Earl Wrote:
-------------------------------------------------------
> I'll beat Dan to the punch here. The best wood is
> split, dry pine with lots of pitch in it. It
> burns hot, but rather quickly. Oak is like hard
> coal. It burns slow and makes low heat. Pine is
> "uphill wood", oak is "downhill wood".
>
> If is isn't seasoned and dry, you might as well
> pack up and go home. We found out that when
> Eureka ran in Chama in 1997. I had arranged for
> wood the previous fall. The cutter said he had
> just cut several several pines and by the spring
> they should be good and dry.
>
> He lied... If he had blocked and split them in
> the fall, all would have been good. But he didn't
> do that until spring when I reminded him about the
> wood order. The result was many cords of wet
> wood, that would not burn until it sat in the
> "drying kiln" (aka the "Eureka's Firebox) for
> about 20 minutes. We had lots of troubles.
> Eventually Marvin came to the rescue and trade
> about 10 cords of dry pine he had for 15 cords of
> green wood we had.
Pay close attention to Earl here!
I work in the wood combustion industry and have spent time in the labs burning it with the experts. While it is true that the energy (BTU's) per pound is pretty much the same across the species lines, that is often the least important factor, even beyond the fact of how much energy per volume you can store in the tender (try cottonwood, for instance). As Earl points out, the combustion rate is often more important, and that is
not the same for the different species.
As Earl also points out, seasoning is a tremendous factor. The water remaining in wood must be evaporated in the combustion so the 8500 BTU's per pound theoretically available gets down to 6900 or so with wood seasoned to 20% moisture content (wet basis), the accepted standard for "seasoned" wood. Serious planning and execution is required to get it there and to maintain it there before burning. I have measured the moisture content of hundreds of sources of firewood of many different species and have yet to measure commercially sourced firewood below 30% moisture content as furnished.
So it comes down to which species burns best when not completely seasoned (green). Old timers of my acquaintance heating with wood stoves in Northern California and Southern Oregon preferred Madrone for that reason over oak, both of which were readily available as well as Douglas fir and pine; the Madrone burns better green than the oak, with a with a higher heat output per volume than the fir, and held a fire longer than the pine. But they had pine/cedar/fir for kindling.
And of course that can create other issues; one old logger and miner I knew had a coffee can under the stove elbow to catch the creosote constantly running down the chimney. Could hit it from across the room spitting his chewing tobacco, too.
I can see the wise engine crew knows how to use fuel characteristics to their advantage!
Timothy
Edited 1 time(s). Last edit at 07/26/2021 07:01PM by heatermason.
