I have a 2.5 acre lot in Ontario. I intend to use geothermal heat but I am a bit confused about what would make the best system.
Given the choice how would other members do it? Horizontal loop, vertical loop or open loop? If I went for the open loop I have to drill to about 170".
Also I was wondering if I went with the open loop system could I use the same well as the water supply for normal houshold use then I only neeed one other well for dispposal? Also how deep does the disposal well have to go?

I see you haven't gotten any responses yet, so I'll give you mine for what it's worth.

From discussions I've had with others, and my own experience in costing wells, it seems like the only time an open loop system is the best choice is if you need to drill a well in the first place for domestic water. But you'll have to have a good producing well to serve both domestic and heating. Research the issue of required water quality to keep the equipment operating properly. You need good water for the heat pump, as good or better than for drinking.

As for disposal well depth you'll need to contact the folks who have jurisdiction over ground water permitting, quality, etc., in your area. They may require you to inject back into the same aquifer you take it from. Then again, you may be able to use drain field.


Another option to look at is direct exchange heat pumps. You don't need as many feet of ground loop for them.

Thanks for your reply dmaceld.

As it happens I do need to drill a well in the first place and it is gonna cost plenty because the surrounding neighbours have had to go 150 - 200'. Thats what got me thinking if I could just use the same well for the heat source. The neighbours tell me that they get good water and plenty of it but of course that could mean anything. I'm thinking that the best thing I could do is to get the well drilled well in advance of construction, test for quality and volume and then make decisions.

I take it your project time cycle will allow this. If so, I think it's a good way to go. Nothing lost since you have to drill anyway, and maybe a lot to gain.