Proper use for heat pump in cold weather?

[fmors]

Originally Posted by Cofga

Another option is a hybrid system like we put in this spring. It has a high efficiency heat pump and a 95% efficient gas furnace instead of the electric furnace. The heat pump cools in summer and in winter it operates down to 35 degrees. At 35 degrees the gas furnace kicks in and you can really feel the difference. The initial cost is higher than the conventional systems but because you use the heat pump in its most efficient range and the gas furnace when it is most efficient it saves as much as 30% in the long run. We also did a 2 zone installation--one for the upstairs and one for the basement. We keep the upstairs at 68/65 day/night and the basement stays at 60 unless we're going to be doing something down there. However there usually is enough heat transfer from upstairs that the heat in the basement rarely comes on.

We have gas logs in the fireplace that got a lot of use last winter but we've hardly used them this year--the gas furnace really keeps it warm in the house now. When we bought the house the Carolina room was unheated but we renovated it over the summer and added a small wall hung, vented gas heater. Having natural gas is a great option to look for in a house since it is much cheaper than electrical resistance heating and less than heating oil or propane. And once the temps drop below about 35 degrees it is even more efficient than a heat pump. The only problem is you have to have a pipeline running through your neighborhood so that rules out gas in outlying areas.

I have the same exact heating system and could not be happier. The only difference is we live in the country and have propane instead of natural gas.

[Cofga]

Originally Posted by fmors

I have the same exact heating system and could not be happier. The only difference is we live in the country and have propane instead of natural gas.

Yep, my favorite aunt had her coal furnace removed several years ago and put in a hybrid heat pump/propane furnace and was real happy with it. When you do the numbers even though propane is more expensive than natural gas the combination with the heat pump still works out cheaper in the long run.