[Greenbuilding] Wood heating - my story

[Lance Collins]

I have a very simple heater supplied by a Canadian who moved to 
Queensland and made heaters to a design he called a 'hot drum'.

It's a cut down 200 litre steel drum with a cast iron door and a hot 
plate on top.    It heats (overheats) a room about 50 
sq.metres.  insulated to R1.5  in the walls and ceiling.
(55 gallon, 500 sq. ft. R9).

I burn about 2 cubic feet of wood a day in the winter.  (Very mild by 
this list's standards,  outside temps about 2 to 10 Celcius).

I cut my own wood so never deal with wood merchants.  When I was a 
child my parents bought wood by the cubic yard,  never heard of cords 
until I joined this list.
The drying rule of an inch a year seems about right to me.  I split 
green wood when I cut it as it's sometimes very hard to split when dry.
I've observed that wood that has dried for several years still burns 
well even when dripping wet from a shower of rain.    I wonder 
whether cells of green wood have some insulating property which slows 
the burn rate of the wood compared with the same size of wood dry 
internally but the same amount of water on the surface.

The drum sits on feet with a 200 mm space underneath.  The drum has 
about 50 to 75 mm of ash in the bottom (no grate) and is safe to 
touch underneath when the rest of the drum is very hot.   Our old cat 
used to sleep under the heater.
Wood ash seems to be very good insulation.

My wood is mostly eucalypt with some acacia.   When I've burned 
scraps of radiata pine from woodworking projects the heat output is 
low by comparison.

And I find my ceiling fan is quite effective in keeping the heat 
evenly distributed.

Lance
(100 Km NE of Melbourne, Australia)