When the DX Geothermal system is in heating mode, it simply takes heat from the earth, and puts it into your house. The refrigerant loop that runs through the ground is colder than the surrounding earth, so heat is absorbed from the earth into the refrigerant fluid. Hot goes to cold.That refrigerant fluid is cycled through the ground loop and into heat pump, where it is put through a compressor, which pressurizes it, and in turn, raises its temperature even more. That heat from the refrigerant loop is then transferred to your home distribution system either by an air handler (forced air systems) or a water heat exchanger (radiant heating). The heat from the refrigerant goes to the cooler house.