In my cellar I have an old not in use dug well that never goes warmer than 50F. I installed 300 ft of 1/2" black pipe, in a roll and installed a 21000BTU heat exchanger designed for auxiliary heat for a truck or tractor or whatever. Purchased at princess auto in Canada( its got a 3 speed 12 volt fan too, perfect for solar) Going to install in line Laing pump for circulation. Closed loop system. Cant see why this wouldn't work. Makes sense. A type of geothermal cooling. Right. Yours should work as well.