UNITEDSTATESENVIRONMENTALPROTECTION AGENCY 

Offtce of AIM Quality Planning and Standards 

Research Triangle Park, North Carolina 2771 1 

FEB 2 3 1990 

MEMORANDUM 

SUBJECT: Summary of Crested Butte Wood Heater Study - Preliminary 

FROM: William G. Laxton, Director 

Technical Support Division (MD 

TO: Distribution List 

Attached to this memorandum is a summary of the preliminary findings from 

the emission test program designed to evaluate the in-home test method to be 

applied in Crested Butte, Colorado. The purpose of this distribution is to 

alert you to several important indications resulting from these tests. The 

EPA program had two objectives: (1) to evaluate the Virginia Polytechnic 

Institute (VPI) in-home sampler relative to the EPA certification test method, 

and (2) to determine the effect of high altitude or low barometric pressure on 

wood heater emissions. The test series provided the following: 

a. the relationship between the measurements of the VP1 method and 

the EPA Method 56 was linear over the range of emissions from 1 to 

35 g/hr; 

b. the altitude effect on wood heater particulate emissions was not 

significant for the catalytic woodstove but may have been 

significant (about 25 percent at 8900 ft elevation) for the 

noncatalytic unit although the results were within the range of 

low altitude results by the accredited laboratories; 

C. the emissions from both the noncatalytic and the catalytic stoves 

increased about 7 g/hr from the certification test to the 

simulated in-home operation; and 

d. the Ashley stove, representing the type of unit being replaced in 

the Crested Butte homes, produced about twice the emissions 

produced by a certified noncatalytic wood heater - the Haugh's 

stove. 

The final report from the contractor is due in March and will include 

Colorado emission data in addition to the verified particulate emission 

results. 

If you have any questions about the test program or the results, contact 

Dennis Holzschuh (919) 541-5239 or Peter Westlin (919) 541-1059. 

Attachments (2) 
DISTRIBUTION 

EPA Reoional Air Divisions: 

Louis F. Gitto, Director 

Air, Pesticides and Toxics 

Management Division 

JFK Federal Bldg. 

Boston, MA 02203-2211 

Conrad Simon, Director 

Air & Waste Management Division 

26 Federal Plaza 

New York, NY 10278 

Thomas J. Maslany, Director 

Air Management Division 

841 Chestnut Building 

Philadelphia, PA 19107 

Winston A. Smith, Director 

Air, Pesticides, & Toxics 

Management Division 

345 Courtland Street, NE 

Atlanta, GA 30365 

David Kee, Director 

Air & Radiation Division 

230 South Dearborn Street 

Chicago, IL 60604 

Regional Environmental Services Division 

Edward J. Conley, Director 

Region I (EAA-LEX) 

New England Regional Laboratory 

60 Westview Street 

Lexington, MA 02173 

Barbara Metzger, Director 

Region II (ES/Bldg. 10) 

Woodbridge Avenue 

Edison, NJ 08817 

Greene A. Jones, Director 

Region III (3ESOO) 

841 Chestnut Building 

Philadelphia, PA 19107 

Bob Hanneschlager, Acting Director 

Air, Pesticides, & Toxics Div. 

1445 Ross Avenue 

Dallas, TX 25202-2733 

William A. Spratlin, Director 

Air & Toxics Division 

726 Minnesota Avenue 

Kansas City, KS 66101 

Irwin L. Dickstein, Director 

Air & Toxics Division 

999 18th Street 

Denver Place - Suite 500 

Denver, CO 80202-2405 

David P. Howekamp, Director 

Air & Toxics Division 

215 Fremont Street 

San Francisco, CA 94105 

Lyn McKee, Acting Director 

Air & Toxics Division 

1200 Sixth Avenue 

Seattle, WA 98101 

James H. Finger, Director 

Region IV 

College Station Road 

Athens, GA 30613 

William H. Sanders, III, Director 

Region V (5s) 

536 South Clark Street 

Chicago, IL 60605 

Russell F. Rhoades, Director 

Region VI (6E) 

1445 Ross Avenue 

Dallas, TX 75202-2733 
DISTRIBUTION (continued) 

Billy Fairless, Director 

Region VII 

25 Funston Road 

Kansas City, KS 66115 

James B. Lehr, Director 

Region VIII 

999 18th Street 

Denver Place - Suite 500 

Denver, CO 80202-2405 

Terry L. Stumph, Chief 

Environmental Services Branch 

Region XI 

215 Fremont Street 

San Francisco, CA 94105 

Robert G. Courson, Director 

Region X (ES-096) 

1200 Sixth Avenue 

Seattle, WA 98101 
UNITED STATES ENVIRONMENTAL PROTECTION AGENCY 

Office of Air Quality Planning and Standards 

Research Triangle Park, North Carolina 2771 1 

MEMORANDUM 

SUBJECT: Summary of Preliminary Data Comparing Certification and In-home 

Wood Heater Emission Test Methods 

FROM: Dennis Holzschuh, FTS (MD-l4m&qL 

Peter Westlin, TSS (MD-19) 

TO: Gilbert H. Wood, Chief 

Emission Measurement Branch (MD-14) 

Introduction 

The Emission Measurement Branch recently completed an evaluation of the 

field test method proposed for the Crested Butte, CO wood heater replacement 

and emission reduction program. The evaluation was undertaken in cooperation 

with the Air and Energy Engineering Research Laboratory, EPA Region 8, 

Colorado Department of Health, the Wood Heating Alliance, and the Crested 

Butte city council. The objectives of the method evaluation program were: 

1. Evaluate the in-home emission sampler developed by the Virginia 

Polytechnic Institute (VPI) Mechanical Engineering Department and 

develop an empirical relationship between the measurements from 

the VP1 sampler and EPA Method 56 used for certifying woodheaters; 

and 

2. Determine the effect of high altitude (low barometric pressure) on 

wood heater emissions. 

Summary of Program 

The test program was conducted in three phases. The first phase was to 

become familiar with the VP1 sampler and measurement procedure. Dennis Jaasma 

of VPI provided several sets of sampling equipment and on-site instruction on 

the operation, sample recovery and analysis, and calculation of results. EPA 

and the contractor, Engineering Science (ES), reviewed the procedure and 

developed an improved protocol for the laboratory and field testing portions 

of the program. 

The second phase was to compare the VP1 and Method 56 under conditions 

simulating certification testing. Two stoves, the Sweet Home AK-18 catalytic 

model and the Country Comfort CC-150 noncatalytic unit, were selected because 

they had been tested extensively during the EPA laboratory accreditation 
2 

program. Some modifications to the stove operation prescribed for certification tests were necessary to accommodate operation of the VP1 method. 

These modifications included repeating wood loadings to extend the operating 

time. The laboratory tests were completed at ES's RTP laboratory. 

The third phase involved additional comparison tests at 9000 ft altitude. 

Two more wood stoves were added to the testing program to obtain emission data 

for stoves typical of those being replaced and those to be installed in 

Crested Butte. The testing included two types of stove operation: (1) 

simulated certification test conditions for the AK-18 and the CC-150 

stoves, and (2) cord wood operation at a range of burn rates simulating 

in-home conditions for all four stoves. During the cord wood, -/-day tests, 

the VP1 sampler was operated at the low flow rate mode as would be applied in 

the in-home studv. Durinq the same period, the Method 56 train was operated 

of the seven daily Method 56 

lue for the same stove operating 

and recovered on"a dailv basis. The'average 

results were compared w:th the VP1 s ingle va 

period. 

Summary of Results 

Both the VP1 and the Method 56 trains were operated in pairs during the 

simulated certification testing so that between train or method precision 

could be determined. Experience with wood heater test methods indicates that 

method precision is on the order of 0.5 g/hr. Results of these comparisons 

will be discussed in the final report to be prepared by ES. The results 

discussed below concentrate on the comparison of the two methods and the 

altitude factor and are preliminary pending completion of the final report and 

EMB review. 

The attached table provides a summary of the average emission results for 

34 comparison tests representing over 150 sample train values. The data on 

the table are grouped by stove model with designations for location of the 

test and the wood loading configuration. The table also provides the average 

burn rate and emission rates for both sampling methods for each comparison 

test. The Method 56 data include corrections to Method 5H equivalent values 

as specified in the wood stove NSPS. The emission rate values represent 

averages of paired train results. Some of our observations about these 

preliminary results are as follows: 

1. The relationship between the results of the VP1 method and 

Method 56 is nearly linear. The VP1 method consistently 

produced an emission value greater than the corresponding 

Method 56 result. The cause for this difference was not explored 

during this test program but may be due to the extra condensing 

cell in the VP1 sampling train and the lower sampling flow rate, 

both of which allow for additional condensation to occur. A 

regression analysis of the emission data from all four stoves at 

both testing facilities produced the equation: 
VPIC = 0,72(VPIa) + 0.96 (all data) (r2 = 0.98) 

where: VPIC = VP1 emission measurement adjusted to Method 56 

equivalent, g/hr; 

VPIa = Measured VP1 emission value, g/hr. 

r2 = Measure of correlation, perfect = 1.0 

Similar ly deve loped equations for the two locations separately are: 

VPIC = 0.74(VPIa) + 0.91 (RTP) (r2 = 0.97) 

VPIC = 0.72(VPIa) t 0.74 (Crested Butte) (r2 = 0.97) 

Our opinion is that these relationships are the same within the 

precision of the methods. We recommend that the first relationship described 

above be used to convert VP1 emission data to Method 56 equivalent values. 

3 

2. The altitude difference had no apparent effect on emissions for 

these tests. The only data comparison that indicated the 

possibility of a significant altitude effect on emission rate was 

the pair of simulated certification test weighted averages for the 

CC-150 stove. For the simulated certification tests, the CC-150 

produced an average of 15.9 g/hr at the RTP laboratory and 20.1 

g/hr at the Crested Butte facility based on the Method 56 results. 

These two results indicated about a 25 percent increase in 

emissions from the RTP site to the Crested Butte location, which 

is over 8500 ft elevation difference; however, these values fall 

very nearly within the 11.5 to 20.0 g/hr range reported by the 

accredited laboratories. All of the accredited laboratories are 

at 500 ft or lower elevation. The modifications to the loading 

procedure required to accommodate the minimum VP1 sampling time 

may have contributed to the slight increase in emissions from the 

simulated certification tests over the round robin results. 

The weighted average emission rates for the AK-18 simulated certification 

tests showed agreement between the two locations and with results of previous 

certification tests. The AK-18 had weighted average emission rates of 2.0 

g/hr at the RTP laboratory and 2.2 g/hr at the Crested Butte facility. The 

weighted average emission rates ranged from 1.5 to 3.5 g/hr under the EPA 

round robin testing. Clearly, the emission values produced were within the 

expected range for the certification tests indicating no altitude effect. 

(Note: one test run at the RTP laboratory was conducted during an apparent 

failure to achieve catalyst ignition. The results (emission rate = 16.0 g/hr) 

for this test run were omitted from the analysis in order to compare emission 

tests conducted under similar circumstances.) 

3. The emission test results collected during simulated in-home 

operation of the CC-150 at Crested Butte showed up to 7 g/hr 

increase in emissions over the average simulated certification 

test result. The simulated in-home operation of the CC-150 was 
4 

conducted at the Crested Butte facility over at least 7 consecutive days for 

each test. Sampling occurred over periods of low and high burn rates, fuel 

loadings when the door was open, and variations in wood quality. The average 

Method 56 emission rates for the two test runs on the CC-150 during simulated 

in-home operation at Crested Butte were 20.8 and 22.8 g/hr compared to the 

simulated certification test result of 15.9 to 20.1 g/hr. 

One sample with the VP1 sampler was collected for the entire 7-day 

period. Daily Method 56 samples were collected and the seven values were 

averaged for comparison with the VP1 result. The two methods were operated 

simultaneously so that the times of stove operation represented by the two 

methods were identical. The comparable VP1 sampler results corrected 

according to the linear equation described above were 23.7 and 24.0 g/hr. 

4. The emission test results collected during the in-home operation 

of the AK-18 were 7 to 10 g/hr greater than those measured during 

the simulated certification tests. The average Method 56 emission 

rates for the two test runs on the AK-18 during the simulated 

in-home operation were 9.2 and 12.4 g/hr compared with the 

certification test values of 2.0 and 2.2 g/hr. These higher 

emissions during simulated in-home operation indicate periods of 

catalyst bypass for fuel loading and start-up and periods of low 

burn rate which inhibited catalyst ignition. 

The corrected VP1 emission numbers during the same period were 8.8 and 

13.0 g/hr. 

5. The emissions from the Ashley stove were about twice that of the 

Haugh's stove during simulated in-home operation. The average 

emission rates measured with Method 56 for the Ashley and the 

Haugh's stove were 30.7 and 14.4 g/hr, respectively. 

Engineering Science is preparing a final report of the testing on this 

project including CO emission values and paired-train comparisons not included 

in this preliminary summary. I believe that this information will be useful 

to a number of interested parties including the Stationary Source Compliance 

Division, Air Quality Management Division, Standards Development Branch, 

Colorado Department of Health, the Wood Heating Alliance, the Air and Energy 

Engineering Research Laboratory and the many State and local air pollution 

control agencies who are considering woodstove control programs. We should 

distribute this information to these parties. 

Attachment 

cc: Robert Ajax, ESD Rick Colyer, ESD 

William Laxton, TSD Robert Lebens, SSCD 

Ed McCarley, EMB Robert McCrillis, AEERL 

Tom Pace, AQMD Jeff Telander, ESD 
METHOD AND ALTITUDE COMPARISON TESTS 

RTP AN0 CRESTED BUTTE, CO 

STOVE/ LOADING AVG BURN AVG EMIS RATES 

LOCATION CONFIG. RATE M5G VP1 

( kg/hr 1 (why 1 (g/hr ) -c------------------_I__________________---------- 

CC-lSO/RTP 

CC-lSO/RTP 

CC-lSO/RTP 

CC-150/RTP 

CC-lSO/RTP 

CC-lSO/RTP 

CC-lSO/RTP 

CC-lSO/RTP 

CC-lSO/CRSTD BT 

CC-lSO/CRSTO 8T 

CC-lSO/CRSTO BT 

CC-lSO/CRSTD BT 

CC-lSO/CRSTD BT 

CC-lSO/CRSTO BT 

AK-1WRTP 

AK-18/RTP 

AK-18/RTP 

AK-18/RTP 

AK-18/RTP 

AK-18/RTP 

AK-18/RTP 

AK-18/RTP 

AK-18/CRSTD BT 

AK-18/CRSTO 8T 

AK-18/CRSTD BT 

AK-18/CRSTD BT 

AK-18/CRSTO BT 

AK-18/CRSTD BT 

HAUGHWCRSTD BT 

HAUGHS’CRSTD BT 

HAUGHS/CRSTD BT 

ASHLEYXRSTD BT 

ASHLEY/CRSTD BT 

ASHLEY/CRSTO BT 

Note : “CC-150 I# 

“AK-18” 

’ HAUGHS W 

“ASHLEY” 

“RTP” 

M28 0.46 18.01 21.80 

M28 0.78 24 -25 31.40 

M28 0.82 17.66 24.80 

M28 1.17 17.09 24.05 

M28 1.39 16.12 19 -90 

M28 1.49 11.05 13.55 

M28 1.68 7.50 7.05 

M28 1.86 9.68 9.65 

M28 0 -71 28.83 39 -30 

M28 1 .06 13.80 16.50 

M28 1.20 17.36 24.60 

M28 1.27 18.89 23.40 

CORD 0.71 20 -81 31.60 

CORD 0.87 22 “75 32 .OO 

M28 0 -61 16.00 17.15 

M28 0.74 1.18 1.00 

M28 1.04 1.62 1.90 

M28 1.14 2.02 1.95 

M28 1.33 2.23 2.65 

M28 1.51 2.46 3.35 

M28 1.81 3.16 2.70 

M28 1.88 2.38 2.25 

M28 0.66 1.28 0.90 

M28 1.10 2.37 3 -00 

M28 1.15 2 -91 3.80 

M28 1.32 2.79 3.20 

CORD 0.79 9.20 10 -90 

CORD 0.99 12.40 16 -70 

CORD 0.94 14 -54 20.90 

CORD 0.97 14.58 17.60 

CORD 1.13 14.18 16 -70 

CORD 1.45 26.94 37.40 

CORD 1.67 32.70 45.20 

CORD 1.64 32.44 39.60 

- Country Comfort noncatalyst stove; 

- Sweet Home catalyst, modified stove; 

- Haugh’s noncatalyst, low-emitting stove; 

- Ashley noncatalyst stove, Crested Butts; 

- Engineering Science test facility in NC; 

“CRSTO BT * - test facility in Crested Butte, CO; 

“M28” - certification test fuel load, 

Douglas fir dimensional lumber; 

u CORD” - fuel wood typical of that 

used by Crested Butte residents. 

I’ 

- .I. _ “-.-^-..-.-,---_-I_-- w....1__11 ~_I