United States
Environmental Protection
Agency
Atmospheric Research and Exposure \ '',,»
Assessment Laboratory .^ •
Research Triangle Park NC 27711 -^ ^
Research and Development
EPA/600/S3-89/051 Aug. 1989 '/, * \
&EPA Project Summary
Quality Assurance Procedures:
Method 28A Measurement of
Air to Fuel Ratio and Minimum
Burn Rate for Wood-Fired
Appliances
R. C. Olin, G. D. Rives, M. W. Hartman, and T. E. Ward
The full report is a comprehensive
document intended to be used as an
aid for wood heater manufacturers
and testing laboratories in performing
measurement of air-to-fuel ratio and
minimum burn rate determinations
according to EPA protocol, Method
28A. These procedures may be used
in research and development, and as
an aid in auditing and certification
applicability testing. A detailed, step-
by-step quality assurance guide is
provided to aid in the procurement
and assembly of testing apparatus, to
clearly describe the procedures, and
to facilitate data collection and
reporting. Suggested data sheets are
supplied that can be used as an aid
for both recordkeeping and certi-
fication applications. Throughout the
document, activity matrices are pro-
vided to serve as a summary refer-
ence. Checklists are also supplied
that can be used by testing
personnel. Finally, for the purposes
of ensuring data quality, procedures
are outlined for apparatus operation,
maintenance, and traceability. These
procedures combined with the
detailed description of the sampling
and analysis protocol will help
ensure the accuracy and reliability of
Method 28A testing results.
This Project Summary was devel-
oped by EPA's Atmospheric Research
and Exposure Assessment Laboratory,
Research Triangle Park, NC, to an-
nounce key findings of the research
project that is fully documented in a
separate report of the same title (see
Project Report ordering information at
back).
Introduction
Quality Assurance Procedures: Method
28A, Measurement of Air to Fuel Ratio
and Minimum Burn Rate for Wood-Fired
Appliances has been prepared as an aid
for wood heater manufacturers and
testing laboratories in performing wood
heater procedures specified in Method
28A and in ensuring data quality and
reliability. This manual may be used in
combination with Method 28A for
designing an individualized quality assur-
ance program.
Method Highlights
EPA Method 28A contains all the
requirements and describes the
apparatus and procedures for measuring
minimum burn rate and air-to-fuel ratio
for wood heaters. The apparatus and
procedures used are similar to those
used for Method 28, "Certification and
Auditing of Wood Heaters." Method 28A
is unique in that its purpose is to
determine whether further particulate
emissions testing is required. Thus,
Method 28A focuses on wood heater
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process characteristics rather than
emissions. However, stack gas analysis
(for C02, 02, and CO) is used to
calculate process parameters (i.e., air-to-
fuel ratios). To get accurate and re-
peatable results, it is extremely important
to follow the procedures described in
Method 28A closely. Following the test
procedures closely is ultimately to the
advantage of both the wood heater
manufacturer and the test laboratory.
Quality Assurance Procedures
Highlights
These procedures, Quality Assurance
Procedures: Method 28A, Measurement
of Air to Fuel Ratio and Minimum Burn
Rate for Wood-Fired Appliances, are to
be used as an aid in assembling the
testing apparatus, to list and describe the
required procedures, and to facilitate the
data recording. Activity matrices are
provided at the end of the appropriate
sections. Section 12.0 contains blank
data sheets which can be reproduced
and used as an aid in data collection and
recording. Examples of the use of these
sheets are given in the appropriate
sections of this Manual.
Section 1.0 presents the specifications,
criteria, and design features for the
equipment and materials that are
required to set up and operate a wood
heater according to Method 28A. This
section is intended to inform the user of
the apparatus selection options and the
rationale for selecting a particular piece
of equipment or analytical method. The
activity matrix given at the end of Section
1.0 can be used as a convenient checklist
for equipment procurement and initial
acceptance check procedures.
Section 2.0 provides an item-by-item,
step-by-step guide to the required
calibration procedures and frequencies.
Some of the apparatus (e.g., platform
scale, moisture content meter, and instru-
mental analyzers) require calibrations
before each test run while other pieces of
apparatus require calibration semian-
nually.
Section 3.0 describes procedures that
are conducted before gas sampling
begins. These procedures include firebox
volume measurements, wood heater
installation, apparatus check and calibra-
tion, test fuel measurements and crib
construction, measurement of the facility
conditions, and presampling burn
activities. Illustrations, examples, and an
activity checklist are provided to assist
testing personnel in performing and
documenting pretest procedures. An
activity matrix provides a summary of the
purpose, specifications, and time and
frequency of each pretest activity.
Section 4.0 lists and describes the
activities performed during the test run.
These activities include beginning the
test run, measurement of test run data at
10-minute intervals, adjustment of fuel
and air supply settings, test run
completion, and recording of data. An
activity matrix is provided listing in
chronological order each activity per-
formed during the test run.
Illustrations and examples are provided
to assist testing personnel in performing
and documenting test run activities.
Section 5.0 describes the activities
required at the end of the certification
test. These include: the measurement of
test facility condition parameters, sam-
pling train and equipment leak checks,
and either determination of gas
concentration using an Orsat analyzer or
data verification by span and zero drift
determination for Continuous Emission
Monitoring Systems (CEMS). Recom-
mended procedures also include per-
forming a calibration check on the
platform scale and measurement of the
fluid level in the liquid seal.
Section 6.0 describes calculations
necessary for interpreting the data
obtained. Calculations for determining dry
burn rate and air-to-fuel ratio are
provided. Also, calculations required to
determine F0, a fuel factor data qualiti
indicator, are described. Examples art
included. Section 7.0 summarizes recom
mendations on maintenance of equip
ment. Section 8.0 describes recommend
ed audit procedures, including botf
performance audits and system audits. /
table is provided that summarizes these
procedures. Section 9.0 recommends the
primary standards to which the wooc
heater operation and sample analysis
measurements are traceable.
Section 10.0 contains a copy o
Method 28A as published in the Federa
Register (40 CFR 60.530). Copies o
Methods 28 and 5H are also includec
since these are often referenced ir
Method 28A. Section 11.0 provides th<
reader with a list of the references use(
in the preparation of this manual. Sectioi
12.0 provides sheets that can be used fo
calculations, recordkeeping, and dat;
reporting. These sheets may be removec
and duplicated.
Conclusions and
Recommendations
It is concluded that these procedure:
will be helpful in ensuring and estab
lishing the quality of the data whei
sampling according to the requirement
of Method 28A. This will be beneficial fo
data producing activities including
research and development, and as an an
for certification applicability determina
tion.
These quality assurance procedure
may be used in the individualized qualit
assurance program established by eacl
user. Copies of the checklists am
summary activity matrices providei
herein may be supplied to testini
personnel to ensure that the desirei
quality assurance procedures are fol
lowed. Also, copies of blank data sheet
can aid the user in ensuring an
establishing data quality in samplin
activities.
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R. C. Olin, G. D. Rives, and M. W. Hartman, are with Radian Corporation,
Research Triangle Park, NC 27711; the EPA author, T. £. Ward (also the EPA
Project Officer, see below), is with the Atmospheric Research and Exposure
Assessment Laboratory, Research Triangle Park, NC 27711.
The complete report, entitled "Quality Assurance Procedures: Method 28A
Measurement of Air to Fuel Ratio and Minimum Burn Rate for Wood-Fired
Appliances," (Order No. PB 89-214 027'AS; Cost: $28.95, subject to change) will
be available only from:
National Technical Information Service
5285 Port Royal Road
Springfield, VA22161
Telephone: 703-487-4650
The EPA Project Officer can be contacted at:
Atmospheric Research and Exposure Assessment 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
EPA/600/S3-89/051
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