, were manufactured before July 1,
1986. Stoves of many different airflow designs may be in this category, such as updraft, downdraft,
crossdraft and S-flow.
Noncatalytic wood stoves are those units that do not employ catalysts but do have emission
reducing technology or features. Typical noncatalytic design includes baffles and secondary combustion
chambers.
Catalytic stoves are equipped with a ceramic or metal honeycomb device, called a combustor or
converter, that is coated with a noble metal such as platinum or palladium. The catalyst material reduces
the ignition temperature of the unburned volatile organic compounds (VOC) and carbon monoxide (CO)
in the exhaust gases, thus augmenting their ignition and combustion at normal stove operating
temperatures. As these components of the gases burn, the temperature inside the catalyst increases to a
point at which the ignition of the gases is essentially self sustaining.
Pellet stoves are those fueled with pellets of sawdust, wood products, and other biomass
materials pressed into manageable shapes and sizes. These stoves have active air flow systems and
unique grate design to accommodate this type of fuel. Some pellet stove models are subject to the 1988
New Source Performance Standards (NSPS), while others are exempt due to a high air-to-fuel ratio (i.e.,
greater than 35-to-l).
Masonry heaters are large, enclosed chambers made of masonry products or a combination of
masonry products and ceramic materials. These devices are exempt from the 1988 NSPS due to their
weight (i.e., greater than 800 kg). Masonry heaters are gaining popularity as a cleaner burning and heat
10/92 1.10-1
-------
efficient form of primary and supplemental heat, relative to some other types of wood heaters. In a
masonry heater, a complete charge of wood is burned in a relatively short period of time. The use of
masonry materials promotes heat transfer. Thus, radiant heat from the heater warms the surrounding area
for many hours after the fire has burned out.
4-30
1.10.2 Emissions
The combustion and pyrolysis of wood in wood stoves produce atmospheric emissions of
particulate matter, carbon monoxide, nitrogen oxides, organic compounds, mineral residues, and to a
lesser extent, sulfur oxides. The quantities and types of emissions are highly variable, depending on a
number of factors, including stage of the combustion cycle. During initial burning stages, after a new
wood charge is introduced, emissions (primarily VOCs) increase dramatically. After the initial period of
high burn rate. There is a charcoal stage of the burn cycle, characterized by a slower burn rate and
decreased emissions. Emission rates during this stage are cyclical, characterized by relatively long
periods of low emissions and shorter episodes of emission spikes.
Particulate emissions are defined in this discussion as the total catch measured by the EPA
Method 5H (Oregon Method 7) sampling train.1 A small portion of wood stove particulate emissions
includes "solid" particles of elemental carbon and wood. The vast majority of particulate emissions is
condensed organic products of incomplete combustion equal to or less than 10 micrometers in
aerodynamic diameter (PM-10). Although reported particle size data are scarce, one reference states that
95 percent of the particles emitted from a wood stove were less than 0.4 micrometers in size.4
Sulfur oxides (SOX) are formed by oxidation of sulfur in the wood. Nitrogen oxides (NOX) are
formed by oxidation of fuel and atmospheric nitrogen. Mineral constituents, such as potassium and
sodium compounds, are released from the wood matrix during combustion.
The high levels of organic compound and CO emissions are results of incomplete combustion of
the wood. Organic constituents of wood smoke vary considerably in both type and volatility. These
constituents include simple hydrocarbons of carbon numbers 1 through 7 (Cl - C7) (which exist as gases
or which volatilize at ambient conditions) and complex low volatility substances that condense at
ambient conditions. These low volatility condensible materials generally are considered to have boiling
points below 300°C (572°F).
Poly cyclic organic matter (POM) is an important component of the condensible fraction of wood
smoke. POM contains a wide range of compounds, including organic compounds formed through
incomplete combustion by the combination office radical species in the flame zone. This group which is
classified as a Hazardous Air Pollutant (HAP) under Title III of the 1990 Clean Air Act Amendments
contains the sub-group of hydrocarbons called Poly cyclic Aromatic Hydrocarbons (PAH).
Emission factors and their ratings for wood combustion in residential wood stoves, pellet stoves
and masonry heaters are presented in Tables 1.10-1 through 1.10-8. These tables include emission
factors for criteria pollutants (PM-10, CO, NOX, SOX), CO2, Total Organic Compounds (TOC), speciated
organic compounds, PAH, and some elements. The emission factors are presented by wood heater type.
PM-10 and CO emission factors are further classified by stove certification category. Phase II stoves are
those certified to meet the July 1, 1990 EPA standards; Phase I stoves meet the July 1, 1988 EPA
standards; and Pre-Phase I stoves do not meet any of the EPA standards but in most cases do meet the
Oregon 1986 certification standards.1 The emission factors for PM and CO in Tables 1.10-1 and 1.10-2
1.10-2 10/92
-------
are averages, derived entirely from field test data obtained under actual operating conditions. Still, there
is a potential for higher emissions from some wood stove, pellet stove and masonry heater models.
As mentioned, particulate emissions are defined as the total emissions equivalent to that
collected by EPA Method 5H. This method employs a heated filter followed by three impingers, an
unheated filter, and a final impinger. Particulate emissions factors are presented as values equivalent to
that collected with Method 5H. Conversions are employed, as appropriate, for data collected with other
methods. See Reference 2 for detailed discussions of EPA Methods 5H and 28.
Table 1.10-7 shows net efficiency by device type, determined entirely from field test data. Net or
overall efficiency is the product of combustion efficiency multiplied by heat transfer efficiency. Wood
heater efficiency is an important parameter used, along with emission factors and percent degradation,
when calculating PM-10 emission reduction credits. Percent degradation is related to the loss in
effectiveness of a wood stove control device or catalyst over a period of operation. Control degradation
for any stove, including noncatalytic wood stoves, may also occur as a result of deteriorated seals and
gaskets, misaligned baffles and bypass mechanisms, broken refractories, or other damaged functional
components. The increase in emissions which can result from control degradation has not been
quantified. However, recent wood stove testing in Colorado and Oregon should produce results which
allow estimation of emissions as a function of stove age.
10/92
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TABLE 1.10-1. (ENGLISH UNITS) EMISSION FACTORS FOR RESIDENTIAL
WOOD COMBUSTION3
Pollutant/
EPA Certification13
Emission
Factor
Rating
Wood Stove Type0
Conv.
Ib/ton
Non-Cat
Ib/ton
Cat
Ib/ton
Pellet Stove Typed
Certified
Ib/ton
Exempt
Ib/ton
Masonry
Heater
Exempt6
Ib/ton
PM-10f-g
Pre-Phasel B 30.6 25.8 24.2
Phase I B 20.0 19.6
Phase II B 14.6 16.2
All B 30.6 19.6 20.4
Carbon Monoxidef
4.2
4.2
5.6
Pre-Phase I
Phase I
Phase II
All
Nitrogen Oxidesf
Sulfur Oxide sf
Carbon DioxideJ
Total Organic
Compounds'^
Methane
Non-Methane
a. Units are in
b. Pre-Phase I
B 230.8
B
B
B 230.8
2.8h
B 0.4
C
E 64.0
E 28.0
(Ibs. of pollutant/ton of dry
= not certified to 1988 EPA
104.4
140.8 107.0 39.4
140.8 104.8 39.4 52.2 149.0
2.01 13.81
0.4 0.4 0.4
2,951.6 3,671.2 3,849.4
26.0
17.2
wood burned).
emission standards; Phase I = certified to 1988 EPA
emission standards; Phase II = certified to 1990 EPA emission standards; All = average of
emission factors for all devices.
c. Conv = Conventional; Non-Cat = Noncatalytic; Cat = Catalytic.
d. Certified = Certified pursuant to 1988 NSPS; Exempt = Exempt from 1988 NSPS (i.e., airfuel
ratio >35:1).
e. Exempt = Exempt from 1988 NSPS (i.e., weight >800 kg).
f. References 5-13, 22-26, 28.
g. Defined as equivalent to total catch by EPA method 5H train.
h. Rating = C.
i. Rating = E.
j. References 12, 22-26, 28.
k. References 14, 15, 18. The data used to develop the emission factors showed a high degree of
variability within the source population. The use of these emission factors on specific sources
may not be appropriate.
1.10-4
10/92
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TABLE 1.10-2. (METRIC UNITS) EMISSION FACTORS FOR RESIDENTIAL
WOOD COMBUSTION3
Pollutant/
EPA Certification13
Emission
Factor
Rating
Wood Stove Type0
Conv.
g/kg
Non-Cat
g/kg
Cat
g/kg
Pellet Stove Typed
Certified
g/kg
Exempt
g/kg
Masonry
Heater
Exempt6
g/kg
PM-10f-g
Pre-Phasel B 15.3 12.9 12.1
Phase I B 10.0 9.8
Phase II B 7.3 8.1
All B 15.3 9.8 10.2
Carbon Monoxidef
2.1
2.1
4.4
Pre-Phase I
Phase I
Phase II
All
Nitrogen Oxidesf
Sulfur Oxide sf
Carbon DioxideJ
Total Organic
Compounds'^
Methane
Non-Methane
a. Units are in
b. Pre-Phase I
B 115.4
B
B 70.4
B 115.4 70.4
1.4h
B 0.2 0.2
C
E 32.0
E 14.0
52.2
53.5 19.7
52.4 19.7 26.1 74.5
l.O1 6.91
0.2 0.2
1,475.8 1,835.6 1,924.7
13.0
8.6
(grams of pollutant/kg of dry wood burned).
= not certified to 1988 EPA emission standards; Phase I = certified to 1988 EPA
emission standards; Phase II = certified to 1990 EPA emission standards; All = average of
emission factors for all devices.
c. Conv = Conventional; Non-Cat = Noncatalytic; Cat = Catalytic.
d. Certified = Certified pursuant to 1988 NSPS; Exempt = Exempt from 1988 NSPS (i.e., airfuel
ratio >35:1).
e. Exempt = Exempt from 1988 NSPS (i.e., weight >800 kg).
f. References 5-13, 22-26, 28.
g. Defined as equivalent to total catch by EPA method 5H train.
h. Rating = C.
i. Rating = E.
j. References 12, 22-26, 28.
k. References 14, 15, 18. The data used to develop the emission factors showed a high degree of
variability within the source population. The use of these emission factors on specific sources
may not be appropriate.
10/92
1.10-5
-------
TABLE 1.10-3. (ENGLISH AND METRIC UNITS) ORGANIC COMPOUND EMISSION FACTORS
FOR RESIDENTIAL WOOD COMBUSTION18
(Emission Factor Rating: E)a
Compounds
Cor
Ib/ton
Ethane 1.470
Ethylene 4.490
Acetylene 1.124
Propane 0.358
Propene 1 .244
i-Butane 0.028
n-Butane 0.056
Butenesc 1.192
Pentenesd 0.616
Benzene 1.938
Toluene 0.730
Furan 0.342
Methyl Ethyl Ketone 0.290
2-Methyl Furan 0.656
2,5-Dimethyl Furan 0.162
Furfural 0.486
O-Xylene 0.202
WOOD STOVE TYPEb
iventional Catalytic
g/kg Ib/ton g/kg
0.735 1.376 0.688
2.245 3.482 1.741
0.562 0.564 0.282
0.179 0.158 0.079
0.622 0.734 0.367
0.014 0.010 0.005
0.028 0.014 0.007
0.596 0.714 0.357
0.308 0.150 0.075
0.969 1.464 0.732
0.365 0.520 0.260
0.171 0.124 0.062
0.145 0.062 0.031
0.328 0.084 0.042
0.081 0.002 0.011
0.243 0.146 0.073
0.101 0.186 0.093
a. The data used to develop the emission factors showed a high degree of variability within the
source population. The use of these emission factors on specific sources may not be
appropriate.
b. Units are in Ib/ton (Ibs. of pollutant/ton of dry wood burned).
c. 1-butene, i-butene, t-2-butene, c-2-butene, 2-me-l-butene, 2-me-butene are reported as
butenes.
d. 1-pentene, t-2-pentene, and c-2-pentene are reported as pentenes.
1.10-6
10/92
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TABLE 1.10-4. (ENGLISH UNITS) POLYCYCLIC AROMATIC HYDROCARBON (PAH)
EMISSION FACTORS FOR RESIDENTIAL WOOD COMBUSTION3
(Emission Factor Rating: E)b
Pollutant
STOVE TYPE
Conventional0
Ib/ton
Noncatalyticd
Ib/ton
Catalytic6
Ib/ton
Exempt Pelletf
Ib/ton
PAH
Acenaphthene 0.010
Acenaphthylene 0.212
Anthracene 0.014
Benzo(a) Anthracene 0.020
Benzo(b)Fluoranthene 0.006
Benzo(g,h,i)Fluoranthene
Benzo(k)Fluoranthene 0.002
Benzo(g,h,i)Perylene 0.004
Benzo(a)Pyrene 0.004
Benzo(e)Pyrene 0.012
Biphenyl
Chrysene 0.012
Dibenzo(a,h) Anthracene 0.000
7,12-Dimethylbenz(a)Anthracene
Fluoranthene 0.020
Fluorene 0.024
Indeno(l,2,3,cd)Pyrene 0.000
9-Methylanthracene
12-Methylbenz(a)Anthracene
3 -Methylchlolanthrene
1 -Methylphenanthrene
Naphthalene 0.288
Nitronaphthalene
Perylene
Phenanthrene 0.078
Phenanthrol
Phenol
Pyrene 0.024
PAH Total 0.730
0.010
0.032
0.009
<0.001
0.004
0.028
<0.001
0.020
0.006
0.002
0.022
0.010
0.004
0.004
0.008
0.014
0.020
0.004
0.002
<0.001
0.030
0.144
0.000
0.002
0.118
0.000
<0.001
0.008
0.500
0.006
0.068
0.008
0.024
0.004
0.006
0.002
0.002
0.004
0.004
0.010
0.002
0.012
0.014
0.004
0.186
0.489
0.010
0.414
2.60E-05
7.52E-05
5.48E-05
3.32E-05
4.84E-05
a. Units are in Ib/ton (Ibs. of pollutant/ton of dry wood burned).
b. The data used to develop these emission factors showed a high degree of variability within the source
population and/or came from a small number of sources. The use of these emission factors on specific
sources may not be appropriate.
c. Reference 18.
d. References 16,19-21.
e. References 15-19.
f Reference 28. Exempt = Exempt from 1988 NSPS (i.e., airfuel ratio >35:1).
10/92
1.10-7
-------
TABLE 1.10-5. (METRIC UNITS) POLYCYCLIC AROMATIC HYDROCARBON (PAH) EMISSION
FACTORS FOR RESIDENTIAL WOOD COMBUSTION3
(Emission Factor Rating: E)b
Pollutant
STOVE TYPE
Conventional0
g/kg
Noncatalyticd
g/kg
Catalytic6
g/kg
Exempt Pelletf
g/kg
PAH
Acenaphthene 0.005
Acenaphthylene 0.106
Anthracene 0.007
Benzo(a) Anthracene 0.010
Benzo(b)Fluoranthene 0.003
Benzo(g,h,i)Fluoranthene
Benzo(k)Fluoranthene 0.001
Benzo(g,h,i)Perylene 0.002
Benzo(a)Pyrene 0.002
Benzo(e)Pyrene 0.006
Biphenyl
Chrysene 0.006
Dibenzo(a,h) Anthracene 0.000
7,12-Dimethylbenz(a)Anthracene
Fluoranthene 0.010
Fluorene 0.012
Indeno(l,2,3,cd)Pyrene 0.000
9-Methylanthracene
12-Methylbenz(a)Anthracene
3 -Methylchlolanthrene
1 -Methylphenanthrene
Naphthalene 0.144
Nitronaphthalene
Perylene
Phenanthrene 0.039
Phenanthrol
Phenol
Pyrene 0.012
PAH Total 0.365
0.005
0.016
0.004
<0.001
0.002
0.014
<0.001
0.010
0.003
0.001
0.011
0.005
0.002
0.002
0.004
0.007
0.010
0.002
0.001
<0.001
0.015
0.072
0.000
0.001
0.059
0.000
<0.001
0.004
0.250
0.003
0.034
0.004
0.012
0.002
0.003
0.001
0.001
0.002
0.002
0.005
0.001
0.006
0.007
0.002
0.093
0.024
0.005
0.207
1.30E-05
3.76E-05
2.74E-05
1.66E-05
2.42E-05
a. Units are in g/kg (grams of pollutant/kg of dry wood burned).
b. The data used to develop these emission factors showed a high degree of variability within the source
population and/or came from a small number of sources. The use of these emission factors on specific
sources may not be appropriate.
c. Reference 18.
d. References 16,19-21.
e. References 15-19.
f Reference 28. Exempt = Exempt from 1988 NSPS (i.e., airfuel ratio >35:1).
1.10-8
10/92
-------
TABLE 1.10-6. (ENGLISH AND METRIC UNITS) TRACE ELEMENT EMISSION FACTORS FOR
RESIDENTIAL WOOD COMBUSTION3
(Emission Factor Rating: E)b
Element
WOOD STOVE TYPE
Conventional
Ib/ton g/kg
Noncatalytic
Ib/ton g/kg
Catalytic
Ib/ton g/kg
Cadmium (Cd) 2.2E-05 1.1E-05 2.0E-05 l.OE-05 4.6E-05 2.3E-05
Chromium (Cr) <1.0E-06 <1.0E-06 <1.0E-06 <1.0E-05 <1.0E-06 <1.0-E06
Manganese (Mn) 1.7E-04 8.7E-05 1.4E-04 7.0E-05 2.2E-04 1.1E-04
Nickel (Ni) 1.4E-05 7.0E-06 2.0E-05 l.OE-05 2.2E-06 l.OE-06
a. Units are in Ib/ton (Ibs. of pollutant/ton of dry wood burned) and g/kg (grams of pollutant/kg of
dry wood burned). Emission factors are based on data from References 15 and 18.
b. The data used to develop these emission factors showed a high degree of variability within the
source population. The use of these emission factors on a specific source may not be
appropriate.
TABLE 1.10-7. SUMMARY OF WOOD HEATER NET EFFICIENCIES3
Wood Heater Type
Wood Stoves
Conventional
Non-Catalytic
Catalytic
Pellet Stovesb
Certified
Exempt
Masonry Heaters
All
Net Efficiency (%)
54
68
68
68
56
58
Reference
27
10, 13,27
7,27
12
28
29
a. Net efficiency is a function of both combustion efficiency and heat transfer efficiency.
The percentages shown here are based on data collected from in-home testing.
b. Certified = Certified pursuant to 1988 NSPS.
Exempt = Exempt from 1988 NSPS (i.e., airfuel ratio >35:1).
10/92
1.10-9
-------
References for Section 1.10
1. Standards Of Performance For New Stationary Sources: New Residential Wood Heaters. 53 FR
5573, February 26, 1988.
2. Weant, G. E., Emission Factor Documentation For AP-42 Section 1.10: Residential Wood Stoves.
EPA-450/4-89-007, U. S. Environmental Protection Agency, Research Triangle Park, NC, May
1989.
3. Gay, R., and J. Shah, Technical Support Document For Residential Wood Combustion. EPA-450/4-
85-012, U. S. Environmental Protection Agency, Research Triangle Park, NC, February 1986.
4. Rau, J. A., and J. J. Huntzicker, Composition And Size Distribution Of Residential Wood Smoke
Aerosols. Presented at the 21st Annual Meeting of the Air and Waste Management Association,
Pacific Northwest International Section, Portland, OR, November 1984.
5. Simons, C. A., et al., Whitehorse Efficient Woodheat Demonstration. The City of Whitehorse,
Whitehorse, Yukon, Canada, September 1987.
6. Simons, C. A., et al., Woodstove Emission Sampling Methods Comparability Analysis And In-situ
Evaluation Of New Technology Woodstoves. EPA-600/7-89-002, U. S. Environmental Protection
Agency, Cincinnati, OH, January 1989.
7. Barnett, S. G., Field Performance Of Advanced Technology Woodstoves In Glens Falls. N.Y. 1988-
1989.. Vol. 1, New York State Energy Research And Development Authority, Albany, NY, October
1989.
8. Burnet, P. G., The Northeast Cooperative Woodstove Study. Volume 1, EPA-600/7-87-026a, U. S.
Environmental Protection Agency, Cincinnati, OH, November 1987.
9. Jaasma, D. R., and M. R. Champion, Field Performance Of Woodburning Stoves In Crested Butte
During The 1989-90 Heating Season. Town of Crested Butte, Crested Butte, CO, September 1990.
10. Dernbach, S., Woodstove Field Performance In Klamath Falls. OR. Wood Heating Alliance,
Washington, D. C., April 1990.
11. Simons. C. A., and S. K. Jones. Performance Evaluation Of The Best Existing Stove Technology
(BEST) Hybrid Woodstove And Catalytic Retrofit Device. Oregon Department Of Environmental
Quality, Portland, OR, July 1989.
12. Barnett, S. G., and R. B. Roholt, In-home Performance Of Certified Pellet Stoves In Medford And
Klamath Falls. OR. U. S. Department Of Energy Report No. PS407-02, July 1990.
13. Barnett, S. G., In-Home Evaluation of Emission Characteristics of EPA-Certified High-Tech Non-
Catalytic Woodstoves in Klamath Falls. OR. 1990. prepared for the Canada Center for Mineral and
Energy Technology, Energy, Mines and Resources, Canada, DSS File No. 145Q, 23440-9-9230,
June 1, 1990.
1.10-10 10/92
-------
References for Section 1.10 (continued)
14. McCrillis, R. C., and R. G. Merrill, Emission Control Effectiveness Of A Woodstove Catalyst And
Emission Measurement Methods Comparison. Presented at the 78th Annual Meeting of the Air And
Waste Management Association, Detroit, MI, 1985.
15. Leese. K. E.. and S. M. Harkins. Effects Of Burn Rate. Wood Species. Moisture Content And
Weight Of Wood Loaded On Woodstove Emissions. EPA 600/2-89-025, U. S. Environmental
Protection Agency, Cincinnati, OH, May 1989.
16. Allen, J. M., and W. M. Cooke, Control Of Emissions From Residential Wood Burning By
Combustion Modification. EPA-600/7-81-091, U. S. Environmental Protection Agency, Cincinnati,
OH, May 1981.
17. DeAngelis, D. G., et al., Preliminary Characterization Of Emissions From Wood-fired Residential
Combustion Equipment. EPA-600/7-80-040, U. S. Environmental Protection Agency, Cincinnati,
OH, March 1980.
18. Burnet. P. G.. et al.. Effects of Appliance Type and Operating Variables on Woodstove Emissions.
Vol. I. Report and Appendices 6-C, EPA-600/2-90-001a, U.S. Environmental Protection Agency,
Research Triangle Park, NC, January 1990.
19. Cottone, L. E., and E. Mesner, Test Method Evaluations and Emissions Testing for Rating Wood
Stoves. EPA-600/2-86-100, U.S. Environmental Protection Agency, Research Triangle Park, NC,
October 1986.
20. Residential Wood Heater Test Report. Phase II Testing, Vol. 1, TVA, Division of Energy,
Construction and Rates, Chattanooga, TN, August 1983.
21. Truesdale, R. S. and J. G. Cleland, Residential Stove Emissions from Coal and Other Alternative
Fuels Combustion, in papers at the Specialty Conference on Residential Wood and Coal
Combustion, Louisville, KY, March 1982.
22. Barnett, S. G., In-Home Evaluation of Emissions From Masonry Fireplaces and Heaters. OMNI
Environmental Services, Inc., Beaverton, OR, September 1991.
23. Barnett, S. G., In-Home Evaluation of Emissions From a Grundofen Masonry Heater. OMNI
Environmental Services, Inc., Beaverton, OR, January 1992.
24. Barnett, S. G., In-Home Evaluation of Emissions From a Tulikivi KTU 2100 Masonry Heater.
OMNI Environmental Services, Inc., Beaverton, OR, March 1992.
25. Barnett, S. G., In-Home Evaluation of Emissions From a Royal Crown 2000 Masonry Heater. OMNI
Environmental Services, Inc., Beaverton, OR, March 1992.
26. Barnett, S. G., In-Home Evaluation of Emissions From a Biofire 4x3 Masonry Heater. OMNI
Environmental Services, Inc., Beaverton, OR, March 1992.
10/92 1.10-11
-------
References for Section 1.10 (concluded)
27. Barnett, S. G. and R. D. Bighouse, In-Home Demonstrations of the Reduction of Woodstove
Emissions from the use of Densified Logs. Oregon Department of Energy and U.S. Environmental
Protection Agency, July 1992.
28. Barnett, S. G. and P. G. Fields, In-Home Performance of Exempt Pellet Stoves in Medford. Oregon.
U. S. Department of Energy, Oregon Department of Energy, Tennessee Valley Authority, and
Oregon Department of Environmental Quality, July 1991.
29. Barnett, S. G., Summary Report of the In-Home Emissions and Efficiency Performance of Five
Commercially Available Masonry Heaters, the Masonry Heater Association, May 1992.
30. Guidance Document for Residential Wood Combustion Emission Control Measures. EPA-450/2-89-
015 Errata Sheet, Office of Air Quality Planning and Standards, U. S. Environmental Protection
Agency, Research Triangle Park, NC, 27711, June 1991.
1.10-12 10/92
-------
APPENDIX A
SAMPLE CALCULATIONS AND EPA METHOD 5G CORRELATION EQUATIONS
-------
SAMPLE CALCULATIONS
GIVEN:
Participate sampling using AWES and VPI units
rr
Emission Rate = 9.8 —
hr
Burn Rate = 1.47 -^
hr
FIND:
Equivalent M5H Emission Factor (g/kg, Ib/ton)
SOLUTION:
AWES: Convert g/hr to M5G equivalent
Calculate g/kg
M5G = 0.8635(9.8)°'9288 = 7.2 g/hr
M5H = 1.619(7.2)°'905 = 9.7 g/hr
9'7 g/hr = 6.6 g/kg =13.1 Iblton
1.47
VPI: Convert g/hr to M5G equivalent
M5G = 0.6748(9.8)L007 = 6.7 g/hr
Convert M5G to M5H
M5H = 1.619(6.7)°'905 = 9.1 g/hr
Calculate g/kg
9.1
1.47 kg/hr
= 6.2 e/A- = 12.4
A-2
-------
APPENDIX B
MARKED-UP PREVIOUS AP-42 SECTION 1.10
-------
LINEAR REGRESSION FOR DEVELOPMENT OF "AWES" to M5G COORELATION
Septembers, 1992
AWES
Reference:
5G
23.3
3.15
1.5
2.47
0.74
0.74
12.9
17.4
6.73
11.82
3.21
5.95
6.2
4.43
LN5G
3.1484533606
1.1474024528
0.4054651081
0.9042181506
-0.301105093
-0.301105093
2.5572273114
2.8564702062
1.9065751437
2.469793012
1.1662709371
1.7833912196
1.8245492921
1.4883995841
S.G. Barnett, "Relationship of the AWES to EPA Methods 5H and 5G"
OMNI Environmental Services, December 15, 1991
Prepared for R.C. McCrillis, U.S. EPA, AEERL, RTF, NC 2771 1
AWES
27.1
3.5
4.1
4.2
0.87
0.8
22.3
22.4
9.25
17.13
2.6
9.5
6.61
4.35
LN AWES
3.29953372789
1.2527629685
1.41098697371
1.43508452529
-0.1392620673
-0.2231435513
3.10458667847
3.10906095886
2.22462355152
2.84083131234
0.95551144503
2.25129179861
1.88858365386
1.4701758451
Constant
Regression Output:
StdErrofYEst
R Squared
No. of Observations
Degrees of Freedom
X Coefficients)
StdErrofCoef.
R
=======
5G = C * (AWES) AA
C = exp(Constant)=
A = X Coefficient=
0.9288379
0.0748238
0.9631998
0.8635
0.9288
5G = 0.8635*(AWES)A0.9288
-0.146719
0.3029377
0.9277539
14
12
4-6
10/92
-------
For Graphing:
Sorted "X"
0.8
0.87
2.6
3.5
4.1
4.2
4.35
6.61
9.25
9.5
17.13
22.3
22.4
27.1
Sorted "Y"
0.74
0.74
3.21
3.15
1.5
2.47
4.43
6.2
6.73
5.95
11.82
12.9
17.4
23.3
5G = 0.8635*(AWES)A0.9288
0.702
0.759
2.098
2.765
3.202
3.275
3.383
4.99
6.818
6.989
12.08
15.44
15.5
18.5
10/92
4-7
-------
LINEAR REGRESSION FOR DEVELOPMENT OF "VPI" to M5G COORELATION
Septembers, 1992
VPI
Reference:
G.E. Weant, "Emissions Factor Document for AP-42: Section 1.10,
Residential Wood Stoves", Engineering-Science, December 1991
Prepared for U.S. EPA, OAQPS, RTF, NC 2771 1
Revised: 9/10/92 per D.R. Jaasma, et.al, "Woodstove Smoke and CO Emissions: Comparison
of Reverence Methods with the VPI Sampler", in Proceedings,
83rd Annual AWMA Meeting, Paper 90-80.5, June 1990.
5G
0.6
0.9
1.1
1.3
1.4
1.4
1.4
2.0
4.1
4.4
A S
LN5G
-0.51919387
-0.13926207
0.12663265
0.24686008
0.31481074
0.32570014
0.36464311
0.66782937
1.41098697
1.47017585
i ^n/irm/m
VPI
1.0
1.8
1.8
2.5
2.7
2.1
3.2
2.6
4.0
4.9
<; n
LNVPI
0.00000000
0.55961579
0.58778666
0.91629073
0.99325177
0.74193734
1.16315081
0.93609336
1.38629436
1.58923521
i Ana/mai
Constant
Regression Output:
StdErrofYEst
R Squared
No. of Observations
Degrees of Freedom
X Coefficient(s)
StdErrofCoef.
R
1.0067
0.0268
0.9864177
-0.3949
0.1947
0.9730
41
39
10/92
4-9
-------
4.9
5.5
6.3
7.0
7.5
8.8
10.0
10.1
11.1
11.9
12.2
12.3
12.3
13.7
13.8
14.8
15.4
15.8
17.8
18.3
18.8
21.0
22.8
24.5
26.6
31.6
32.5
46.1
1.58923521
1.70656462
1.84054963
1.95302762
2.01356880
2.17304572
2.30757263
2.31648800
2.40694511
2.47401421
2.50389195
2.50715726
2.50959926
2.61958322
2.62756295
2.69799987
2.73760900
2.76190687
2.87919846
2.90690106
2.93598227
3.04309284
3.12478490
3.19867312
3.28241385
3.45189050
3.48000856
3.83081295
6.8
6.7
7.7
10.9
9.2
12.9
11.2
16.6
12.3
16.6
20.8
25.4
15.0
16.2
19.0
22.9
23.8
20.9
25.7
33.1
31.3
30.4
30.0
38.3
38.5
39.6
44.1
65.3
1.91692261
1.90210753
2.04122033
2.38876279
2.21920348
2.55722731
2.41591378
2.80940270
2.50959926
2.80940270
3.03495299
3.23474917
2.70805020
2.78809291
2.94180393
3.13113691
3.16758253
3.03974916
3.24649099
3.49953328
3.44361810
3.41444261
3.40119738
3.64544990
3.65065824
3.67882912
3.78645978
4.17899204
5G = C * (VPI) AA
C = exp(Constant)=
A = X Coefficient=
0.6738
1.0067
5G = 0.6738*(VPI)A1.0067
4-10
10/92
-------
47.4
54.6
3.85862223
3.99911771
For Graphing:
Sorted "X"
1.0
1.8
1.8
2.1
2.5
2.6
2.7
3.2
4.0
4.9
5.0
6.7
6.8
7.7
9.2
10.9
11.2
12.3
12.9
15.0
16.2
16.6
16.6
77.9
100.7
4.35542595
4.61214580
Sorted "Y"
0.6
0.9
1.1
1.4
1.3
2.0
1.4
1.4
4.1
4.4
4.5
5.5
4.9
6.3
7.5
7.0
10.0
11.1
8.8
12.3
13.7
11.9
10.1
5G = 0.6738*(VPI)A1.0067
0.674
1.184
1.218
1.422
1.695
1.729
1.831
2.173
2.72
3.337
3.405
4.572
4.641
5.259
6.291
7.462
7.669
8.428
8.841
10.29
11.15
11.4
11.4
10/92
4-11
-------
19.0
20.8
20.9
22.9
23.8
25.4
25.7
30.0
30.4
31.3
33.1
38.3
38.5
39.6
44.1
65.3
77.9
100.7
13.8
12.2
15.8
14.8
15.4
12.3
17.8
22.8
21.0
18.8
18.3
24.5
26.6
31.6
32.5
46.1
47.4
54.6
13.02
14.3
14.37
15.76
16.34
17.49
17.7
20.68
20.96
21.58
22.83
26.44
26.58
27.35
30.47
45.24
54.04
69.97
4-12
10/92
------- |