I haven't but high chlorine levels is very hard on copper pipe. Don't know of a home unit but look at commercial heat exchangers.

Sounds like a great idea. If you learn anything, please post it.

Chemicals are the only problem with this system. Dectron pool units are desidned to Heat,cool, and dehumidify an enclosed pool. They are air source units that use heat rejection for the Air Conditioning and can also ise the inside coil for dehumidification
basically 2 condenser coils. You would need a really large unit to effectivly accomplish what you want,.....Not practical.

Correction... I have seen a unit that will work to heat the pool/House. Dectron Is the name. They use these units at the Holiday Inns In Buffalo.