Found this on a site that has a lot of other cool heat reclaim products for pools and domestic hot water, even a solar panel powered minisplit.
Air Conditioner Water Heaters | AC/Heat Pumps That Make Free Hot Water | HotSpot Energy LLC
A factory made version of what some here have talked about doing, and done. Competition to the super expensive Fujitsu? I believe was the brand, water heating minisplit possibly? It says up to 100 gallons of water a day, and using their stats thats 4500 btu/hr into the water. I bet if you put a bigger water HX in you could put more into water and less into the air.
Just some food for thought.
Adam