[stevehull]

Sam - all you need to know is what is the maximum BTU load your heating system must provide on the coldest night for your specific home. A BTU is a BTU - about the heat output of one lit match.

The heat source (BTUs) could be resistance heating, propane, oil fired, air source heat pump, or ground source heat pump (GSHP) - or solar hot air collectors.

Each of these, when run at 100% has a heat output rated in thousands of BTUs (kBTUs). Sometimes the output is rated in tons where 12 kBTU = 1 ton.

The key is to find a cold night, run the heater with the thermostat on 65F, circulate air well and record the cycle time in the early AM when everything has reached a steady state (typically takes 6-8 hours). The resistance to heat flow through your envelope can then be easily figured as kBTU per heating degree day.

Then once you know how many kBTUs you need, we can advise what heat source to use that is best for you. Some like to use wood, and that heats you at least three ways (chopping, carrying and then burning) . . . .

I have gone with GSHPs and also have a small Vermont Castings wood stove when I want to see flames - or feel the need for direct radiant heat.

Record the data . . . . .

Steve