Some years back, Mother Earth News (?) did an article on how to air-condition your off-grid home by pumping air through 6" burried tubes 8' or more in the ground, as differential in the dirt temps that deep is significant in the heat of summer. The same physics would apply if you pumped your pond water through a series of tubes under-ground, though personally I would use hundreds of feet of coiled 1/2" poly in lieu of the bigger stuff they suggested for home-made air-conditioning. Desparate times take desparate measures...
Last edited by Double Camp; 09/07/11 10:15 AM.
