I am building an addition to a house that i am remodeling. and i am deciding if a heat pump is worth purchasing. I have read that i will need a secondary heat source and the payback for a heat pump will take 30 years if it will ever payback. I live in western pennsylvania where it gets colder than 32 degrees most winter and some fall days. Natural gas is not available where i live. so m options are electric furnace, heat pump, or pellet stove. do i need a secondary heat source with the heat pump? and is it worth getting the heat pump? all comments and suggestions with information is greatly appreciated thanks!
Conventional wisdom has said to avoid HP in cold climates because they lose their efficiency at low temps (40k btu is only putting out 20k @ 30F, etc.). However, Carrier now sells their "Greenspeed" line of heat pumps that can maintain efficiency down to much lower temperatures. Note that you will still need additional BTU in the home during very cold weather. You really need to study the conditions in your area and home:
- Heating and cooling load of your home (perform a Manual-J calc). The house down the street could require a completely different HVAC solution... it really depends on your home's construction. Free and/or cheap calculators are available online. I used hvac-calc (~$50 IIRC) because it had all the R-values and regional information incorporated in the tool. AHRI has a free Excel spreadsheet but it takes more work.
- Cost of utilities per BTU (the efficiency of the equipment will need to be factored in)
- Any local kickbacks from a state agency for efficient appliances (energy trust, etc.).
You should not listen to blind recommendations like "get a propane furnace". Do the measurements and look at the equipment options. Once you have your heating and cooling load for the home you can look at the technologies + cost of utilities + cost of equipment and arrive at an educated decision. A new HVAC system is $$$$... make sure you're installing the right stuff!