Hello All- I had a quote done a few years ago for a water-to-water geothermal heating system for my house. At the time they quoted a four ton system, with (4) 600' loops of 3/4" tubing to be buried in the field behind the house, with the headers located in the basement. I was unable to purchase that part of the field- now I will have to run my header pipes (1-1/4") 300' to get to a portion of the field I can use. I realize I will need bigger pumps and will use more electricity, but do you see any other problems with this? I am afraid I am getting too far away from the house- the total distance the antifreeze will travel is 1200'. I was thinking more, smaller loops, but don't want to get too low of a flow. Thanks for your help. John

You can go as far as you want as long as you design for it.

Should not be a problem, you only use a 4 ton system, for what you only need 12 gpm flow. Simply do pressure drop calc and make sure you have the correct circulation pump(s).

A longer loop field will only improve the efficiency because of more heat transfer as long as your flow center/pump is sized for the head pressure of the longer loop.