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Something that readers may not know is that they are now heat pumps on hot water heaters. An added benefit is that the fan on the heat pump will exhaust cold ai

Something that readers may not know is that they are now heat pumps on hot water heaters. An added benefit is that the fan on the heat pump will exhaust cold air. That might be a benefit for some folks!

nimajneb 4y ago
Can you clarify what you mean? There's only ~2 fans in my system, the one on the heat pump outside (looks like an AC unit) and the one in the air handler in the basement. To me sitting in my dining room this system is no different than any other forced air system.
- ars 4y ago
  The air for a hot water heat pump could be entirely indoor air, the entire unit is located inside. Unlike an A/C which is split, with the compressor located outside.
- mikeyouse 4y ago
  He's saying that instead of a gas or electric hot water heater - you can now buy a heatpump version. It works the same as a normal heat pump, but it takes ambient air in your basement or garage or wherever, and then moves that heat into the water which provides a slight cooling and dehumidifying effect for your indoor climate. They make a lot of sense in the US South. https://www.energy.gov/energysaver/heat-pump-water-heaters https://www.energy.gov/energysaver/heat-pump-water-heaters
  - bombcar 4y ago
    To be precise the heat pump water heaters are electric - they just use latent heat in the air around them as much as they can, but they'll fall back to electric when that isn't enough. They also cease working when the power is off, of course.
ars 4y ago
They exist, but are really only good in the southern part of the US. In the north the incoming water is cold which really slows down the hot water creation (recovery) rate, and that cold exhaust then needs to be warmed up by the heat. If you have low usage (i.e. less than 40 gallon/day of hot water) you could get away with it, but that's two showers - so if your usage is more than 2 showers per day I would avoid them. But in the south they are a much better choice, since the recovery rate is much better and the cold air helps with A/C.
fghorow 4y ago
I have (air source) heat pump water heaters in two different basements. (Don't ask.) A big win for me is that I no longer need to run a dehumidifier in those basements. The cold air output from a water heater alone is good enough to keep the humidity down. Again, YMMV.
pkaye 4y ago
There are also heat pump dryers. Requires no exhaust ducts, reduced energy consumption but longer drying time.

nimajneb 4y ago

Can you clarify what you mean? There's only ~2 fans in my system, the one on the heat pump outside (looks like an AC unit) and the one in the air handler in the basement. To me sitting in my dining room this system is no different than any other forced air system.

ars 4y ago
The air for a hot water heat pump could be entirely indoor air, the entire unit is located inside. Unlike an A/C which is split, with the compressor located outside.
mikeyouse 4y ago
He's saying that instead of a gas or electric hot water heater - you can now buy a heatpump version. It works the same as a normal heat pump, but it takes ambient air in your basement or garage or wherever, and then moves that heat into the water which provides a slight cooling and dehumidifying effect for your indoor climate. They make a lot of sense in the US South. https://www.energy.gov/energysaver/heat-pump-water-heaters https://www.energy.gov/energysaver/heat-pump-water-heaters
- bombcar 4y ago
  To be precise the heat pump water heaters are electric - they just use latent heat in the air around them as much as they can, but they'll fall back to electric when that isn't enough. They also cease working when the power is off, of course.

ars 4y ago

They exist, but are really only good in the southern part of the US. In the north the incoming water is cold which really slows down the hot water creation (recovery) rate, and that cold exhaust then needs to be warmed up by the heat. If you have low usage (i.e. less than 40 gallon/day of hot water) you could get away with it, but that's two showers - so if your usage is more than 2 showers per day I would avoid them. But in the south they are a much better choice, since the recovery rate is much better and the cold air helps with A/C.

fghorow 4y ago

I have (air source) heat pump water heaters in two different basements. (Don't ask.) A big win for me is that I no longer need to run a dehumidifier in those basements. The cold air output from a water heater alone is good enough to keep the humidity down. Again, YMMV.

pkaye 4y ago

There are also heat pump dryers. Requires no exhaust ducts, reduced energy consumption but longer drying time.