Edit 1/5/2025: Since I wrote this, I had a new heat pump installed. It’s an air-source, two-headed mini-split heat pump. See Post #2060 for the reasoning.
The “which fuel is cheaper” analysis below needs to be modified a bit, because the “regular” unit I bought only works down to 5F outdoor air temperature. At which, it still runs at COP 2.1 (see below). But below which, it (presumably) does not run. So, where I talk about temperatures of zero, below, assume a better unit than what I actually bought, that actually runs down to zero F.
Original post follows:
In Post #1706, I determined that, for heating my home here in Virginia, it was far cheaper to run my heat pumps than to run my natural gas furnace. That’s based on costs of $1.70 per therm of natural gas, and $0.12 per kilowatt-hour (KWH) of electricity. Like so: Continue reading Post #1716: COP out. Does it ever get cold enough, in Virginia, to make gas heat cheaper to run than a modern heat pump?