This has been a dream of mine too. My thinking is to run a short geothermal loop under my parents crawl space about 48-inches deep. It's cool all the time and slightly damp, but not wet.

Love the back-hoe and the industrial level of expertise on this project. Never seen anything like this done before. You sir are cutting edged next to the guy who heated his home with base board water heated by his four F@H machines.