Abstract: A one-piece, unitarily formed compact geothermal heat exchanger comprises a one-piece body having an external screw-type configuration including a cutting tip and a spiral thread extending from the cutting tip upwards towards the top of the body of the heat exchanger. The top face of the body includes a working fluid inlet and a working fluid outlet, each of which are in communication with an internal continuous helical channel inside of the one-piece body through which the working fluid travels during operation to transfer heat energy between the working fluid and the ground. A compact geothermal heat exchanger having such configuration may be installed by screwing the heat exchanger into the ground to the desired depth, without requiring prior digging or other excavation of the ground surface. The compact geothermal heat exchanger may then be connected to a conventional geothermal heating and cooling system for geothermal heating and/or cooling of a space, such as the interior of a building.