Hello, I have been reading and taking notes here for a while and think it is great that there is a community out here to support and direct others when considering a Geothermal system, so thanks in advance. I was hoping that some of you with some experience designing and/or installing Geothermal Systems with a closed ground slinky loop would look over this basic design and let me know if we are on the correct track. The house is 1200 sq ft located in Charlotte, NC. Ground temp at 5’-6' depth is 62 degrees year round. I need about 2.2 -2.5 tons to efficiently cool the home. An approximate numbers I have observed is: 100 ft of trench (3 ft wide, 6 feet deep) = 600-800 linear ft of pipe = 1 ton. I have approximately 275 linear feet of trench space available in soft damp clay beside a small stream. This is what someone noted: “Each loop of the slinky is 3’ diameter. The circumference of one loop = ∏ x D = 3.1415927 x 3’ = 9.42 ft is the length of pipe for one complete circle (or loop) of the pipe. At 18” pitch, it means you have need two loops of the slinky for every 3’ feet of ditch (18” x 2 = 36” = 3’). Two loops = 2 x 9.42 ft. per loop = 18.85 ft. of pipe for every 3 ft. of ditch. So 18.85 / 3 = 6.28 ft. of pipe used for every 1 linear foot of ditch. So you have 275’ of ditch x 6.28 ft. of pipe used in the slinky = 1,729 ft. of pipe used in the total slinky design to fill 275 of ditch with 18” pitch loops at 3’ diameter per loop” The way I see it at a pitch of 18, every 3 ft is a loop and a half or 14.5’ of pipe, or 1 linear foot is 4.5 ft of pipe. My first question is, Which of these is correct? And if incorrect, what pitch or formula would I use to fit 1800 linear ft in 275 ft of trenches? Next question does 1800 pipe feet of loops (not including supply and return footage) sound like enough to work with a 2.5 ton system. Another design question I have is serial loops VS parallel loops. Example: Three 600 ft loops parallel to each other with a header using ¾” HDPE Or One continuous 1800’ loop without a header using 1” or even 1.25” HDPE. Which seems a better route to go? I have heard arguments for both designs based on pressure drop/flow rate/ equal H20 distribution/ energy exchange/etc. One of the “kits” sold for a 2.5 ton system suggests 3- 600 ft runs of ¾” HDPE with header and a ½ hp flow center pump. I’ve been told that a larger diameter pipe in a continuous 1800’ loop would give the H20 more time to exchange with the ground, because the flow rate would be slower and more evenly distributed over the continuous loop. Another factor to consider is that the three parallel runs cannot be the exact same length. Any advice or opinions here would be much appreciated. Thanks for your time. PS I attached a picture of the area I have to work with.