Firewood - The Truth

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source I've found):
<http://www.fpl.fs.fed.us/documnts/pdf1987/white87a.pdf
In there a range there of 9120 BTU/lb for Redwood to 8440 BTU/lb for Yellow-poplar. Thats an 8% difference. Not huge but significant.
There is another document at:
<http://www.fpl.fs.fed.us/documnts/fplgtr/fplgtr29.pdf
That has a much more comprehensive list. This shows a range of ~7300 to ~12200 BTU/lb. The highest is more than 60% above the lowest. Now there are different studies all in that table, but even comparing like studies gives almost as big of a range of values.
The softwoods are generally higher because of their resin content. (that pitch is just like oil)
Hope that helps.
Dan
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That we knew, Dan. I've mentioned it a few times already, as have others. Plus or minus extractives, is the phrase I've used. The greater the amount of extractives, the greater the energy density, which, as you note, can vary from a resinous high of 12K to a miserable low of 8K 33% (50 if you're trying to make your argument) is a big swing, but the majority clusters within 10%. Your low is for bark.
Then there's the footnote - "clusters at 8500" and the disclaimer of a post hoc study that the methods used to determine the data were not consistent.
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Comparing cellulose to cellulose is pretty dull, but try resinous larch vs birch or willow. Even though the pound per pound difference is much less than the volumetric difference, it's still significant.
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Andy Dingley wrote:

Read a book. Read several. We're talking about per pound not volume. Dried wood of any type is composed mostly of cellulose and lignin. Slight differences in aromatics. You may be thinking about density, that's why we are comparing BTU's on the base of weight.
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vaguely proposed a theory ......and in reply I say!:
remove ns from my header address to reply via email

If you had _posted_ to the thread that would have made it all a lot easier to follow on....
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According to these guys, it is 8600 per pound. http://www.urbanext.uiuc.edu/hortihints/0110b.html
When considering the use of wood for heat, University of Illinois Extension foresters offer the following information and advice: All species of wood has the same Btu (British Thermal Units) per pound of wood; roughly 8600 Btu per pound @ 15% moisture content. As the moisture content goes up in the firewood, the heating value goes down (less Btu's) because more energy (heat) is needed to drive off the moisture in the wood before it will burn. This is why firewood needs to be seasoned at least 6 to 9 months before it is burned. Freshly cut wood is not very efficient for heating use.
These guys are using 20% moisture for 7,000 Btu
http://www.oznet.ksu.edu/library/forst2/c640.pdf
Comparison to Other Fuels
How does wood compare to other fuels? In most
cases wood will be used as supplemental heating to
your conventional system of natural gas, L.P. gas, or
electricity. Table 4 gives Btu values of common fuels.
TABLE 4. BTU VALUES
OF COMMON FUELS
WOOD (per pound, high heat value,
20% moisture) 7,000
NATURAL GAS (per cubic foot) 1,000
L.P. GAS (per gallon) 92,000
ELECTRICITY (per kilowatt hour) 3,412
FUEL OIL (per gallon) 140,000
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Dunno. But I do know this - it takes a bigger piece of pine to make a pound of wood than it does maple, and that pine is going to generate a lot more creosote than that piece of maple unless it's really dry - which makes it even lighter. Net/net - pine (and poplar) suck for firewood in the northeast. I burn some pine but more to get rid of it than for any real heat value.

Isn't that how it's supposed to work?

Dunno. Only know what my experiences are.
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Cut it, split it, stack it, and burn it. Don't analyze it.
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TaskMule wrote:

Unless it's red gum. Cut it, whack on it 50,000 times with all manner of splitterly devices, then saw the damn stuff up with a chainsaw after failing utterly to split any of it. Then burn it.
Or better yet, turn on the gas logs when you're in the mood for a fire. Every time I start to get romantic about how much different it used to be having a real fire in the fireplace, I just look at my old mangled maul standing in the corner and smile. :)
(I was a lot more lithe and lean and stuff in those days though, boy. Especially swinging that damn 16# sledge that used to belong to my great grandfather.)
--
Michael McIntyre ---- Silvan < snipped-for-privacy@users.sourceforge.net>
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Maybe that was part of the problem. My neighbors next farm south had been doing wood forever. One used a maul (go-devil for NE folks), the other an axe, to split elm. Sixty seven and seventy three were their ages, with the 73 swinging the axe....
I retired my sledge this year. No more kids in residence to help the old man with 4' lengths. Susan and I went to 20", and a splitter.
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I used a maul instead of a sledge. The hard part of using a sledge is getting your wife to hold the wedge while you swing.
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wrote in message

With 4' lengths, I did the Abe Lincoln method. For stovewood, two men - one setting, one swinging a maul - can outwork a splitter. As long as they're not old and fat....
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I'm thinking the small particle size leads to more efficient and complete combustion. Similar to the atomization of fuel in an internal combustion engine.
But then again, what the hell do I know?
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Naw.
It's because it explodes in the presence of static 'lectricity and PVC.
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efficiency never before possible. People have gotten less competent to
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wrote:

You didn't ground that sucker like Michael Baglio posted? ;-)
Patriarch, using sawdust for 'slow oxidation' in the carbon cycle...
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On Wed, 09 Feb 2005 23:35:44 -0600, Patriarch wrote:

<http://www.google.ca/groups?hl=en&lr=&ie=UTF-8&selm |9nvvg39cd5aeqva39icg99990l91t11k%404ax.com>
Note the google.CA rather than google.COM domain. I like the old interface better, which is still being used by "nationa" googles. I wonder if you Merkins get redirected to google.com when you type in google.ca.
--
Luigi
Replace "nonet" with "yukonomics" for real email
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I've noticed the redirect doesn't happen if I type a phrase into the search pane in Safari (Mac browser) but does if I type the url directly.
Most odd.
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sometimes orange water gibbon bucket and plastic." -- Mr. Burrows
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On Wed, 09 Feb 2005 23:35:44 -0600, Patriarch wrote:

Note the google.CA rather than google.COM domain. I wonder if you Merkins get redirected to google.com when you type in google.ca.
--
Luigi
Replace "nonet" with "yukonomics" for real email
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Simple, use two different BTU measuring devices. I worked in a lab for many moons. If you're looking for a specific piece of data, we could deliver it.
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And I thought a btu was a btu. hmpft!
--
Regards,
JP
"The measure of a man is what he will do while
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