I would go with the most efficient system, which in this case would be the Waterfurnace Series 7. I would want to know if the flow center will be variable speed as well and if so how will it maintain âÂÂturbulent flowâ at the reduced speeds.

Also note that the published efficiency specs will not be met without a properly designed, installed and commissioned ground loop. EVERY detail is important!

Cost is dependent not only on equipment but size of HDPE pipe, depth of borehole, number of boreholes, parallel or series configuration of boreholes, indoor or buried headers, type of header, on and on and on.

Mistakes in the ground are very expensive to repair.

DonâÂÂt assume anything; become your own expert!

IâÂÂm sure youâÂÂll love your geo system.

SR

Here is a link that might be useful: International Ground Source Heat Pump Association at Oklahoma State University

Thanks fsq4cw. Glad to hear that it's the ground installation that matters most. I have an IGSHPA-certified well driller who will install the loops. Not feeling quite as confidant about the contractors selling the equipment, so I'm trying to work a lot of it out myself.

Why don't you think anyone ever mentioned Direct Exchange (no wells, copper piping, etc.) to me? This forum was the 1st place I had even heard of it. Seems like it might be most efficient?
Thanks again!
T

Very few installers are familiar with proper DX installation. At this point I would not advise installing DX even though I know it can work very well. We have a Nordic DX-45 Direct Exchange geothermal heat pump that is 10 years old, has never needed a service call and has never broken down.

As great as this system has been if I were to do it over again today I would install the Waterfurnace Series 7 all variable speed. This type of conventional ground loop (liquid) will be easier to diagnose and deal with if there is a problem. I would install the headers within the mechanical room for the same reason.

Shana Tova (if thatâÂÂs in order)

SR

fsq4cw, just wanted to say thanks once again. You've been super helpful here, and in your many posts on other threads that have taught me much about geothermal. Checking the price difference on the WaterFurnace 7 vs 5 now. Do you think this issue of "formicary corrosion" of the coil, causing refrigerant to leak, is specifically a WaterFurnace problem? or do they all have this potential problem?
Thanks again.
T

We are also looking at Waterfurnace series 5 vs series 7 and curious whether you decided to go with the 7. We have a not-quite 10 year old single-stage climate master that has been nothing but trouble (pumps, coil, condenser) so are looking to replace it.