Are EPA numbers complete BS?

[BrotherBart]

One more time. The EPA does not require testing for efficiency. They don't care if it heats your house or not. Just that it ain't smoking. They offer manufacturers the option of them publishing "default" values for cat, non-cat and pellet stoves that were developed in 1987 or they can pay ten to twenty grand to have the stoves tested for actual BTU output and efficiency. A very few stove makers have opted to have actual values tested and published.

There are three numbers usually available. The low burn EPA "default" number. The high burn EPA "default" number. The "max" number that manufacturers publish stoking the stove like a freight train slamming wood in it constantly and firing the crap out of it.



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[FionaD]

I love you, Brother Bart !

 

[velvetfoot]

Can one believe the smoke numbers?

 

[BrotherBart]

The particulate emissions numbers? Yep. Well, except for a few years ago when an independent lab manager got caught taking money under the table to fudge them. But that got corrected.

 

[rideau]

Having gone from a 73,000 BTU stove to a 61,000 BTU stove that puts out 4x the heat and burns 4x as long, I'd say yeah, EPA numbers are useless.

Did the EPA list the Lopi at 73,000 or did Lopi? I didn't think any tested stove had tested that high before the PH?

 

[spirilis]

Curious about a detail - EPA efficiency numbers, is that % of potential BTU extracted from wood (whether it enters your house or goes up the chimney being irrelevant), or % of potential BTU actually delivered to the house?
(I suspect the former, as that is most closely related to smoke emissions, but I'm curious what the latter number would be...)

 

[bholler]

The heat output numbers are not from the epa they are from independant testing facilities the epa only cares about emissions

 

[rideau]

I don't think the EPA testing is wrong, I just think you have to be knowledgeable about the stove you are thinking of buying and what it is designed to do.

BK designs stoves to burn long and low. They can be burned short and high, and the manual from the company tells you to get the high output that they claim possible (significantly higher than the EPA listing), that you have to reload quite frequently. However, the stove will burn for many, many hours on a full load at 9,000 or slightly higher output.

Woodstock stoves are designed to provide high heat for as long as possible for a cold climate, with the ability to also heat during the shoulder season. So they are designed to run for 8 - 12 hour easy reloads, depending on the stove, during high heat output. They can be run with minimal heat output: 12,000 BTU per hour. But that is not going to happen if you load a Woodstock to the gills, as a general rule. You will get a period of at least moderate heat output from a fully loaded Woodstock. To get truly low heat output throughout a burn from a Woodstock, you use a small load of wood. It will burn for a long time on a little wood and produce low heat.

If I load 60 pounds into my Woodstock, I can probably get about 360,000 BTUs out of the load. For a 12 hour burn that averages about 30,000 BTU's per hour. Because of the mass of the stove and the slow radiation from soapstone, I do get amazingly close to that output until the very end of the coal burning stage. I can easily get a longer burn, with very good heat output per hour, or a shorter burn with massive heat output. What I cannot do is get a 30 hour burn with 12,000 BTU's per hour.

So, BTU output isn't the entire story. But the potential and how it is achieved with each stove is important to know. I wish all stove dealers were as transparent as Woodstock and BK about how they expect you to burn their stoves, and what their stoves are reasonably capable of doing. It would make things easier for consumers.

It is a good thing that the stoves from different manufacturers perform differently. It provides almost all of us with the ability to purchase a stove that works for our particular location and needs. Which is why so many of us are so satisfied with very different stoves.

 

[DougA]

I don't think the ULC testing is wrong

As stated, EPA does not do BTU testing, they rely on the numbers supplied by others.
I think you are correct that BTU is not the entire story but as in cars, people use the EPA numbers to compare one mfg against another. Using them that way will be inaccurate, at least for wood stoves.

rideau - BTW, as a separate issue, I'd appreciate knowing if your Woodstock stove is ULC certified. If not, how did you get it past the WETT inspection or did you? PM me if you want. I called Woodstock to put my $$ down on a stove and the last question I asked was "are your stoves ULC certified. I expected a 'yes' answer automatically but the answer was 'no'. Installing one to US installation specs in Canada is illegal according to the info I got from WETT head office and the local building inspector. I spent many hours researching and protesting that one, just like I am on the EPA stats. Yup, I'm a PITA sometimes.

 

[BrotherBart]

Are you sure it isn't ULC, not CSA, that is the cert problem in Canada?

 

[DougA]

Are you sure it isn't ULC, not CSA, that is the cert problem in Canada?

My bad. Brain freeze due to weather and cabin fever. You are correct. I edited my post.

 

[tarzan]

Why would theEPA even bother to publish those default numbers with presumably some actual numbers amungst them? At the very least they should make it clear to the average consumer what they are looking at or post a link to Brother Bart so he can splain it to us.

 

[TheRambler]

I don't know exactly how accurate the btu numbers are, but i think they are generally(broadly speaking) correct. I had a H300 before i replaced it with a PH. Now, i am not looking up the exact numbers at the moment, but these are close enough to make my point. EPA testing showed the H300 to be like 30,000btu/hr at default efficency. Hampton claimed the H300 was around 50,000 btu/hr and like 81% efficient. Compared to the PH which is claimed and tested at 73k btu/hr and like 83?% efficent i believe. The H300 put out nowhere near 50k btu, i dont know if the 30k is accurate but its definitely more in line than 50k. Running the PH on high i firmly believe puts out around 70ishk btu because it heats my house in a hurry on the same load size of wood that i was using in the H300 which lends me to believe the efficiency rating is accurate as well.

It is important to remember that the high btu numbers seen on the epa chart are for peak output. A given stove may put out more heat overall through its burn cycle, but that random stove with a smaller firebox with a really high btu number might just peak higher and then have a sharp drop off. The EPA isnt measureing overall btu output just peak btu and lowest btu.

 

[pdxdave]

Did the EPA list the Lopi at 73,000 or did Lopi? I didn't think any tested stove had tested that high before the PH?

I suppose it was Lopi - didn't look too closely into it at the time.

 

[tarzan]

It is important to remember that the high btu numbers seen on the epa chart are for peak output. A given stove may put out more heat overall through its burn cycle, but that random stove with a smaller firebox with a really high btu number might just peak higher and then have a sharp drop off. The EPA isnt measureing overall btu output just peak btu and lowest btu.

But how could a small stove put out more heat than a larger stove, overfiring?

Incase anyone hasn't realized yet I'm not a "stove guy" just a dumb#$$ with a stove! But I can't figure out how a small steel box load of wood can put out more heat than a big steel box load of wood.

IMO BTU numbers are for the most part useless or as Rideau said you have to be knowledgable, which I'm apparently not cause I can't make sense of them. I think I will stick with sizing my stove by the size of the stove.

 

[TheRambler]

A smaller stove isnt technically putting out more heat, it just has a higher peak. The fact that one stove is smaller or bigger than another is really irrelevant in this regard for this case. Stove A might peak at X but only maintain X for 10 minutes, where as stove B might peak at Y and hold that peak for 2 hours. The chart isnt saying that one stove heats more than another stove neccesarily, though it can mean that but its case by case dependant.

Every stove is designed a little different and as such each stove will put out different btus. Stove design plays a critical role here, as one stove might put alot more heat up the flue, where a different design might keep more heat in the firebox/stove. Such is the case with the Progress Hybrid for example. Due to the heat exchangers and higher stove mass as a whole, the stove is capable of putting out a very high peak btu when compared to other similarly sized stoves of a different design.

I think the bottom line is all of these stoves are tested in the same manner. Yes, the amount of fuel used is based on firebox size, but other than that its pretty much the same across the board. The BTU numbers published on the epa chart arn't made up. They are actual test results from certified labs. They are only a small part of the big picture. But if your in the market for a stove the numbers can be useful when you are comparing 2 stoves of a similar firebox size. I wouldn't even begin to rely on the numbers when comparing say a 1.5cuft box stove to a 3cuft box stove. But when your comparing like products, i thinl the numbers are very helpful.

 

[rdust]

I wouldn't call the numbers BS just worthless in most of our "real" world environments. How long does anyone run their stoves for max BTU's? How long can most of our stoves run at their max before turning into a puddle on the floor?

This thread happens every year and the people with the stoves that tested high say "yeah theses numbers are perfect" the rest of us with stoves other than the best tested stoves have to wonder how we're heating our houses with all these other stoves. Honestly I wonder how I can heat this place with a BK stove since the stove is only good in milder climates like the Pacific N/W or some other place that doesn't get cold like Virginia.(sorry Bart I had too!)

 

[Oldman47]

Your mileage may...scratch that....WILL vary UNLESS you perfectly match those conditions.

Does that mean ratings are meaningless? No. Ratings based on a consistent test provide a consistent data point to compare. This applies to both cars and to stoves and to most other items.

A car rated for 35 mpg will get better mileage in the same conditions than one rated for 25 mpg. A stove has less rigorously controlled variables, but one rated for 50,000 BTU/hour can be reasonably expected to have a higher peak output than one rated for 30,000 BTU/hour.

I would love to agree with you but that is wrong. I had a car rated at around 35 MPG that actually gave me a fairly consistent 45 MPG, it was a little car. I now drive a car rated at 38 MPG and am lucky to ever reach that number. Both were 5 speeds and the same manufacturer. I drive my present car about the same as that earlier one. Same driver, same driving habits, same everything except the car. The cars are not at all like the ratings would suggest. The one with a better mileage rating is doing worse than the other. I owned both cars for over 5 years so it was not a case of first year or anything like that.

 

[Quentin2]

Cut him some slack rdust it is "NORTHERN" Virginia

 

[Oldman47]

Cut him some slack rdust it is "NORTHERN" Virginia

?
What am I missing?

 

[rideau]

Rdust is making the point that a BK will heat a home in a very cold climate just fine.

 

[Quentin2]

Sorry old man 47 I shoulda quoted rdust, just goofen!

Bkvp has posted some good insight to the inner workings of testing and ratings and how exactly it's done. With some effort might be able to find it.

 

[bobdog2o02]

One more time. The EPA does not require testing for efficiency. They don't care if it heats your house or not. Just that it ain't smoking. They offer manufacturers the option of them publishing "default" values for cat, non-cat and pellet stoves that were developed in 1987 or they can pay ten to twenty grand to have the stoves tested for actual BTU output and efficiency. A very few stove makers have opted to have actual values tested and published.

There are three numbers usually available. The low burn EPA "default" number. The high burn EPA "default" number. The "max" number that manufacturers publish stoking the stove like a freight train slamming wood in it constantly and firing the crap out of it.



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Just curious, do you mind rattling of the top of your head a few of those who have shelled out the Benjamin for the testings.

 

[BrotherBart]

I know that BK and Woodstock did. Haven't pursued who else has. It is noted on the EPA cert list.

 

[begreen]

Newest models seem to be where the testing is happening. FPI (Regency) and Travis have done it for their hybrids.