Heat Requirements of an “Average” Home

More heat is needed in the following circumstances:
• The heater will handle the January peak loads without backup heat.
• The insulation is inferior (check existing building codes in your area).
• There are very tall or cathedral ceilings.
• High altitude and/or strong wind exposure.
• The heater is not freestanding or is not installed in a central location.
• The cold is “wet” rather than “dry,” as in proximity to an ocean or the Great Lakes.

The following chart correlates thermal mass and fuel load:

Thermal Mass and Fuel Load

1. Average value; core is hotter, skin is cooler (300 x 0.23)
2. The bottom layer and benches are not sufficiently warm to count as thermal mass. Storage time: 21 hours; firing time: 3 hours.
3. Net energy yield of one pound 20% residual moisture cordwood combusted with 90% efficiency.

SI Equivalent Conversion Factors: 1 KW = 3,412 BTU 1m² = 10.76 sq. ft. 1 lb. = 0.453 kg