EPA Ratings on my stove are different then manufacturers numbers?

[Bhowe007]

I just picked up my new insert this morning and I'm getting very excited about putting this thing in. I bought an Enviro Venice and I think I got a pretty good deal. About $2250 for the stove, the surround, optional base plate and tax.

Anyway, do the ratings that the manufacturer uses on their website and general literature differ from the ratings that you see on your actual stove? The ratings on the website and all the literature that I have for the stove say it is 75% efficient and about 75,000 btu's of heat output. When I looked at the tag that comes with the stove it says the stove is in the range of 60-63% efficient (there is an arrow that points to a range of values) and the btu output is 9,900 to 34,000 btu's. Maybe it's under different operating conditions?

Brad

 

[Nasty Ash Beech]

I noticed differing efficiency ratings when I bought my Enviro Kodiak 1700 insert last fall. All I can tell you is that those stoves are very efficient and I am very pleased with mine. They put out alot of heat for sure and run very clean.

 

[Bhowe007]

Good deal, I love hearing that.

Did you use the surround on yours? I've read a lot of threads that say they get a lot more heat with the surround off the insert.

 

[Nasty Ash Beech]

I do have the surround on mine and like the way it looks. My fireplace opening was just big enough to fit the stove so I'm not sure if I would gain any more heat by not using it. I think the way these newer inserts are made they are designed to not lose much heat out the back anyway. You will want to use your fan, the heat pours out when it is on. I'll attach a pic of mine...

 

[Bhowe007]

Very nice, I can't wait to put mine in. Thanks Beech.

 

[BrotherBart]

The EPA efficiency numbers are a "boilerplate", that being one number for cat stoves and one number for non-cats. EPA testing doesn't test the efficiency of each stove just the particulate emissions. The stove manufacturers have just been using those numbers instead of submitting their stoves to the expensive efficiency testing process. But they also publish their own "in-house" cord wood testing numbers which are higher. And also unrealistic because you would have to stand in front of the stove and chain feed it like a locomotive boiler to run it that hot all the time.

All that said, when the energy efficiency legislation came along the industry trade association talked Congress into accepting "lower heating values" like those used in Europe for the efficiency number so that wood stoves could be eligible for the 2009-2010 tax credit. Those numbers ignore the energy used to boil latent moisture out of the wood so those numbers are higher too. Somebody came up with a way to derive those values from the stack gas measurements in the EPA testing results and so overnight all EPA compliant stoves met the requirement and were eligible for the tax credit.

All of which has not one damned thing to do with how your stove, with your wood and how you load and burn it will heat your house. Bigger stoves make more heat, smaller ones make less heat.

 

[Highbeam]

For reference, the figures from Hearthstone were also much different than the EPA tag when I bought my stove.