Reply #16: a friend installed this in their new house...

[ret5hd]

probably aprox. 2200 sq ft.

(i might be wrong on somee details, but you will get the idea)

what the system consisted of:

4 holes bored 260 ft deep in his back yard, each 3-6 inches in dia. (i didnt seee thee holes, he described theem with his hands)

each hole then had a loop of flexible pipe lowered in it, theen the hole was filled with sand.

water flows thru the pipes in each hole. the other end of the pipes is connected to a heat exchanger in the attic. the ground stays at a steady 60 deg. F, heating or cooling the water, depending on the season.

the house has a "heat pump" installed, which may seem underpowered, but since you are not exchanging heat with -20 deg air or +100 deg air, but rather with 60 degree water, it is very adequate.