NOVELTY - The system (1) has a sub-surface geothermal heat exchanger arranged within a well (20) and including an uninsulated, larger diameter vapor line (2) operably coupled to a vacuum-insulated, smaller diameter liquid line (3). The system includes a compressor (7), an accumulator (14), an interior air heat exchanger, an interior water heat exchanger and an oil separator (10) including an efficiency of 98 percentage. An additive is arranged in the subsurface geothermal heat exchanger and prevents compressor lubrication oil (12) from adhering to an interior surface of the vapor line and liquid line.    USE - Direct exchange (DX) geothermal refrigeration cooling/heating system i.e. reverse-cycle DX geothermal heat pump system (claimed).    ADVANTAGE - The system operational efficiencies can be increased when avoiding a short circuiting effect between a cooler liquid phase refrigerant line and a warmer vapor phase refrigerant line within the well/borehole. The system reduces well depths, well casing and well grouting costs by the system operational efficiencies, thus reducing system installation costs, and hence optimizing geothermal heat transfer of the system in an efficient manner. The system operates liquid refrigerant changes phase back into a vapor and travels out of an air handler into the accumulator to prevent liquid phase refrigerant from entering and slugging the compressors. The system enhances heat transfer abilities below the surface and reduces excavation and grouting costs, thus improving overall economic viabilities.    DETAILED DESCRIPTION - The vacuum is pulled between a smaller size liquid phase refrigerant line and a containment pipe that is comprised of polyethylene.    DESCRIPTION OF DRAWING(S) - The drawing shows a schematic side view of a DX geothermal refrigeration cooling system.    DX geothermal refrigeration cooling system (1)    Uninsulated, larger diameter vapor line (2)    Vacuum-insulated, smaller diameter liquid line (3)    Compressor (7)    Oil separator (10)    Lubrication oil (12)    Accumulator (14)    Well (20)