I have been living with my WaterFurnace for 2 months now. The meter reader couldn't get in my gate last month, so I will be able to give you some utility costs in a couple of weeks. Here is what I do know...I am cooling about 4500 sq.ft. with lots of windows and doors with a 6 ton unit. It has been 100+ degrees here for the last two weeks, and I can make it as cool as I want inside.
My house is about 220' from the 6 acre pond, and I am running a closed loop. There is 3000' of 1 1/2" plastic pipe coiled up on the bottom of the pond. The coils are tied up on a "sled" about 8'x14' that the guy floated out and sunk. I have two tiny little pumps, no bigger than your fist, that circulate the water through the loop. The system cost, including ductwork and everything was a shade over $20k. I'll let you know if it was worth it when I get the bill, but so far I am very happy with the system.
