firewood red oak vs white oak

[TXCraig1]

Craig,
Whats the Btu on the Maple vs the red Oak ?
thanks!

They are about the same ~23-24MBTU/cord or 6.2-6.4KBTU/lb

The oak is probably a little higher, but the difference is likely not significant.

[Polo]

Craig,
Whats the Btu on the Maple vs the red Oak ?
thanks!

It does kind of depend on the species of maple. Here's a chart I use for comparisons.

http://www.chimneysweeponline.com/howood.htm

[pizzaneer]

Not sure I agree with the chart, but maybe I'm reading it wrong.

  In my experience, Beech and Maple are nowhere near Oak for length of burn.  Beech burns intensely but briefly without leaving much of a coal, Maple is somewhere in the middle, and Oak lasts a long time and crumbles into coal that lasts a long time too.

I use beech to start the fire, then oak splits and whole 6-8" diameter branch pcs to maintain it.

[TXCraig1]

Not sure I agree with the chart, but maybe I'm reading it wrong.

  In my experience, Beech and Maple are nowhere near Oak for length of burn.  Beech burns intensely but briefly without leaving much of a coal, Maple is somewhere in the middle, and Oak lasts a long time and crumbles into coal that lasts a long time too.

Remember, a BTU is a measure of energy - not power (the rate at which energy is used). A lot of heat for a short amount of time could be the same amount of energy as a smaller amount of heat for a longer amount of time. That being said, some of the numbers on the chart look too low to me.

[Polo]

Not sure I agree with the chart, but maybe I'm reading it wrong.

  In my experience, Beech and Maple are nowhere near Oak for length of burn.  Beech burns intensely but briefly without leaving much of a coal, Maple is somewhere in the middle, and Oak lasts a long time and crumbles into coal that lasts a long time too.

I use beech to start the fire, then oak splits and whole 6-8" diameter branch pcs to maintain it.

There are different BTU charts and they will give you different values. If you scroll down the page there is a link that explains how they came up with their numbers. Like I said, I only use these charts as comparisons between wood species. I wouldn't stake my life on the numbers.

There are also other charts that discuss the burning characteristics of different species as well.

[3.1416]

All cellulose (wood) contains the same BTU's. It's just that some woods are denser and pack more cellulose into a tighter space. So, we say white oak has more BTU's than red oak. But that implies that we are talking about per cubic foot or cord or some given volume.

Green wood uses up a lot of its BTU's in drying the wood before it can burn.

An easy chart to find would be specific gravity of various woods. This will tell you instantly which has the most BTU/cubic ft. The higher the specific gravity the more BTU/volume.

If covered, wood will air dry at a rate of about 1" per year on each surface. It will eventually dry down to around 12 to 14 percent moisture. It won't go any lower than that in outside ambient conditions. At least that is true for where I live. Dryer climes may go lower. So split your wood quickly. Also cut it in the winter while the sap is down to gain a little advantage. Plus it warms you twice. When you split it and when you burn it.

By the way I believe that red oak has a S.G. of around 0.96 and white oak is up around 1.04. One floats and one doesn't. For 2 cubic feet the weight difference would be around 10 lbs. Which gives you an idea that you would need to burn 10 lbs more r.o. to get the same BTU from 2 cuFt. of w.o. These figures are from memory from 10 years ago when I ran a hardwood sawmill. Take into consideration that I have CRS. (Can't Remember Sh..) Hope this helps those who weren't raised with a woodstove for heat.

Oh, one more trick. Frozen wood splits a lot easier than warm wood. Red Oak easiest of all.

[TXCraig1]

All cellulose (wood) contains the same BTU's. It's just that some woods are denser and pack more cellulose into a tighter space. So, we say white oak has more BTU's than red oak. But that implies that we are talking about per cubic foot or cord or some given volume.

Green wood uses up a lot of its BTU's in drying the wood before it can burn.

I don't remember anyone discussing BTU's - rather BTU/cord or BTU/lb - nothing was implied.

FWIW, all cellulose may have the same BTU, but wood is not all cellulose. The cellulose/lignin content is not the same for all woods (lignin is 15-20% for typical hardwoods), and lignin is a higher energy fuel than cellulose. This is probably not particularly important in the larger picture.

Green wood doesn't use up any of its own energy in drying. The total available energy in the wood doesn't materially change as it drys. Dry wood burns better because it doesn't require heat, that would otherwise go to pyrolysis, to drive off the moisture. It also burns more efficiently due largely to the higher temperatures possible without the water and water vapor present. 

In most cases, there probably isn't enough difference in BTU/lb to overcome the cost difference. The bottom line when picking [hard]wood for the WFO is #1 - dry, #2 - cost. For all practical purposes, the BTU discussion is meaningless.

[vincentoc13]

Theres a guy in my area selling avocado wood, just wondering if anyone has tried it?

[Woodfiredovenpizzero]

Vincent:

I have found avocado to be too soft and retains a lot of humidity, therefore not much heat output.

Edgar