Hi there, I am interested in installing a direct exchange (DX) GSHP in a vertical borehole in my place. I heard that installers braze the U-bend at the end of the copper tubes before they insert it in the borehole. Should I be worried about leaks, especially at high pressures? Are the seals reliable for conventional GSHP refrigerants? Are they reliable for CO2 refrigerant which requires higher pressures??
Linked to that, I have a theoretical question (sorry I am not an expert): let's imagine that the ground loop of copper tube in the ground is somehow seamless and perfectly sealed. Would that mean that we could apply higher pressures to the refrigerant and hence get a higher COP fro the pump, or is this inexact?
Thanks for your help
Fabien