Efficiency testing

  • Active since 1995, Hearth.com is THE place on the internet for free information and advice about wood stoves, pellet stoves and other energy saving equipment.

    We strive to provide opinions, articles, discussions and history related to Hearth Products and in a more general sense, energy issues.

    We promote the EFFICIENT, RESPONSIBLE, CLEAN and SAFE use of all fuels, whether renewable or fossil.
Nice! Thanks, Todd. Interesting that the fireplace is deemed 16%. I'm sure the number has some accurate basis, but for most who let their fireplaces go cold overnight, before finally closing the damper the next morning or afternoon, I suspect the real net efficiency of their open fireplaces is actually negative.

"It's all about the boundary conditions", as those of us who spend our days running computer simulations like to often remind those receiving our data.
 
I wonder if the Fisher is more efficient because of its radiant quality that transfers more heat? I’ve often wondered if true radiant stove were a little more efficient (heat transfer wise) than convective shielded stoves?
 
I wonder if the Fisher is more efficient because of its radiant quality that transfers more heat? I’ve often wondered if true radiant stove were a little more efficient (heat transfer wise) than convective shielded stoves?
Maybe in some cases, but not all. My Ashford 30's are almost entirely convective, the only radiant surface is the glass in their front doors, but they still have a rated efficiency higher than most radiant stoves on the market.
 
  • Like
Reactions: Todd
OK, Here is the Executive Summary from ECCC. You will find two different parties were involved in testing. PFS TECO and Sherbrooke University. Please read this thoroughly. Keeping in mind methane is a simple VOC and other VOC are complex (multichain), you will read what happens in both VOC reductions (increased methane) and Nox increases with more complete combustion.

If anyone wants the data beyond this Executive Summary, I can see if that too can be posted. I think this is a good read. The old PE performed exceptionally well given it's age and goes to show that regardless of technology, EPA stoves out perform the old smoke dragons.

BKVP
 

Attachments

  • ECCC Summary_ECCC Wood Burning Emissions Study.pdf
    492.6 KB · Views: 96
  • Like
Reactions: ABMax24 and NHWS
Nice! Thanks, Todd. Interesting that the fireplace is deemed 16%. I'm sure the number has some accurate basis, but for most who let their fireplaces go cold overnight, before finally closing the damper the next morning or afternoon, I suspect the real net efficiency of their open fireplaces is actually negative.

"It's all about the boundary conditions", as those of us who spend our days running computer simulations like to often remind those receiving our data

Straight from the test report. I suggest for comparison purposes you only look at actual test reports. And ideally stoves tested to the same method as well.

BKVP

ASHFORD 30.2.JPG
 
  • Like
Reactions: NHWS and Ashful
That test method was flawed and gives a huge advantage rigged to the Blaze King due to the long 45-60 min high burn rate. Any non cat stove burned on high for that long will lower the efficiency because all the heat goes up the stack. The BK thermostat controls this and burns more like a non cat set at a medium setting.

I would also like to know what the age of the cat in the BK was? There’s a big difference between a brand new hyperactive cat and one that has gone through a season or two.

I don’t think you can have one standardized test for different types of stoves. Too many variables and differing burning methods. One thing for sure is dry fuel is paramount for a clean burn.
 
I don’t think you can have one standardized test for different types of stoves. Too many variables and differing burning methods. One thing for sure is dry fuel is paramount for a clean burn.
You need to have one standardized battery of tests applied the same to all stoves, for the simple sake that this is the only way to make a comparative judgement between them. Tests run on high may favor one stove, low another, but they all need to be subjected to the same tests. Furthermore, they need to representative of real-world scenarios, and running one's stove on high for some period of time is something many of us do on a routine basis.
 
  • Like
Reactions: weee123 and ABMax24
OK, Here is the Executive Summary from ECCC. You will find two different parties were involved in testing. PFS TECO and Sherbrooke University. Please read this thoroughly. Keeping in mind methane is a simple VOC and other VOC are complex (multichain), you will read what happens in both VOC reductions (increased methane) and Nox increases with more complete combustion.

If anyone wants the data beyond this Executive Summary, I can see if that too can be posted. I think this is a good read. The old PE performed exceptionally well given it's age and goes to show that regardless of technology, EPA stoves out perform the old smoke dragons.

BKVP

It would have been nice if they would have tested a hybrid stove, I'd like to see how they stack up with regard to NOx and Methane.

Quite frankly the BK NOx emission results were the only surprise I seen in there. I figured the catalyst would have limited NOx production, at least below that of a traditional appliance.

The CO2 values are a little concerning however. A person would think a kg of wood would produce pretty much the same amount of CO2 regardless of appliance type, at least within a few percent of each other anyway.
 
That test method was flawed and gives a huge advantage rigged to the Blaze King due to the long 45-60 min high burn rate. Any non cat stove burned on high for that long will lower the efficiency because all the heat goes up the stack. The BK thermostat controls this and burns more like a non cat set at a medium setting.

I would also like to know what the age of the cat in the BK was? There’s a big difference between a brand new hyperactive cat and one that has gone through a season or two.

I don’t think you can have one standardized test for different types of stoves. Too many variables and differing burning methods. One thing for sure is dry fuel is paramount for a clean burn.
A couple of thoughts. No manufacturers were involved whatsoever. Environment Canada commissioned the study unto themselves. They chose the cordwood method which is an Italian test method. It also mirrors, with slight distortion, the Canterbury method of New Zealand. State and Federal regulators are determined to have a cordwood based method. The method is not flawed. It has been in use for years overseas. It is true the method is vastly different than our M28R crib fuel method.

The cat in the stove and the stove itself was about 5 years in aging. No test method, including both used in the USA, allows a "new" stove. They must be conditioned. The PE32 was in the ownership of the test lab and had been used in other tests and studies.

And, we (industry) did not know this study was taking place until we were told and was to be published.

As to favoring a specific method, are you aware of the significant differences between our 2 methods in the USA? They are extensive and any stove tested to ASTM 3053 has several distinct advantages. It isn't flawed, it is just different. (And too much variability so EPA terminated its use.)

BKVP
 
You need to have one standardized battery of tests applied the same to all stoves, for the simple sake that this is the only way to make a comparative judgement between them. Tests run on high may favor one stove, low another, but they all need to be subjected to the same tests. Furthermore, they need to representative of real-world scenarios, and running one's stove on high for some period of time is something many of us do on a routine basis.
Please, all of you, read my comments in the 2015 NSPS!! I railed against the very idea of tossing aside 40+ years of emissions test data solely because the states wanted cordwood data! Not EPA but the states! So that has proven out to be a "marketing opportunity" in the end. When you have vastly different methods, and different "end points" for when test is concluded, boy can you get some really good numbers to provide your marketing department. And some folks, not knowing these differences and never reading test reports, only push the narrative they understand!

BKVP
 
  • Like
Reactions: Ashful
You need to have one standardized battery of tests applied the same to all stoves, for the simple sake that this is the only way to make a comparative judgement between them. Tests run on high may favor one stove, low another, but they all need to be subjected to the same tests. Furthermore, they need to representative of real-world scenarios, and running one's stove on high for some period of time is something many of us do on a routine basis.
I just don’t think you can make a standardized one size fits all real world test. Different manufactures have different operating instructions for what they think will provide the most efficient burn.

Running on high for some period of time sure but not for an hour. If you did that in a non cat it would cause an over fire situation and when you do turn it down the load will be off gassing all at once continuing the over fire. It’s been preached here many times to follow stove and flue temps when operating your stove not just burn on high for an hour and turn the air down.

If they want some kind of separate idiot proof over fire test fine but when testing for efficiency or particulates they should incorporate manufactures recommendations and instructions.

There would be a lot more stoves on that Fed Tax Credit if they excluded the high burn rate test and averaged the low and medium burn rate where most people burn and manufactures recommended.
 
Please, all of you, read my comments in the 2015 NSPS!! I railed against the very idea of tossing aside 40+ years of emissions test data solely because the states wanted cordwood data! Not EPA but the states! So that has proven out to be a "marketing opportunity" in the end. When you have vastly different methods, and different "end points" for when test is concluded, boy can you get some really good numbers to provide your marketing department. And some folks, not knowing these differences and never reading test reports, only push the narrative they understand!

BKVP
I’m no expert but I’d prefer a cordwood test over a perfectly spaced crib of 2x4 Pine. That’s just seems more real world to me. I also like the idea of the States and manufacturers having more input.

Which testing method did Blaze King use? If both what we’re the differences?
 
Last edited:
  • Like
Reactions: weee123
I agree they need to use standardized testing methods. But I noticed that they adjusted the procedure to fit the bk and Fisher which were the 2 that stood out above the other.
 
  • Like
Reactions: Todd
Here’s my testing method when I become dictator 😂 . Let the manufacture come in and do 3 cordwood tests to get the best particulate and efficiency numbers they can achieve with whatever air setting works best for their stoves. Average them together and let the EPA sign it off if it meets the requirements. Have the manufactures state how they achieve these numbers and give proper directions to prevent over firing and dirty burning in the manual.
 
  • Like
Reactions: begreen
I agree they need to use standardized testing methods. But I noticed that they adjusted the procedure to fit the bk and Fisher which were the 2 that stood out above the other.
By coincidence, or are you accusing a university and a government organization of changing their test method to favor a foreign (to them) manufacturer over their own?
 
By coincidence, or are you accusing a university and a government organization of changing their test method to favor a foreign (to them) manufacturer over their own?
Not purposely no. But it may have favored them inadvertently. If they are using a standard testing procedure and 2 stoves fail under that procedure they should then adjust for all or report that those 2 failed.
 
  • Like
Reactions: Ashful
Another thing I saw (which is more in how it's written than a problem with procedure) is they said they set all stoves to what would be typical of an overnight burn but the bk burnt for 18 hours. Either lowest possible setting or set for overnight burn is absolutely fine. But don't say one thing then not do it.
 
  • Like
Reactions: Todd
I'll admit I'm not going to take the time to read the whole report, but how many runs did they do on each stove? Seems to me that the inherit variability of cordwood would call for several runs, so that you could establish a meaningful average and standard deviation, to flush out said variability.
 
  • Like
Reactions: begreen and Todd
It would have been nice if they would have tested a hybrid stove, I'd like to see how they stack up with regard to NOx and Methane.

Quite frankly the BK NOx emission results were the only surprise I seen in there. I figured the catalyst would have limited NOx production, at least below that of a traditional appliance.

The CO2 values are a little concerning however. A person would think a kg of wood would produce pretty much the same amount of CO2 regardless of appliance type, at least within a few percent of each other anyway.
When I asked each of the scientists involved as to the Nox reading for our unit, and then asked staff from NECAUM/NYSERTA, all confirmed that the Nox reading were indicative of greater efficiency.

BKVP
 
I just don’t think you can make a standardized one size fits all real world test. Different manufactures have different operating instructions for what they think will provide the most efficient burn.

Running on high for some period of time sure but not for an hour. If you did that in a non cat it would cause an over fire situation and when you do turn it down the load will be off gassing all at once continuing the over fire. It’s been preached here many times to follow stove and flue temps when operating your stove not just burn on high for an hour and turn the air down.

If they want some kind of separate idiot proof over fire test fine but when testing for efficiency or particulates they should incorporate manufactures recommendations and instructions.

There would be a lot more stoves on that Fed Tax Credit if they excluded the high burn rate test and averaged the low and medium burn rate where most people burn and manufactures recommended.
Back in 2008, industry convinced EPA to help approach the IRS and revise tax code legislation by not using HHV efficiency but rather LHV. In 2009 the IRS was less than pleased that:

1) Nearly 100% of wood heaters qualified (which is NOT the intent but rather reward those consumers that elect to spend money on more efficient models)
2) The massive hit they took in IRS tax income as a result of #1.

Then in 2009, the IRS lowered the credit to $350.00. The legislators working on this 25C credit were adamant that only the top "x"% should qualify. That is why the list is refined.

We also advocate for consumers to burn their stoves on high for 60+ minutes at a frequency that avoids the formulation of large amounts of creosote in the firebox.

When you introduce variable methods to accommodate design differences, you also introduce greater variability AND make it harder for buyers to compare one stove to another.

BKVP
 
  • Like
Reactions: Todd
Here’s my testing method when I become dictator 😂 . Let the manufacture come in and do 3 cordwood tests to get the best particulate and efficiency numbers they can achieve with whatever air setting works best for their stoves. Average them together and let the EPA sign it off if it meets the requirements. Have the manufactures state how they achieve these numbers and give proper directions to prevent over firing and dirty burning in the manual.
When the NSPS opens soon for promulgation, I will be looking for your data-based recommendations. (EPA comments must be based upon and supported by test data). But I do like the suggestion of fewer test runs. Currently, a method called IDC (integrated duty cycle) is based upon some of your comments. They must reading your mind!

BKVP
 
  • Like
Reactions: Todd
I’m no expert but I’d prefer a cordwood test over a perfectly spaced crib of 2x4 Pine. That’s just seems more real world to me. I also like the idea of the States and manufacturers having more input.

Which testing method did Blaze King use? If both what we’re the differences?
We were concerned about rumblings at EPA that a certain mfg had "manipulated" the ASTM 3053 to get better results. Looking and comparing Owner manuals and test reports showed great liberties were taken.

We had just tested and recertification all units for the 2020 requirements in 2014. Then the rule came out in 2015 with a change in M28R, that required a 1st hour filter pull. We had to retest 100% of our units only 7 months later!!

If you read my comments of record for the 2015 NSPS, I provided data to support the continuation of M28R with one additional run using cordwood from a species determined by EPA. The cordwood run would permit state agencies to see how stoves performed at different burn rates. However, the result of the cordwood run would not be permitted in your gr/h test results. It would simply provide cordwood data...and consumers would still be able to compare the M28R results from each stove, WHICH HAS THE LEAST AMOUNT OF VARIABILITY.

Today, had they pursued this idea, the would have data on 178 different models instead of the 77 units that used the ASTM 3053 method, which all that data was a waste and cost industry about $2.5M in test fees.

BKVP
 
  • Like
Reactions: Todd
Sounds messed up and complicated. Maybe too many unelected bureaucrats involved. Remember the good old days where they had every stove listed at a generic efficiency? What was it 63% for non cat 72% for cat stove?
 
The problem is similar to automobile emissions testing. The test works ok for a standard design, but falls apart when new or alternative technology is introduced. Chevy Volt owners ran into this because the engine is a generator, not the motive powerplant. You can't rev the engine up to X rpm for the test. And it will likely fail if the vehicle arrives on electric power because the motor is stone cold.