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Heat Pump using PEX tubing
PEX tubing for a geoexchange would be overkill and would be less efficient than regular Schedule 40 polyethelyne pipe. It is essential that the sections and U-Bends are welded with a fusion welding method to ensure that the piping is properly joined. The PEX pipe would be appropriate for Radiant Floor heating with the geothermal source and can be controlled to deliver 80-120 F forward line temps to the floor, without the need of a mixing valve. I have done these systems over the last 18 years with excellent performance, but the key is proper design and layout.