I have two geothermal systems to heat and cool approx 5,000 sq. ft. I am generally happy with the system but often wonder if it could be better. I have browsed this forum extensively both for advice and just plain old knowledge. A couple of things I have learned from this forum, and from my own experience, is that good design is crucial and that there is a significant difference between a conventional heating pro and one who specializes in geothermal heat. Having said that, when it comes to radiant over-floor heat there are several ways this can be accomplished. One method utilizes PEX tubing with metal conductor plates. There are two systems that I am aware of; Uponor Quik Trak and Eagle Mountain Radiant Max. The Uponor system has the metal plates under the furring strips while Radiant Max has the plates over the furring strips. I am wondering which system is more efficient. It seems to me it would be more efficient to have the conductor plates as close as possible to your flooring. On the other hand I recall a comment, I believe it was from Mark Curtis, that said a consumer sees insulation while a 'wethead' sees thermal mass. Is the Uponor system better because it provides more thermal mass or is it the 'lesser' system because there is more insulation?