Heating with Wood
I currently use a propane fireplace. Its convenient....and that is where it ends. Propane as an energy source is non-renewable, it's shipped in from outside of province and there have been times when the island supply has been depleted...not wood though...it's everywhere. Sure would have been convenient to have had a wood stove during all of those rolling blackouts a few years ago. Wood can be good! Besides being a heat source, the hours of mesmerizing, hypnotic flames are enjoyable to watch.
Now lets talk energy. A 2000 sq. ft. Passive House modelled with the climate data for St. John's would require a total yearly demand of 25.3kWh/sq. m. So the total heat demand for the house would be about 5000 kWh. This is an amazingly small number. A cord of dry birch contains about 21.6 million BTU or 22.9 GJ (Giga Joules) which is equivalent to about 6400kWh of recoverable energy. Many EPA stoves have an efficiency of about 80%. So 1 cord of birch would have a combustion heat value of 80% x 6400 kWh = 5120 kWh which is almost equal to the 5000 kWh yearly demand. One cord of wood is a pretty small amount. In these homes, about 1/3 of the heat requirement is taken care of by solar gains. In which case, I am expecting that the house could be heated with about 2/3 of a cord of wood. If you include internal gains then that may make up to another 1/3 so you would only require 1/3 of a cord of wood to heat a house for a year!!!! Now thats impressive!!!
The biggest issue with wood stove is finding one small enough to meet the peak load criteria of 13.3 W/sq. m. At 13.3 W/sq. m., the total wattage required for this home will be about