Any thoughts on the relative merits of a propane furnace vs. heat pump with respect to installation cost, reliability, efficiency? We're building on a ridge in central Maryland. Probably will have 30-40 (??) days per year when the temperature stays below 32.
Without knowing all the details about your specific needs and conditions, my best guess is that propane makes more sense than a heat pump. Here is why:
(1) A propane forced air furnace will likely cost less than 50% of the cost of a heat pump.
(2) With the high number of very low temp. days in your area, the heat pump will have to operate on the 'back up' mode a large part of the time. This will reduce the cost benefit of a heat pump system.
Explanation: A heat pump works best at outside temperatures of 39F or higher. Once the outside temperature falls below +/- 35F a backup heating system assists or replaces the heat pump.
The backup system is often an electric resistance heating system, a much less efficient heating option.
(3) A heat pump requires service every 6-12 month. Most heat pumps require larger repairs every 8-12 years. It is not unusual to find that the maintenance and repair costs of a heat pump are greater than the cost of a new gas or propane furnace.
Note: The propane or gas furnace requires annual service. A good gas or propane furnace should last for 20-30 years without any major repairs.
(4) One reason why a heat pump might be a good idea has to do with the cooling ability of such a system. If summer cooling is a requirement in your area, you might look for a heat pump with a propane backup system. George
Here are a few comments from a reader and a good reminder that energy costs have changed a great deal in the last few years.
I am not sure what Propane or electricity cost where you are but here in Texas I am paying $0.1239 /KWH and Propane cost $2.87/Gallon. If you do the calculations for an 80% furnace you will find that a gallon of propane will produce 72,800 BTU. I calculated that with a heat pump with an HSPF of 9.35 it would cost $0.96 to product the same amount of heat.