Ground Source Cooling - dig it
Ground source cooling is something you get right along with ground source heating, so you enjoy the benefits whether you want it or not. See the discussion of ground source heating if you aren't familiar with the technology.
Cooling your home using ground as the source means the same 50 degree temperature soil that heats your house in the winter can be used to cool your house in the summer. Instead of extracting heat from the soil, this approach to cooling dumps heat from the house to the cool soil that absorbs it.
This energy saving tip requires a substantial investment, but it is probably a good option for someone that is considering new construction on a few acres of land.
If you're not putting in ground source heating, then you can do what I plan on doing - trench underground to create a long heat sink, perhaps 2,000 feet in length, then connect that with a pumping system to a "water to air" heat exchanger in the furnace air plenum.
When you recirculate your furnace and pump water through the underground piping, the air transfers heat to the water in the heat exchanger, and that gets pumped out into the heat sink to release the heat to the soil. The returning water is much cooler and therefore reduces the temperature of the air that passes through the heat exchanger and back into your house.
And, there you have it, air conditioning with a small pump and furnace recirculation. There's no need for a compressor unit and refrigeration lines.
Done with Ground Source Cooling, back to Ways to Save Energy