madison said:
The first pdf is the best for the science buffs (Battenkiller - you’ll be digging the first link) . Jump to pg 72 for the conclusions.
Very cool, Madison. Can't wait to sink my teeth into this one. But first, on to the sad news...
moisture content limits (acceptable range for resistance meters) 8-24%
That means that by the time you can even begin to trust your meter, the wood is already good to burn. And that's with a pro meter, with species and temperature correction algorithms on board (or using the cumbersome tables instead)...
if you are even half sure of the species you have (at least 1/2 of those new burners posting here seem clueless about the exact species of much of their wood).
At best, a conventional resistance MC meter can be used as a "go/no-go" device when it comes to firewood. The higher the MC reading, the less you should trust it. If you really want to know how much water is left in your firewood, you must do what the scientists do and use the oven-dry method of MC determination. But even that won't help you to see if there is a moisture gradient in the wood (drier on the outside than on the inside) unless you take numerous samples across the thickness of the split. Is
anyone (even me) really up for that?
With the obsessiveness of some folks who insist their wood has to be be below 20% water dry-basis (17% water by weight) through and through in order to burn... good luck with that one. If you buy into that fallacy, you have absolutely no choice but to leave your wood in a windy and covered shelter, well-spaced between rows for several years.
Thankfully, this isn't so, or we'd all have to be holding 15-25 cord under shelter for many, many years. The real truth is that once you've driven out the free water, the wood should burn acceptable well. In most locales, it will continue to dry beyond that point until it averages about 15% water by weight, at which point it will hold all of its magic basically forever, as long as it is kept dry. Allowing it to get wet over and over during numerous summers will only allow it to become deteriorated in time, losing any possible potential heat gain gotten by getting it there in the first place. In very dry parts of the country (much of the West), it will eventually become too dry, although you probably have at least three years before than happens.
I have too much time on my hands during slow months, so I enjoy calling up major stove manufactures and bugging them with silly questions. During one such conversation (I was asked not to quote the maker, so I won't, but it was a real biggie) the engineer I spoke with said this:
"All we really want is to get people to realize that the easiest thing to do is to get their wood cut, split, and seasoned under cover for one full year before they intend to use it. As long as they do that, they can just forget about the moisture content of the wood. If we could get them to burn wood at 30% MC or below, we'd get half the calls we do. The fact is, the vast majority of people using our stoves are buying their wood and trying to burn it right away, and that won't work in any stove. Get it down to 30% and it should work OK."
Humorously, even the engineer seemed confused about the wet-basis/dry-basis distinction, but I'm fairly certain he meant 30% dry-basis (as read on a MC meter, which is 23% water by weight). Interestingly, the fiber saturation point (FSP) of almost all domestic wood, the point where no free water is left and only bound water (in the cells) remains is between 28% and 30% water dry-basis (22%-23% water by weight). H-mmmm.....
Peace out.