[bach-on]

Yeah. I've also considered Geo-Thermal, though I began to think it would be too labor intenisve. I'd suggest you contact someone who builds solar homes - especially a test home. We had one built at North Carolina State Univ. It uses a geothermal climate system. This is still considered a "pilot" project, so I'm sure there aren't too many folks who do this type of cooling. Perhaps the Agricultural folks who do soil testing and keep up with things like "frost lines" may be able to offer advice.

I really don't think a foot down will make any difference. From what I understand, you'll have to go substantially deeper. How deep is an unknown to me. But I'll bet somebody can give you an idea. This is the labor problem. Digging a 100 foot trench three or four feet deep is one heck of a chore, even with a mechanical ditching tool.

Copper in the ground might be the way to go, but you'll probably need to insulate the line as it enters the house. Otherwise, the copper would heat the water, thus offsetting the gain from the ground trip.

I'll be interested to hear how you do this. Please keep us posted.