I've recently become aware of the existence of 'hybrid water heaters' which use a heat pump to heat the water in the tank. The thing that is appealing to me about this is that the water heater also works as a dehumidifier. That should, at the very least reduce the need to run a dedicated humidifier and are supposedly even cheaper to run than gas heaters (this probably depends on the cost of electricity and gas)
The examples I've seen all use an electric resistance heater as a backup which is really expensive to run. Are there hybrid water heaters that have gas backup? I've seen some discussions about using a tankless heater to augment the hybrid heater but even if that works, it's a lot of up front cost.
Do such units exist? If not, is there a something about this idea that wouldn't work or is it just that there's no demand or perceived demand?
For context, I've been watching the usage on my dehumidifier for the last 65 days and it's used about 170KWH. This is probably the highest demand period for that, though.
Best Answer
The problem I see is that a gas water heater has a big pipe/flue running through the center of it which takes away a lot of room that the hybrid system probably needs. It also vents very hot gas out of the top which is where the compressor is mounted in a hybrid. The electric backup elements are tiny in comparison and just need to stick into the side of the heater. People with gas, which is normally cheaper than electric, don't have as compelling of a reason to choose a hybrid heater, so I doubt there is much demand.
So, very complex and low demand... Probably doesn't exist. I've never seen one.