I've heard this statement too many times: "we always throw in an extra loop". Correct me if I'm missing something! Number of loops and size of pipe is determined primarily by reynolds number (to maintain turbulence). If someone is doing 3/4" loops with one ton per loop on a 3 ton system, that's 3 gpm per loop which is fine, but then they go and throw in another loop for a "safety margin" and end up with 2.25gpm per 3/4" loop (laminar flow). (Based on 25% propylene glycol at 30* EWT, min flow should by 4.43 gpm in 3/4" pipe, no?) So I guess my question is: Will the extra pipe in the ground make up for the lack of turbulence? For starters, lets disregard the cost effectiveness of this approach and look solely at the functionality of the loop field. Thanks folks!