Wow, my heart really goes out to someone who builds an 8600 sq ft house and then complains about the utility bills.

There's a lot variables that go into such a complex system - there's also the issue of utility rates, weather, etc. My guess is that there aren't a lot of contractors in your area that are competent to work with this equipment. Before you go alienating any of them with a lawsuit (and word would travel fast), I would try to work with them to get the system working properly, if it's not already.

Just some general commentsÂ

First of all, you may not have enough capacity. Was a load calculation done? Second, your power consumption may be completely normal. See what these units consume per hour by reading your owners manual specifications and multiplying by the approximate number of hours per day they seem to be running. Third, you may not have enough ground loop per ton, 50ft/ton may be too short! I would have drilled 100ft/ton. But then again, if your compressor(s) is (are) not locking out on high-pressure your loops may be OK, albeit not very efficient. You are however, sinking a lot of heat into the ground over a very short distance (50ft)!

I would NEVER install 50ft ground loops for DX Â and IF I did, I would have the client sign a notarized waiver stating that I bear no responsibility what-so-ever - that the client was warned that this might not work, that he wanted to proceed at his own risk!

One circumstance where this could work (50ft/ton) is in a case where we KNOW that there are fissures in the ground bringing high volumes of water in direct contact with the copper ground loops AND that the boreholes were backfilled with a coarse silica that would allow the water to flow though the boreholes contacting the copper ground loops directly (DX Â Direct Exchange).

Even then I would insist on 100ft per ton - minimum. That way at the very worst you would still have an efficient system - even if there were a change in the hydrology.

SR