Wood Burning Tips: Part-2

Wood Wants to be Wet

Really, really wet.  In fact it’s the only typical raw material that holds more water than good soil (usually 120 percent to 200 percent of its dry weight).  The cells in a tree’s wood have such a stubborn grasp on water (it’s their life currency) that they only release it fast enough to avoid rotting under specific conditions.  And it’s in these conditions that you want your fuel-wood.

To make things even more difficult, these conditions are hard to come by in a wet NY winter: Throw a hundred pieces of wood from a plane flying over the Mid-Hudson valley last year and 99 of them (or probably all 100) started rotting within a handful of months.  This is why finding a large supply of dead wood to burn in the forest is often impossible – the fungi get to it first. Burning green wood (more than about 20 percent moisture content depending on species) is a bad idea because it promotes creosote build-up in the chimney which can cause chimney fires, is hard to keep ignited (while at the same time keeping air flow through the stove to a minimum), reduces heat output by 20 percent to 70 percent (causing one to need about one-and-a-half to three times as much wood for the same amount of heat), emits much more air pollution, and is heavier to process.  The only tree in the North East that is burnable in close to its green state is American Ash, due to its exceptionally low standing moisture content, but not commonly found in these parts.

Drying time frame

wet_wood _pile

Under average conditions it takes about one year or more to dry 16-inch cordwood thoroughly.  Under good conditions cordwood will dry within five to seven warm-season months. Under the best of conditions (very sunny, lots of air flow, tall thin stacks, and stacked with lots of air space between the billets) one could dry wood adequately for efficient burning in three to four warm-season months if the billets (pieces of cordwood) are in very short lengths (14 inches or less) and split on most or all sides.  Even small billets that are unsplit take a very long time to dry as the bark holds moisture in the wood very effectively.

Remember that wood only really dries in New York State between April and November when temperatures are above 40°F and humidity levels are relatively low.  A well-sited and -built wood stack does most of its work during July through September with high heat and low humidity. A good wood shed works all year long. Our next blog will be about storing wood and about the best wood shed we ever built.

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