I am getting ready to replace a system in my home. Presently I have a heat pump with a gas furnace backup, both about 20 years old. For the new system I am seriously considering going to electric heat backup instead of gas.
My thinking is that with gas backup, I can't run both heat pump and gas simultaneously, so once the temp drops below the point where the heat pump can heat the house by itself, then I am never using the heat pump. Whereas with electric, I can run heat pump and electric heat together, so I can use the heat pump down to a much lower outside temperature.
My utility cost is about $1.10 per therm for gas, and $1.45 per therm for electricity.
Does this make sense?
Is there such a thing as a system that uses all 3 fuel types? In other words use the heat pump as the primary, electric strip for additional heat down to a certain outside temp, and gas heat for very low outside temp and during heat pump defrost cycles?