Typical stuff that makes sense. If can bury a couple 1" black plastic pipes approx. 3' deep and you have a good stream near by. Using a radiator or transmission, heat pump cooling coil laying in the bottom of the stream. Hook the pipes (2, a feed and a return) to it. Run the pipes to your dwelling with a solar circulation pump. Use another coil or radiator hooked to the pipes and a solar fan. Put the fan behind the coil. This keeps temps. inside comfortable. It may be a little slow to cool down. But, in a short period of time it will work.
What is the temperature of the ground about 3 feet deep?
Throughout most of the U.S., the temperature of the ground below the frost line (about 3 to 5 feet below the surface) remains at a nearly constant temperature, generally in the 45 ° -50 ° F range in northern latitudes, and in the 50 ° -70 ° F range in the south.
