Nice work! I've got a broken (leaks) 24,000 BTU unit and have been thinking of using it with an Ebay heat exchanger.
24KHS72 - Sanyo 24,200 BTU Wall Mount Heat Pump Air Conditioner Kit
Want to make some domestic hot water.. (Hate burning oil for showers etc).
It's somewhat modern, but I may be able to use the Test mode jumper, and force it to run.
http://i46.photobucket.com/albums/f1...L/Fall2010.jpg
Your pool heating project has give me some fresh ideas..
Thanks,
Rich