i live in south east saskatchewan canada, i think the ground temp is in the 50's here, i am putting 2 heat pumps in, a 3-ton forced air with a desuperheater, and a 2 ton water-water to heat my basment floor and on rare occassion my garage floor. my house is a well isulated 1640 square foot single level, tripple pane argon low windows and the works.  my geo installer wants to put a '4-ton' loop in, 800 feet of verticle holes, and one circulating pump, he uses a closed loop with a open end, a small insulated tank with a grunfos 1/2 horse 10SQ submersible, this pumps through the loop then the heat pump then back into the tank. the tank is the size of a small water softener tank. he said we only need one loop system because the 2 heat pumps will not be running at the same time very often. my driller showed up yesterday (finally! said he was gonna be here in May) he did a test hole and dropped his first 100 fett in 20 minutes, said it was tough going after that, so he plans on 8 100' holes. said something about 'glad handing' the holes together, not sure if that is parralel or series. anybody see any problems with a set up like this?