I've had dozens of suggestions on the sizing of my geo loop. I'm going to run a 2-ton heatpump, single pump non-pressure flow center, and 3/4" tubing, 2 runs of 700 feet each. They'll be buried at 6', in a single trench, 16" apart, 325 feet 'out', and a return trench 325 feet back. We're in Kansas City, moderate winters, hot summers. Mostly moist clay, very few other soil features. Would you do a 2-loop horizontal for 2 tons, or go a bit extravagant and do 3 loops? I only need 6 gallons per minute flow, that would seem easy with this type of setup. One last quesiton: I saw some type of device that allows HDPE pipe to penetrate a concrete foundation, and using bolts, the device expands on the core hole, and expands to hold the hdpe pipe, and thus seal the hole from leaks. I can't remember where I saw these little things. Ideas?