How Much Heat is in One Pound of Wood? by Sam Foote, P.Eng

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Just so you guys know, I'm good with all kinds of heating with wood and wood burners.

I just wanted to post some interesting information.
I agree the numbers are interesting, just wanted to know what usefulness do they provide... Makes me wonder what the btu/lb of coal is.
 
I weigh all my wood I burn and keep a spreadsheet which tracks it. I found that PDF last year when I started doing this and am using the 6,000 BTU/lb number for my calculations.

Below is a screen capture from my spreadsheet from back the beginning of December showing the summary of what I use that number for. I started out using all LP in the beginning of the heating season. I have a 75,000 BTU LP furnace which has a rated efficiency of 92% and a Kuuma wood furnace which has an Intertek tested efficiency of 82%-85% (I'm using 82%).

BTU use.jpg
 
I weigh all my wood I burn and keep a spreadsheet which tracks it. I found that PDF last year when I started doing this and am using the 6,000 BTU/lb number for my calculations.
What are you calculating?

Where is @Whitespider? What's your saying about burning wood? Brining it should be the easy part?

Weighing your wood seems silly IMO... What's the purpose again? Do you weigh it before it goes into the stove? What if the weight changes as it sesons?
 
I weigh all my wood I burn and keep a spreadsheet which tracks it. I found that PDF last year when I started doing this and am using the 6,000 BTU/lb number for my calculations.

Below is a screen capture from my spreadsheet from back the beginning of December showing the summary of what I use that number for. I started out using all LP in the beginning of the heating season. I have a 75,000 BTU LP furnace which has a rated efficiency of 92% and a Kuuma wood furnace which has an Intertek tested efficiency of 82%-85% (I'm using 82%).

View attachment 476399
Thanks for sharing. Unfortunately it wouldn't work well if you were burning mixed firewood. Care to share that spreadsheet?
 
Thanks for sharing. Unfortunately it wouldn't work well if you were burning mixed firewood. Care to share that spreadsheet?

I can, but will have to wait till I'm at home.

I weight it before it goes in. I am aware the weight will depend on how seasoned the wood is and it's not exact. I just do it because I like to play with numbers and have something to compare between heating seasons.

Shouldn't matter if it's mixed or not, all wood has roughly the same BTU's per pound. 60lbs of wood, regardless of type, will have ~360,000 BTU's in it. Granted 60 lbs of pine will use up much more volume than 60lbs of white oak, but both will contain roughly the same BTU's. If I fill my firebox with half pine and half white oak, it will weigh less than the same firebox filled with all white oak. Therefore less BTU's.

Actually, weighing wood is more common with those who have gassers with storage. It gives them an idea of how much wood to use in order to charge their storage when they know their heat load.

Using -THIS- site, and comparing all the species of wood it looks like it comes out to ~6,200 BTU's per pound regardless of what species you use.
 
I agree the numbers are interesting, just wanted to know what usefulness do they provide... Makes me wonder what the btu/lb of coal is.
Got this off one of the firewood fuels sheets
1 Wood available heat at 20% moisture 7,000 Btu/pound (128 cubic feet with 80 cubic feet wood volume).
2 No.2 fuel oil available heat 140,000 Btu/gallon.
3 Anthracite coal available heat 12,000 Btu/pound.
4 Natural gas available heat 1,000 Btu/cubic foot.
5 LP gas available heat 91,000 Btu/gallon.
6 Electricity available heat 3,400 Btu/kilowatt hour.
 
Interesting read but the guy tossed out the 44% of wood's weight that is oxygen as if it just didn't matter. He also kept talking about excess oxygen but even with no excess of oxygen you are heating the other 80% of the air you feed to your stove, the nitrogen part.
As a side note, when using an industrial furnace and minimizing excess air while still getting complete combustion of oil or natural gas the typical value for excess O2 is closer to 5% and it is monitored as one of the parameters that is controlled closely. Too little you get smoke, too much and you waste fan power and lose heat up the stack.
 
Interesting read but the guy tossed out the 44% of wood's weight that is oxygen as if it just didn't matter. He also kept talking about excess oxygen but even with no excess of oxygen you are heating the other 80% of the air you feed to your stove, the nitrogen part.
As a side note, when using an industrial furnace and minimizing excess air while still getting complete combustion of oil or natural gas the typical value for excess O2 is closer to 5% and it is monitored as one of the parameters that is controlled closely. Too little you get smoke, too much and you waste fan power and lose heat up the stack.

Actually the typical excess O2 (Not excess air) for solid fuels is 5-7% and for oil or gas about 3%. There are exceptions of course but for newer industrial boilers this is typical.

Reread the article he talks about excess air, not excess oxygen.
 
The old saying goes "pound for pound, all DRY wood heats the same".

That is just what JRHAWK is saying.

It might take a whole wheel barrow full of poplar to weigh as much a half a wheel barrow of oak but they will both heat your house for a day.
 
I think it is something to care about as there is a lot of myth surrounding what makes a quality fire wood.

Our wood burning appliances being limited by volume is not such a big deal when you consider that for the most part they have doors. :laugh:

IMO, no one cares about btu/lb. Amount of fuel going into the stove is limited by volume not weight...

Answer these questions for me...
1. What is the maximum lbs of firewood you can load into your firebox?

2. What's the maximum volume of firewood you can load into your firebox?

[/QUOTE]
Reading between the lines:
Obviously you are saying we care in volumes?
Wait! Now I'm confused again:hi:
 
It's all about climate change, wood with the most btu's grows in the warmest climates.
Also, on the average, a cord of split wood contains 333 pieces.
Is that right eh John? I don't doubt you a bit rainman. Somebodys got to much time:innocent: I think you have just made a Hugh breakthrough on a new marketing tactic John.

Pretty customer: "How much will you charge me for a 'length of your wood' Sir"
* smiles, bats eyes*

John: " Its just 89 cents a length"

Pretty customer: "how many lengths of your wood will I need so I feel warm inside? *sucks on her fingers*

John: " let's make sure you are clear about BUI's first.

Sexy Blonde retorts:
YYYYEEEESSS my X Husdand was a BIG URBAN IDIOT.. or what you said, BUI's...he he

Westboastfaller: God bless her
 
I just glanced at the article presented. Since it started with a premise of moisture content of 0%, the whole discussion is pretty meaningless. Marshy is correct in stoves being limited by volume, but denser woods yield higher BTU per given volume and they weigh more per volume constant.
 

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