Stove efficiency calculation

Do you know many peoples looking to buy a wood stove that read all the lab tests for different stoves then compare the lab results from all the series of different tests before buying a stove ?? If they were doing so , they all would come on the forum to ask : what is the best stove to heat my house LOL.
And most people don't care in the least about a few percentage points one way or another. They simply want a stove that fits their budget and will work for them.

Is it that they can't explain it? Or that you don't understand the explanation? Because it has been explained here quite a few times and you still aren't understanding.
That is your own opinion, and as I can read your not open mind comments, you never understoud the reason of my question.

@bholler @stoveliker @nortcan

I always think of a full pot, to boil that water, direct flame works, but if someone invents some kind of baffle, that water won't boil, only with the heat produced by the flame, this is why I wonder if baffle is really the optimal solution, I agree that heat goes a long way but the power of the flame that licks the metal directly is lost
Ok take the baffle out of any stove and measure the average stove top temps over the duration of the burn. Then compare it to the average with the baffle in place. It will be much higher with the baffle plain and simple. Yes without tge baffle you will probably get a higher peak but it will be short lived

Prometeo
That is your own opinion, and as I can read your not open mind comments, you never understoud the reason of my question.
No apparently we don't understand the reason for your question. Because it has been answered and that doesn't seem to be enough.

No apparently we don't understand the reason for your question. Because it has been answered and that doesn't seem to be enough.
I just talked about YOU. Looks like you dont like or understand my Québec location ? Or maybe you're too busy with your algebra and trigo...LOL

I just talked about YOU. Looks like you dont like or understand my Québec location ? Or maybe you're too busy with your algebra and trigo...LOL
What does your location have to do with the meaning or testing procedure for stove efficiencies? I certainly don't dislike your location I have no reason to. It is irrelevant to our discussion.

kcmclellan
I agree that variation operation (i.e. differences from the testing procedures) will make a large difference in the numbers. Wood loading packing, moisture content, time of charring phase, flue height, outside weather conditions including air pressure, home tightness, etc. etc.

I agree thus that testing is not giving numbers that are what you would get if you measured heat flows at home.

They are meant for govt imposed standards (epa, hence independent testing!), and many mfgs do pick the best numbers to advertise. (As in all ads...)

The point is that you can compare stoves based on these test results as the only difference is the stove, not all the other conditions (see above) as they've been made to comply with specific parameters.

So the number from a report won't mean all for your situation. But the number for one stove is at least somewhat apples to apples compared to another stove ..

I agree that variation operation (i.e. differences from the testing procedures) will make a large difference in the numbers. Wood loading packing, moisture content, time of charring phase, flue height, outside weather conditions including air pressure, home tightness, etc. etc.

I agree thus that testing is not giving numbers that are what you would get if you measured heat flows at home.

They are meant for govt imposed standards (epa, hence independent testing!), and many mfgs do pick the best numbers to advertise. (As in all ads...)

The point is that you can compare stoves based on these test results as the only difference is the stove, not all the other conditions (see above) as they've been made to comply with specific parameters.

So the number from a report won't mean all for your situation. But the number for one stove is at least somewhat apples to apples compared to another stove ..
Exactly very well said.

I agree that variation operation (i.e. differences from the testing procedures) will make a large difference in the numbers. Wood loading packing, moisture content, time of charring phase, flue height, outside weather conditions including air pressure, home tightness, etc. etc.

I agree thus that testing is not giving numbers that are what you would get if you measured heat flows at home.

They are meant for govt imposed standards (epa, hence independent testing!), and many mfgs do pick the best numbers to advertise. (As in all ads...)

The point is that you can compare stoves based on these test results as the only difference is the stove, not all the other conditions (see above) as they've been made to comply with specific parameters.

So the number from a report won't mean all for your situation. But the number for one stove is at least somewhat apples to apples compared to another stove ..
You're right. I think that it would be nice for custommers to also get the overall efficiency (epa) tests results on the stove advertisements with the combustion efficiency tests already advertised, that way it would gives a good idea in % of the heat that is transfered to the space to be heated. Both tests results could be advertised and at the same time be easier to understand .

And most people don't care in the least about a few percentage points one way or another. They simply want a stove that fits their budget and will work for them.
Yep effectiveness and affordability are the only thing I care about. With so many other variables not much matters. A guy heating with a 76% efficient stove and loading it with seasoned hardwood will be much happier than a guy with a 82% efficient stove and feeding it cedar. Stack, wood, weather, operator, house and on and on. You couldn't duplicate the factory testing if you tried.

It's surprising how many times the word efficiency and not efficient are used on the forum and in many other places to describe so many different meanings.

It's surprising how many times the word efficiency and not efficient are used on the forum and in many other places to describe so many different meanings.
Not really different meanings. It's all about getting the most out of what ever you are using

It would be fine if epa ask to manufacturers to indicate on advertisements : the Combustion efficiency with a short description on it and ALSO the overall efficiency with a short description on it. The last one is the percentage of heat that is transfered to the space to be heated when a load (wood., pellets..) is burned. Overall efficiency is a better measure than combustion efficiency of the amount of heat that is delivered to the home.

It would be fine if epa ask to manufacturers to indicate on advertisements : the Combustion efficiency with a short description on it and ALSO the overall efficiency with a short description on it. The last one is the percentage of heat that is transfered to the space to be heated when a load (wood., pellets..) is burned. Overall efficiency is a better measure than combustion efficiency of the amount of heat that is delivered to the home.
Yes of course heat transfer efficiency is the more important factor when it comes to heating the home

i have a mixed batch of wood .spruce,ash,maple ,birch,pine maybe some beech'how is a manufacturer going to be able to promise me anything .every fire is different from time burnt to heat output,give general sqft heating capacity and i'm good .

i have a mixed batch of wood .spruce,ash,maple ,birch,pine maybe some beech'how is a manufacturer going to be able to promise me anything .every fire is different from time burnt to heat output,give general sqft heating capacity and i'm good .

This, way to many variables. Things change depending on wood type, wood moisture content, chimney height, internal/external chimney, insulated/non insulated chimney, outdoor temperature, outdoor wind speed, etc etc etc.

Wow lots of talk about a question that in my mind is less relevant than other factors in our lives. More Efficiency saves wood and that saves time and or money.

Air sealing and insulation have a greater effect on this savings than the efficiency differences between modern stoves. How you operate your stove has effect.

No one drives in the exact manner to which epa calculated mileage for vehicles but we use it as a representative guide. We generally don’t compare a sub compact mileage to that of a truck when we are shopping. But it’s there for us to that if we wanted.

Stove top temp is a meaningless number for any efficiency calculation as I could blow lots of cold air across it lowering the temp. This could possibly Increase the efficiency. Instead we should focus on firebox temps. But those high temps are hard to measure.

bholler