BTU's / species

[wg_bent]

The question on BTU/Species seems to pop up now and then, so I though I'd post this.

I didn't realize is how low in the list Elm is. (Did I mention how much I hate Elm?)


Species Btu/Cord
black locust26,500,000
hickory 25,400,000
beech 21,800,000
hard maple 21,800,000
red oak 21,700,000
yellow birch 21,300,000
yellow pine 20,500,000
white ash 20,000,000
white oak 19,200,000
soft maple 19,100,000
black cherry 18,500,000
white birch18,200,000
sweetgum 18,100,000
elm 17,700,000
yellow poplar 15,900,000
hemlock 15,000,000
red spruce15,000,000
fir 13,500,000
white pine13,300,000
basswood12,600,000

 

[Eric Johnson]

Better check the white oak rating again, Warren. It belongs up with the hickory & locust.

 

[wg_bent]

Well, I checked, and the number I copied and pasted is still the same. I didn't do the research...Virginia State University did. I will say that I was surpeised also, o.k. here's another source:
Supports your point.
Fuel Values of Some Common Woods
Wood Type (Assuming 20% Moisture Level) (lbs. per cord) Fuel Value per cord in BTUs (British Thermal Units)
Shagbark Hickory 4400 30.8 million
White Oak 4400 30.8
Madrone - 30.0
Sugar Maple 4100 29.7
American Beech 4000 28.0
White Ash 3700 25.9
American Elm 3400 23.8
Douglas Fir 2900 21.4
Cedar, Incense - 17.5
Ponderosa Pine - 17.0
Eastern White Pine 2200 15.8

 

[Corey]

Well, I second the thought that elm is just miserable wood. Terrible to split, smells bad when wet, not much better dry and doesn't put out much heat. I think the first list has oak/hicory/locust and a few other woods a little low...second list has them a little high. I have usually seen them in the 24-26 Mbtu/cord range. Both lists leave off the greatest wood known to mankind...hedge (aka osage orange). It usually pegs right about 31Mbtu/cord if you can find a list that includes it.

I do pity our northern friends who don't have access to the good hardwoods!

Corey

 

[wg_bent]

The fastest rotting wood I've seen...that is if you can call it wood... is Sumac. That stuff rots within a year if left on the ground. Sometimes almost to the point of becoming dirt. It's very lite when cut green, and if seasoned, I suspect it would burn similar to pine. I tend to avoid it for burning. Seems better suited to making mulch.

 

[bruce56bb]

here is a link to a similar chart with somewhat different btu ratings. in our area after the dust bowl the farmers started planting hedge rows to help combat the wind erosion. the common tree of choice was the osage orange(called hedge here). there are miles and miles of the stuff. it does burn very hot but on the downside it pops a lot and if its been down very long it gets VERY hard.
http://ianrpubs.unl.edu/forestry/g881.htm

 

[snowfreak]

I live on the East Coast and grew up in the Midwest but have never heard of or burnt Madrone wood. Is this something on the West Coast? The first time I saw a BTU chart with Elm listed I could not believe it. They should figure out how many BTU's your body puts out when spliting elm. It would probably top the chart with that combination. Although I've found that if the elm tree is standing dead and the bark is falling off or entirely off it splits much easier than when green.

 

[begreen]

Yes, it's a northwest wood, I was surprised to see it mentioned. We have several of them growing on our property. It's a pretty tree, has broad shiny year round leaves and a distinctive red bark. Madrone is my favorite wood for burning.

 

[snowfreak]

Thanks for the photo, it looks like a nice tree. From your picture it looks pretty knarly (hard to split) I wonder if the wood can be used in furniture or for hardwood boards.

 

[DavidV]

didn't know hickory rots fast. I better get that hickory tree up off the ground before it's wasted.

 

[Sundeep Arole]

I imported the table bruce56bb linked into excel, and computed the heat value per pound (not heat value per cord). Result - no matter which wood, if you are burning dry wood then you get about 695 BTU/lb regardless of which wood it is. If you burning green wood, the heat values range from 50 to 90 percent of the dry wood, depending on the species. However, some woods, like osage-orange, white ash, juniper, douglas fir, locust, ironwood and red cedar give you about 90 percent of the heat value of dry wood even when burned green. If you are forced to burn green, looks like these are the best choices.

 

[begreen]

Thanks for the photo, it looks like a nice tree. From your picture it looks pretty knarly (hard to split) I wonder if the wood can be used in furniture or for hardwood boards.

Madrone is easy to split while green and much harder when seasoned. It is a slow seasoning wood, normally we wait 2 yrs. before burning. Yes, it is used for furniture, flooring, etc. and has beautiful grain patterns. The burls make some grand pieces. It's also a practical tree, almost every part of it is useful. The fruit is a small red berry that tasts a bit like a strawberry. They are exceptionally beautiful trees and I feel a little badly when I have to take one down. Walking through a grove of madronas is like being surrounded by ballet dancers.

for some examples go to: http://www.nwfinewoodworking.com/judith_ames/diningroom_furniture_03.htm or http://www.nwfinewoodworking.com/turnings/wood_turning_6.htm This is a site to get lost in if you love woodworking.

 

[Corey]

I imported the table bruce56bb linked into excel, and computed the heat value per pound (not heat value per cord). Result - no matter which wood, if you are burning dry wood then you get about 695 BTU/lb regardless of which wood it is. ...

Are you sure that is not 6950 btu/lb? That would be in the ballpark I normally see quoted...7000 - 8000. I think many of those tables are computed by using lbs/cord times a standard btu figure. I have seen it said many times "all woods have approximately the same btu/lb, but density does vary" That seems a little strange because you would think that resinous wood such as pine may have slightly more btu? But I guess it is close enough not to matter in the long run.

Corey

 

[Sundeep Arole]

Cozy you are right - it is 6950 btu/lb, not 695 btu/lb, I mis-posted.

It did seem a bit of a coincidence that all the numbers were so close, but you are probably right, likely all I have done is de-constructed the way the table was made. I did find however that the btu/cord for green wood was not constant, but perhaps even that figure has been arrived it not by experimental measurement but rather by measuring relative densities of dry wood vs. wet wood for a given species.

I presume then in that case it must mean woods like osage, white ash, juniper, douglas fr, etc. simply don't hold much moisture to begin with?