Started getting pipes in the ground today. Doing 4 horizontal loops, 700 ft, non pressurized, DIY manifolds, and added 2 more loops for future addition. Replacing a 3Ton Trane air unit after 18 years. Upstairs unit is a 2 ton, and probably replace it in the near future. While I had the project going, I added 2 700 ft loops and manifold for if and when the upstairs HP dies. Built my own manifolds, added pressure gauges to all four. More posts as the project progresses. Several people responded to some other threads, I appreciate them taking their time and answering my questions.