Abstract: One embodiment of a compact, closed loop geothermal energy exchange system, which is used in conjunction with geothermal heat pumps to heat and cool interior spaces, is provided. Conduit (2), through which process fluid flows, is configured within a containment tank (1) in a manner that optimizes the contact between the conduit, an interior soil mass (4) and the soil mass exterior to the tank. Water from a source within the geothermal zone of the earth is introduced, when necessary, to the interior of the tank by means of a temperature regulated valve (not shown) and pipes (3) located at the top of the tank. The interior soil mass, the exterior soil mass and the water, in combination, will regulate the temperature of the process fluid, thereby providing optimum operating fluid temperatures for geothermal heat pumps. A means of collecting the water and removing it from the tank is provided by a perforated pipe (6) connected to a water overflow chamber (5).