How many BTU's do I use?
- Thread starter kenny chaos
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SteveT
Feeling the Heat
If you know the efficiency of your appliance either way will get you to the same answer.
Say you are working with heating oil and you know your furnace operates at 80% efficiency. You get 139,000 BTU for every gallon purchased; you get 80% of that into the house (about 111,000 BTU). Same method will work for any appliance.
EDIT: Just looked back and saw you wanted it specifically for cordwood. Oak is about 24 million BTU/cord.... do the same correction based on your stove efficiency.
Say you are working with heating oil and you know your furnace operates at 80% efficiency. You get 139,000 BTU for every gallon purchased; you get 80% of that into the house (about 111,000 BTU). Same method will work for any appliance.
EDIT: Just looked back and saw you wanted it specifically for cordwood. Oak is about 24 million BTU/cord.... do the same correction based on your stove efficiency.
In reference to this chart- https://www.hearth.com/econtent/index.php/articles/heating_value_wood
I want to figure how many BTU's I'm getting out of my stove.
What's the difference between BTU's/cord and recoverable BTU's?
Thanks-
Ken
I want to figure how many BTU's I'm getting out of my stove.
What's the difference between BTU's/cord and recoverable BTU's?
Thanks-
Ken
SteveT
Feeling the Heat
kenny chaos said:
In that the chart the BTU/cord is what is in the wood and the "recoverable" is always 70% of that. So the chart is made up for a "typical" stove efficiency of 70%.
Using red oak as an example....
If you feed one cord into the stove that's 24 million BTU. You get 70% of that (16.8 million BTU) into the house (or "recovered").
^^ +1
Though IMHO, I think 70% might be a bit high. I know many stoves are rated around 70%, but I believe that is under highly controlled and optimal conditions of everything from wood size, stacking, moisture content, air flow, draft, etc. For real-world burning where we aren't constantly tweaking everything on the stove and burning the perfect sized and dried wood, 60% might be a little closer to reality, or maybe even 50% if you want to err on the side of caution.
Though IMHO, I think 70% might be a bit high. I know many stoves are rated around 70%, but I believe that is under highly controlled and optimal conditions of everything from wood size, stacking, moisture content, air flow, draft, etc. For real-world burning where we aren't constantly tweaking everything on the stove and burning the perfect sized and dried wood, 60% might be a little closer to reality, or maybe even 50% if you want to err on the side of caution.
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