[Stoves] Controlling wood moisture content for stove testing in a lab

[Crispin Pemberton-Pigott]

Dear James and Jim

At the SEET Lab in Ulanbaatar we are also using freezing for preserve
moisture content of coal and wood. You guys at SeTAR Centre are luck in that
you have a proper wood drying oven so you can do individual tests before and
afterwards really easily. 

We get a batch - about two tons - and keep in in a container outside where
it is typically -20. The fuel is rated in a separate lab (WWB) and we record
it.

Homogenising to a particular level is best done in a conditioning cabinet
which is saturated inside, and kept at a constant temperature. The
combination of a given humidity level (100%) in the air and temperature
gives a nearly constant % WWB level in the fuel.

This does not work so well for coal so the tests are relative to each other
and we use a moisture level that is at least typical. This year we are at
26.1% and will probably not run out before spring. Variations between
sources is more significant that between 20% and 26% moisture because the
chemistry is so different.

I think there is an old message from Tom Miles on this list (see archives)
giving the method for getting wood to a given % moisture content.

Regards
Crispin