Heat pump water heater during the winter
 

Hi all!

I have a heat pump water heater in the basement and absolutely love. Had it for about 5 years. Obviously I want to keep it in heat pump mode as that uses the least amount of electricity. In the summer it has the added benefit of cooling and dehumidifying the basement. A win win.

However, my question is what to do during the winter. Should I keep it in heat pump mode, or electric resistance? Heat pump mode will use less energy to heat the water, but also takeup heat from the basement that then theoretically needs to be replaced by my furnace.

I know there's a lot of factors to consider. We do heat the basement somewhat, but not much. I have three vents open down there just to keep the air moving and keep it from getting too cold. We have heat pumps for our main furnace.

Any thoughts?

Thanks!

Just leave it in heat pump mode.

What Mike said. The actual heat transfer depends on a lot, but since you have forced air heating, you're not going to be wasting power. Heat rises, so your forced air will stratify above what comes from the water heater. The cold air from the water heater will drop to the floor and cancel out some of the heat loss through the basement floor. If anything, you will be robbing some energy from the forced air system to heat water. Since this heat came through another heat pump indoors, you're not wasting power.

I think there's a DoE study that shows the impact of a HPWH is pretty minimal, even on homes heated by a heat pump, and that it was decisively preferable to any version of "exhausting the cold air outdoors" or running in resistance mode.

Ok, this is what I've been doing, but always been curious as to what's best. Thanks all for the answers!