[masraum]

Originally Posted by unclebilly

Except that the efficiency of a heating device is much greater than the efficiency of a cooling device.

Everything being equal, it takes more electricity to cool 10° than it does to heat 10°.

A heater is a heating element which is basically a resister with power applied. Water is circulated past the heated element. Requires a heating element and a water pump.

A cooler involves compressing a refrigerant to pressures above 100psi, running it through a cooler, then expanding it through a nozzle to get evaporation (and hence cooling). The pool water is circulated through a heat exchanger where the cold refrigerant cools the water and the refrigerant is compressed again… lots of moving parts, indirect energy conversion, requires a compressor, a fan, and a water pump.

Agreed that the energy required to heat water 10° is the same as to cool it 10° but practically, the energy inputs needed to cut a cooler to accomplish this are probably 2-3X more than a heater.

Right, that was what I was talking about, the energy required (gained to heat or lost to cool). I wasn't getting specific about the method of heating, electricity required, that sort of thing. My thought is that in this area, a solar heater is most common, and I would think that a solar heater could also be a used as a cooler. A quick google search says that a solar heater can be a cooler if it's run at night.
https://floridasolardesigngroup.com/cool-your-pool-with-a-solar-pool-heater/
It works like a radiator.