8431 Murphy Drive 

Middleton, WI 53562 

Telephone: 608 836 4400 

Facsimile: 608 831 9279 

www.intertek-etlsemko.com 

Intertek Testing Services NA, Inc. 8431 Murphy Drive, Middleton, WI 53652 

14 December 2011 

Dr. Tom Butcher 

Brookhaven National Laboratory 

Upton, NY 11973 

RE: NYSERDA Report No. 11-17 “Review of EPA Method 28 Outdoor Wood 

Hydronic Heater Test Results” 

Dear Dr. Butcher: 

As you know Intertek was one of the labs that conducted tests that were the 

subject to the NYSERDA report. As this report makes many statements and 

assertions that appear very critical of laboratories involved in regard to 

competence and quality of the testing, we find it potentially very damaging to 

Intertek’s reputation. Whether or not it was intended, this report is being 

regarded as an attack on the competence and credibility of independent 

laboratories generally. We have, therefore, reviewed the report in detail and are 

submitting the attached response. 

Aside from the specific comments in our review, our main concern is that the 

report implies that the issues raised are equally applicable to all laboratories 

involved. We strongly feel that this is inappropriate. We believe that all tests and 

reports submitted by Intertek under the EPA OWHH partnership program 

procedures were in compliance with the requirements and represent the highest 

level of quality. 

There is, of course, no doubt that the EPA M28 OWHH procedures themselves 

were deficient which did result in laboratories being required to report results of 

less accuracy than was assumed. However, Intertek consistently brought these 

issues to EPA’s attention and implemented procedures to improve the accuracy of 

our results. 
Intertek Testing Services NA, Inc. 8431 Murphy Drive, Middleton, WI 53562

It should also be pointed out that the suspect test results (high efficiencies) that 

led to this process were not only issued by the lab, but were accepted by the 

manufacturers and reviewed and accepted by EPA apparently without any 

recognition of what should have been an obvious problem. 

Please accept our comments as a technical review and critique of the report itself. 

Sincerely, 

Rick Curkeet, PE 

Chief Engineer – Hearth Products 

cc: Amanda Aldridge - EPA 

 Gil Wood - EPA 

 Lisa Rector – NESCAUM 

 Louis Fontaine – Maine, DEP 

 Phil Etter – Vermont, DEC 

 Marc Cohen – Massachusetts, DEP 

 Randy Orr and John Barnes – NYSDEC 

 Robert Lebens - WESTAR 
Page 1 of 10 

Intertek Review of NYSERDA Report No. 11-17 “Review of EPA Method 28 

Outdoor Wood Hydronic Heater Test Results”, September 2011 

12/14/2011 

The subject report is described as a review of the 23 test reports submitted for the 

wood fired hydronic heaters qualified by EPA under phase II of the Voluntary 

Hydronic Heater Program. Intertek has reviewed this report and has the following 

comments. 

It should be understood that the test method – EPA Method 28 OWHH – was not a 

consensus standard. It was taken, nearly verbatim, from draft 4 of a test method 

that was under development by ASTM Subcommittee E06.54 in early 2006. The 

eventual ASTM standard (E2618) that was published was based on draft 12 of this 

procedure. There were, thus, many deficiencies in the EPA method. The method 

was also essentially new and had not been applied or validated to any significant 

extent before it was implemented. It was largely the demands of NESCAUM and 

North East States air quality regulators – the same interest group that sponsored the 

NYSERDA Review - that demanded EPA establish the program quickly and without 

any attempt to validate the test method. It should thus not be surprising that some 

results of questionable accuracy have been produced. 

Since the authors have not included the actual data in the report, it is impossible to 

verify their statements. It is our understanding that the laboratories provided all the 

data and the details of all calculations. NYSERDA has not provided in this report 

any means for us to check of verify their assertions. However, as Intertek tested 11 

of the appliances involved we do have detailed and complete knowledge of this 

portion of the data set. We have reviewed this data in detail and stand behind it 

100%. That is not to say that we do not recognize that some of the results have a 

large inherent error. In fact, Intertek objected to the requirement for measuring 

heat output on the supply-side of the system because we had determined that the 

error was too large for a reliable measurement. 

The primary issue that led to this review was the issuance of reports and subsequent 

publication on EPA’s “Burn Wise” web site listing of qualified hydronic heaters 

which showed heating efficiencies higher than is theoretically possible for 

appliances that do not incorporate latent heat recovery through water 

condensation. It has been demonstrated that this theoretical upper limit is about 

85% based on the Higher Heating Value of the fuel. However, at least 6 products 

were listed with efficiencies reported at 88% to 99%. We note here that none of 

these reports was issued by Intertek. 

The NYSERDA report fails to postulate or identify a specific cause for the erroneous 

results. Instead, it apparently assumes that all tests were conducted in compliance 

with the test method and thus focuses on potential for error within the narrow 

confines of testing in compliance with the method. While we do agree with a 
Page 2 of 10 

number of the recommendations in this report - in fact many originated as our 

recommendations as far back as the initial method development – none appear to 

be sufficient to explain the very high efficiency results at issue. 

In addition, we find many of the statements and assertions in this report to be 

unsupported by the facts. The following are just a few examples. 

1) The report states that 14 of the 23 units reported higher efficiencies than 

determined by the stack loss method. But 11 of the 23 were tested by Intertek and 

in only 2 of the 44 individual test runs involved did we see delivered efficiencies 

based on the load-side measurements that were slightly higher than the B415.1 

calculated stack loss efficiencies. None of the Intertek weighted average or 8-hour 

efficiencies where higher. In the two individual test runs where there was an issue 

with this, error in the B415.1 stack loss values could easily explain the difference. 

The accuracy of stack loss methods is unknown and the approach is least reliable for 

appliances that cycle frequently in combustion air supply and burn rate. In both 

cases the delivered efficiencies we reported where under 76% well under the 

theoretical upper bound for non-condensing appliances. Apparently, however, 

NYSERDA used their own stack loss calculation procedure, which appears very 

crude. Not using the CSA B415.l procedure is hard to understand, as it is a 

published, consensus-based method. They did not provide any estimate of the 

uncertainty of their approach, but it is surely large enough to put any conclusions 

about the delivered efficiency into doubt where the difference is less than 5 to 

10%. Our estimate of the uncertainty in the CSA B415.1-2010 method around +/- 

3%. The method used by NYSERDA (BNL Calculation Procedure) is based only on 

average CO2 concentration and average stack temperature and must certainly have 

a much larger uncertainty. The NYSERDA report states that the method used is 

"reasonably accurate under steady-state conditions". That may be true (although 

no data are provided to support this position), but these appliances never operate 

under steady-state conditions even in category IV test. Burn rate, fuel composition, 

heat release rate, flue gas temperatures, and flue gas composition change 

continuously. Many of these units cycle at least a few times even at the high output 

rate. 

Based on the efficiency values originally published on the EPA Burn Wise website, 

we believe 6 appliances were listed with efficiencies that are theoretically 

impossible, and 2 more with efficiencies that should be considered suspect. Thus, 

15 of the 23 models listed had efficiency values that were plausible. 

2) The report does not recognize that the test method includes a bias toward higher 

than actual delivered efficiency results. This is due to the requirement in the 

method that during the pre-burn cycle the coal bed is to be "fully charcoalized". 

This is easy to accomplish by burning wood with small cross sections for the preburn. However, at the end of a test run the actual test fuel load is often not "fully 

charcoalized". The fuel that remains at the end of a test run can have significantly 

lower energy content (for the same weight) than the coal bed that is present at the 
Page 3 of 10 

start of the test. Thus, the heat content of the fuel actually burned during a run can 

be significantly higher than the input calculated. This tends to bias the efficiency 

upwards by as much as 5 to 7 percentage points by our estimates. The stack loss 

method does not have this bias to the same degree. It measures the losses up the 

chimney and subtracts them from the calculated input. Therefore, the actual input 

being different than the assumed input has a smaller impact on the results. 

The report also fails to note that at least 3 of the high efficiency results are for pellet 

burning appliances where the fuel input, moisture content and coal bed 

charcoalization should not be factors. A pellet appliance test that results in 

unrealistically high efficiency indicates a significant error in the output 

measurement, an error in the determination of the heating value of the pellets or an 

error in the measurement of the fuel mass consumed or a combination of these. 

3) The paper makes many recommendations which are not supported by any 

evidence or analysis. For example, it recommends a 15 second reading interval even 

though the revised EPA Method WHH already requires 1 minute intervals – 10 times 

more often that was required by the original method. They provide no supporting 

evidence other than stating that "a ten minute period may not adequately represent 

peaks and valleys of the cycle”. Our analysis of 1 minute data processed at 2, 5 and 

10 minute intervals shows very little difference in any of the key outputs of the 

calculations. Peaks and valleys certainly are evident in the supply-side outlet and 

return water temperatures and flue gas composition data, but the key 

measurements for determining heat output on the load-side and the particulate 

emissions are typically very steady. This is because the load-side heat draw is 

maintained as close as possible to the target output rate. The water temperature 

and flow rate provided to the heat exchanger is thus nearly constant and 

temperature exiting the heat exchanger is therefore also fairly constant. The 

dilution tunnel flow and particulate sampling rates are maintained at nearly 

constant levels as required by the ASTM E2515 method. Therefore, the key 

measurements – heat output and total particulates – rely on data that is not subject 

to substantial “peaks and valleys” during the test runs and higher reading 

frequency adds no significant precision. 

4) Intertek knew from the start that the supply-side measurements had a substantial 

accuracy problem and advocated the load-side measurements from the beginning. 

The ASTM E2618 method has always required this. In fact, in some of our tests we 

saw clear issues with the accuracy of the supply-side measurements and obtained 

agreement from EPA staff that we should report the load-side results. This might 

account for some of the "incomplete" data as we did not include the erroneous 

data for affected test programs. 

In addition a detailed measurement uncertainty analysis conducted by Intertek 

demonstrated that the uncertainty of supply-side measurements could be as high as 
Page 4 of 10 

± 22% for low output tests even if all measurements met the specified accuracy and 

are more likely 2 to 3 times larger under the actual test conditions. 

5) The simplest conclusion one could draw from a review of all the data is that the 

most obviously erroneous results all originated from a single source. This is a fact 

that is entirely absent from discussion in the report. An objective review of the data 

could not fail to uncover this reality. The paper also fails to postulate a probable 

cause for the largest deviations - i.e. 85 to 99%+ efficiencies. Could it not be that 

the raw data was simply wrong? Where any of the suspect results related to 

appliances and tests that deviated from those that the procedure applies to such as 

appliances connected to large mass heat storage systems? Whether it’s a 

temperature difference measurement issue, a water flow measurement issue, a 

wood weight and moisture measurement issue or a combination of these, 

something must have been wrong. No amount of looking at bad data will identify 

why the data is bad. 

6) Table 1 on page 8 is from a test program that Intertek conducted. But the data 

in the table does not match up with the data submitted. Some of the differences 

are minor, but others are significant. Line 29 on this table (APD) purports to be the 

“Actual difference between boiler-side and load-side output” in percent. But the 

numbers – 200+ % - are clearly not correct. Neither are they simply a case of a 

misplaced decimal point. The entries for dTload and dTsupply (lines 23 and 24) do 

not include data for the category II, III and IV test runs although this data was 

submitted. The “Output Analysis” data shown in Table 2 on page 9 do not match 

the data submitted. It is difficult to take seriously criticism of labs not submitting 

complete or accurate data in a report where such obvious errors and omissions are 

present. These tables make it appear that the data submitted was incomplete when 

it was not. (See Appendix A for a comparison of the data in the report and the data 

submitted by Intertek.) 

7) The report mischaracterizes the potential error associated with the temperature 

difference measurements. The test method does require that the temperature 

difference measurement be made with instruments that can measure temperature 

difference to ± 0.5 oF. However, this can only be demonstrated by calibration 

through measurement of a reference with “known” temperatures that are more 

accurately measured. This is typically done using water baths held at stable 

temperatures and measured with certified glass thermometers or precision RTD’s. 

Thermocouples can meet this specification, but when installed in a dynamic system 

to measure temperatures of flowing water, additional uncertainties are introduced 

that cannot be readily quantified. The fact is that we are measuring flowing water 

with a device that has thermal mass, a lag time, measures a stream which is often 

non-uniform and changing in temperature, etc. So, while the measurement of 

temperature difference under static calibration meets the ± 0.5 oF specification, in 

the dynamic system a significantly larger error is likely. There is no way of knowing 

how precise the temperature difference measurement actually is. There is no 

calibration process that can directly verify the accuracy of the temperature 
Page 5 of 10 

difference measurement as applied in the test as doing so would require an 

independent measurement of the temperature difference with a known accuracy 

significantly better than that of the instrumentation being calibrated. But if we had 

such a system available, we’d just use it instead of the thermocouples. Of course, 

any other measurement device would suffer from the same uncertainty issues in the 

actual dynamic application. So there is something of a “Catch-22” in the test 

method. That is, the method contains a required measurement precision which 

cannot be readily verified. 

We believe that the thermopile system we have used for some time now has 

substantially reduced this error. Comparisons of the temperature differences 

measured by a thermopile to those measured by single thermocouples typically 

show a difference of several degrees F. It is quite likely that labs could have used 

thermocouples that met the accuracy requirements based on the calibration 

requirement of the standard and still have had much larger errors in temperature 

difference measurements while conducting actual tests. While these issues are 

moot for the future, as the revised method requires the use of thermopiles, it is still 

worth noting that this issue is far more significant for measurements of output 

made on the supply-side of the system where the temperature difference can be 

only a few degrees F. The actual error for measurements made on the load-side of 

the system has a much smaller impact on the accuracy of the results due to the 

much larger actual temperature differences. And, of course, the revised method 

relies on load-side measurements. 

8) The authors appear to have misinterpreted the heat output category 

requirements of the M28 OWHH procedure. The procedure bases heat output test 

loads on the “manufacturer’s rated output capacity”. As long as the output 

achieved in the category IV test is within 10% of the rated capacity, the test load 

outputs are based on the rated capacity, not the measured category IV output. 

Thus, if the appliance is rated at 100,000 Btu/hr, the category IV test result needs to 

be between 90,000 and 110,000 Btu/hr. The upper limits for the category I, II and II 

tests are then 15,000, 24,000 and 50,000 Btu/hr respectively. The NYSERDA 

reports indicate the authors based their conclusions regarding tests being out of the 

specified range on the percentage of the measured category IV test output rather 

than the manufacturer’s rated output. 

It should also be noted that the difference in load-side and supply-side heat output 

measurement accuracy can result in a test being within the specified category based 

on one measure, but outside the category on the other. Labs have been faced with 

the difficulty of trying to operate at output rates that would be in the required 

category using the supply-side inaccurate measurements when they know the 

accurate load-side measurement is outside the required category. 
Page 6 of 10 

OTHER COMMENTS 

Intertek is surprised to find considerable discussion of issues that are unrelated and 

irrelevant to the issue of EPA M28 OWHH test results. These include nearly 9 pages 

devoted to a discussion of appropriate appliance sizing and weighting factors used 

to determine average performance and recommendations on technology 

improvements. These issues are of no consequence in the evaluation of the 

accuracy of test results submitted based on the original EPA M28 OWHH procedure. 

However, since the authors saw fit to discuss these issues, Intertek will take this 

opportunity to respond to a few of the points discussed. 

APPLIANCE SIZING 

In section 5.2 the authors go to considerable length to justify a heavy weighting on 

the low output test data. For example they state that the average design heat load 

for a US home is 65,000 Btu/hr while the average output capacity of the units in the 

voluntary program is 175,000 Btu/hr. From this they deduce that hydronic heaters 

are oversized by a “sizing factor” of 2.7 to 8.8. This is complete hyperbole. 

Hydronic heaters have been primarily marketed in the northern mid-west and New 

England area to farmers and home owners with much higher than average heating 

requirements. The range of rated outputs of appliances tested by Intertek is 44,700 

to 217,000 Btu/hr with 5 of 11around 100,000 Btu/hr or less. A simple check of 

major gas and oil boiler manufacturers product lists indicates all offer residential 

boilers in output ranges from 40,000 to over 300,000 Btu/hr. European wood fire 

boilers are offered in sizes typically from 20 to 80 kW (68,000 to 275,000 Btu/hr). 

While we understand the concern regarding appliance sizing discussed in 5.1 and 

5.2, this has nothing to do with the process or accuracy of rating the appliances. Of 

course it is inappropriate to install a 175,000 Btu/hr appliance in a building with a 

65,000 Btu/hr design heat demand. But it’s perfectly fine for a building with a 

175,000 Btu/hr requirement. M28 WHH has nothing to do with consumers buying 

appropriately sized appliances. 

“Sizing factor” is not term used in the HVAC industry that we are aware of. In fact, 

HVAC Handbooks such as the ASHRAE Fundamentals devote many chapters to 

estimating heating loads and selection of properly sized heating equipment. In our 

experience, professional HVAC contractors are well aware of the appropriate 

appliance sizing practices. 

We would also note that anyone with a design heat load of 55,000 Btu/hr, as used 

in the example in the paper, has a very small heat demand and likely a small 

modern home. Not likely to be someone who would invest $8,000-12,000 in a 

wood fired hydronic heating system. The reality is these units are attractive to 

consumers who do have large heat demands – rural, old, large, poorly insulated 
Page 7 of 10 

houses, small commercial establishments, etc. If heating costs are $1000/mo or 

more using traditional fossil fuel heating and there is a ready cheap source of wood, 

these units can actually pay back the investment. 

WEIGHTING SCHEME 

We would suggest that the issue of weighting should start with the assumption that 

consumers should buy appliances that are correctly sized for their need. This would 

eliminate columns labeled 2 and higher in tables 7 and 8. This would then indicate 

that, if anything, the SR proposed weightings are more severe than the Syracuse Bin 

Data profile indicates (heavier weighting on the Category I and II outputs). Column 

1 (i.e. correctly sized appliance) of table 8 indicates that the current M28 WHH 

weighting on category I is way too high (0.437 vs 0.077) and that the heaviest 

weighting should actually be on the category III results. 

We understand that many people seem to think that these units are sometimes 

used year round since they are often installed with an indirect domestic hot water 

(DHW) heating function. This makes sense during the heating season as the DHW 

load can be easily supplied without a noticeable impact of the building heating. But, 

this led to the idea that the appliances are operated year round but only to heat 

DHW in the summer. This is a highly questionable position. The typical residential 

water heating demand is around 30,000 Btu per day. Most of this demand takes 

place during relatively short time frames in the morning and evening. It is doubtful 

that any of the cordwood fired boilers under discussion would sustain a fire given 

these low load conditions. In any case, such a low demand when burning full loads 

of wood would result in efficiencies so low that the waste of fuel would be very 

obvious. Even heating water with the most expensive traditional fuels which 

operate at 70% or higher efficiencies would be far less expensive than heating with 

wood where efficiencies would probably be less than 10%. 

e.g. Suppose a unit is rated at 100,000 Btu/hr and is set-up to operate at demands 

as low as 10,000 Btu/hr. When there is no demand the appliance will continue to 

produce 10,000 Btu/hr of heat which will be wasted. During a 24 hour period the 

appliance would thus produce 240,000 Btus of which 30,000 could be used for 

DHW. 210,000 Btus would be unusable. So, only 12.5% of the heat produced 

could be used for DHW. It makes no sense to heat domestic hot water this way. 

TECHNOLOGY PROMOTION

The authors take the opportunity to promote the partial heat storage approach as a 

"proven" method of improving efficiency and emissions (6.5). But there is no hard 

evidence for this stance either. What is missing in an understanding of the basic 

flaw in the concept. It is true that most buildings require less than 25% of a 

properly sized appliance’s output capacity much of the time. But adding heat 

storage means that after most fuel loads are burned, the storage will provide heat 

for many hours after the fuel has been consumed and a new fire will need to be 
Page 8 of 10 

started for nearly every operating cycle. However, emissions produced during 

ignition of a fuel load without the benefit of a hot coal bed have rarely been 

measured. Virtually all existing data is from tests conducted by loading fresh fuel 

onto a large hot coal bed which generates very quick ignition and initiation of 

secondary combustion. 

Intertek has done several tests of appliances that have very low emissions ratings 

per the EN 303-5 method using the "cold-start" procedure proposed for the ASTM 

standard. The emissions produced while the new fuel load is being ignited are quite 

heavy and last for anywhere from 1/2 to 1 hour. Emissions rates can be over 1.5 

lb/mmBtu output, and efficiency under 50%. In short, there is a trade off here – 

reducing cycling comes at the price of many more cold starts. If there is not a well 

established hot coal bed on the grate when these appliances are loaded with fuel, it 

is doubtful they will perform nearly as well as expected. In our experience, they 

actually do much better without heat storage at low output rates where they cycle 

on and off and are operated with fuel loaded on a substantial hot coal bed. 

NYSERDA in their up-coming research test program should conduct emissions tests 

with an EN 303-5 appliance with heat storage connected using cold starts, to 

generate data to address this important issue. 

In wood burning appliance emissions testing we have always ignored the issue of 

"cold-starts" based on the idea that users try to keep their wood stoves or boilers 

running for many days. Thus, there has always been a demand for appliances that 

will "hold a fire over night". WHH's typically have large fireboxes so that refueling 

on an existing coal bed can be done at intervals of 12 to 24 hours or more. As a 

result, we have produced virtually no data indicating how cold starts affect 

emissions/efficiency performance. Those of us who have done hundreds of tests 

know that we tend to see a lot of smoke when we start appliances up to establish 

the coal bed required for the test runs. But if a fire only has to be started 

infrequently, it's probably not a very significant issue. The EN 303-5 standard also 

ignores the start-up issue, but then effectively requires the use of heat accumulators 

which guarantees that most fuelings will be cold starts. The disconnect between 

lab testing and consumer operation should be obvious. But NYSERDA has heavily 

endorsed the heat storage concept based on European test data and is actively 

promoting this technology. This seems to bring their objectivity into question when 

it comes to making recommendations such as those contained in the report. 

It should be noted that this is not an issue for full storage appliances that meet 

emissions requirements under Appendix X1 of ASTM E2618 which evaluates the 

appliance under cold-start operation. 
Page 9 of 10 

Appendix A. 

Tables 1 & 2 As Reported by NYSERDA 

 

Category

1. Inputs symbol units I II III IV Description of measurement

Ts F 175 191.3 220.2 377 Average stack gas temperature

EA % 117 200 160 66 Excess air 

Tsup F 166.9 163.5 167.2 153.7 Boiler supply temperature

Tret F 164.52 156.1 157.11 133.83 Boiler return temperature

Tcw F 83.96 69.17 63.79 57.52 Cold water

Tcwout F 158.08 144.45 146.7 131.56 Cooling water out of heat exchanger

Vfls gpm 0.277 0.541 0.659 2.199 load side water flow

Vfss gpm 4.18 6.85 8.08 8.61 supply side water flow

mp ln/MMBtu 0.29 0.23 0.21 0.05 particulate emissions (supply side)

Eff % 42 78.2 79.4 73 efficiency based on supply side

MC % 19.37 21.13 21.7 21.09 moisture content

dTload F 83.18 load side delta-T

dtSupply F 5.2495 Supply side delta-T

dTbs F 5.25 7.4 10.09 19.87 Average boiler side delta-T

2. Calculatrions MPEbs % 11.52 8.76 6.96 4.52 Max error in output (boiler side)

MPEIs % 1.1 1.16 1.1 1.18 Max error in output (load side)

MPD % 12.63 9.92 8.06 5.69 Max difference between boiler side and load side output

APD % 214.69 208.28 206.76 201.37 Actual difference between boiler side and load side output

EffComb % 84.24 81.28 80.84 78.29 Combution efficiency 

3. Evaluations 5.25 7.4 10.09 High Supply Side Error

Difference between supply side and load side output out of range

-1.44 Low combustion efficiency

Moisture content out of range

133.83 Low T return 

4. Results Average

original load side Comb Eff

Annual Efficiency 62.5 51.3 82.3

Annual PM lb/MMBtu Output 0.242 0.286

Cat IV Efficiency 73 70.8 78.3

I II III IV

5. Output Analysis 10701 24772 39832 84065 Supply Side Output Btu/hr

10212 20330 27309 81065 Load Side Output Btu/hr

25479 31677 50165 115157 Input Btu/hr

12.7 29.5 47.4 100 Cat output as % of Cat IV - Supply Side

12.5 24.9 33.5 100 Cat output as % of Cat IV - Load Side

40.1 64.2 54.4 70.8 Efficiency based on load side

<15 16 to 24 25 to 50 Rated Cat % Output Range from M28

6. Correction for Mass, dT

-4.93 -1.3122 0.3507 -15.2348 Unit Temp Change F 561.1 Capacity Btu/F

1150 704 541 235 duration (min)

10557 24709 39853 81882 Adj Supply Side Output Btu/hr

10068 20267 27331 79319 Adj Load Side Output Btu/hr

12.9 30.2 48.7 100 Cat output as % of Cat IV - Supply Side

12.7 25.6 34.5 100 Cat output as % of Cat IV - Load Side

39.5 68777.3 57682.3 79318.7 Efficiency based on load side

-1.4 -0.3 0.1 -2.7 % change in load side output due to mass,dt correction
Page 10 of 10 

Table 1 & 2 Revised to include the data as submitted by Intertek 

Intertek Note: It was recognized during this program that the category II and III tests showed a 

large difference between the load and supply-side results. We did propose to report the results 

based on the load-side data which we considered to be accurate. However, since the test 

method required reporting based on the supply-side data, the report was issued on this basis to 

comply with EPA requirements. 

ACTUAL DATA SUBMITTED

Green highlighted data within 2% of NYSERDA Report

Red highlighted data more than 2% different than NYSERDA

Category

1 Inputs symbol units I II III IV Description of measurement

Ts F 174.37 191.61 218.38 379.39 Average stack gas temperature

EA % 100 222 204 66 Excess air (B415)

Tsup F 166.9 164.55 167.2 153.7 Boiler supply temperature

Tret F 164.52 155.99 157.11 133.83 Boiler return temperature

Tcw F 83.96 69.17 63.79 57.52 Cold water

Tcwout F 158.08 144.45 150.48 131.56 Cooling water out of heat exchanger

Vfls gpm 0.277 0.461 0.603 2.199 load side water flow

Vfss gpm 4.180 6.850 8.080 8.610 supply side water flow

mp lb/MMBtu 0.289 0.233 0.21 0.048 particulate emissions (supply side)

Eff % 42 78.2 79.4 73 efficiency based on supply side

MC % 19.37 21.13 21.7 21.09 moisture content

dTload F 83.18 75.28 86.69 74.05 load side delta-T

dtSupply F 5.2495 8.561 10.05 19.87 Supply side delta-T

dTbs F 5.25 8.561 10.05 19.87 Average boiler side delta-T

2. Calculatrions MPEbs % 11.52 7.84 6.98 4.52 Max error in output (boiler side)

MPEIs % 1.10 1.16 1.08 1.18 Max error in output (load side)

MPD % 12.63 9.00 8.05 5.69 Max difference between boiler side and load side output

APD % -7.14 39.52 34.04 2.81 Actual difference between boiler side and load side output

EffComb % 74.41 73.88 72.12 78.37 Combution efficiency (B415)

3. Evaluations 5.25 8.561 10.05 19.87 High Supply Side Error

-6.7% 65.3% 51.6% 2.9% Difference between supply side and load side output out of range

29.5 26.4 19.4 5.5 Low combustion efficiency

19.37 21.13 21.7 21.09 Moisture content out of range

164.52 155.99 157.11 133.83 Low T return (<125 F)

4. Results Average

original load side Comb Eff

Annual Efficiency 62.5 49.1 73.9

Annual PM lb/MMBtu Output 0.242 0.3

Cat IV Efficiency 73 70.8 78.3

I II III IV

5. Output Analysis 10,698 28,695 40,137 85,151 Supply Side Output Btu/hr

11,452 17,381 26,465 82,822 Load Side Output Btu/hr

25,479 36,631 50,165 113,709 Input Btu/hr

12.7 29.5 47.4 100 Cat output as % of Cat IV - Supply Side

12.5 24.9 33.5 100 Cat output as % of Cat IV - Load Side

44.9 47.4 52.8 72.8 Efficiency based on load side

<15 16 to 24 25 to 50 Rated Cat % Output Range from M28

6. Correction for Mass, dT

-4.93 -1.3122 0.3507 -15.2348 Unit Temp Change F 561.1 Capacity Btu/F

1150 704 541 235 duration (min)

10,554 28,632 40,159 82,968 Adj Supply Side Output Btu/hr

11,308 17,318 26,487 80,639 Adj Load Side Output Btu/hr

12.72 34.51 48.40 100 Cat output as % of Cat IV- Supply Side

14.02 21.48 32.85 100 Cat output as % of Cat IV - Load Side

44.38 47.28 52.80 70.92 Efficiency based on load side

-1.26 -0.36 0.08 -2.64 % change in load side output due to mass,dt correction