[Stoves] Calculating firewood volume to weight, daily firewood use

[AJH]

On Mon, 11 Sep 2006 16:38:31 -0400, Sharon Gordon wrote:

>Some of the statistics I've found are in volume measurements.  If you have normal type dry firewood--generally hardwood, how much does 1m3 (and is that one cubic meter as I assume) of wood weigh?

Difficult question to be precise on because of wide variation between
species.

Wood has a basic density and that is the weight of a bone dry piece of
wood divided by it's volume. Typically oak in UK will be around
550kg/m^3 of solid wood. This actually varies depending which part of
the stem or branch the wood comes from. When it is freshly felled the
wood contains water in the cells and in association with the cell
walls. This water forms nearly 50% of the fresh felled weight of a
piece of wood. So the bone dry cubic metre of wood that weighs 550kg
would have weighed a bit more than 1 tonne wet (and would sink in a
tank of water).

Then you need to know what a stack of wood contains, with straight,
short billets carefully stacked there will be about 30% air space
between the bits of wood, chopped logs jumbled together and the air
space increases to 50%.

So you really need to know the species, form factor and moisture
content. For burning experiments moisture content and weight are good
enough as most woods have about the same calorific value for a given
moisture content.

AJH