[ITD]

That makes sense Jeff, of course that is also a sizing issue although not what I was thinking about. The materials and labor for providing a larger loop is minimal once you have the equipment on site, so maybe lot size is an issue. I think a system that uses lake water or wells would not be prone to this. I still think that heat loss before the ground source fluid gets to the heat exchanger plays a part in this also. All of the systems I have researched have the pipes penetrate the surface and have at least a few feet of pipe in open air with just some foam around it.