My neighbor has a 6 ton and 3 ton geothermal systems. His loop are buried 6' in the ground under his yard. His house is 7000 sq ft. He says his worst bill in the 2 years he has lived there was $200.
My dealer told me the pond loop is by far the most efficient, and it makes sense, that it's easier to transfer heat from water-to-water than water-to-dirt.
Waterfurnace.com has a lot of info and if you'd rather watch the movie, go
HERE I will be putting in a 6 ton WaterFurnace. The guy says that the pond loop will be about 40' x50'. He says he has seen his loops years later where the pond had been drained and you can't even tell where the loops are because they bury themselves in the bottom.
There is a product called a "Slim Jim" that is just a nice copper radiator that can be set on the bottom or mounted under a dock. They are rated in "tons". I was going to get one until I found that it would cost $2000 more than the pipe loops. They also create more resistance, requiring a larger pump.
