This study was designed to experimentally look into some of the advantages and disadvantages of DXGC designs. A laboratory study of a DXGC heat pump system was performed. The results of the laboratory tests indicated that a DXGC can absorb from, or dissipate to, the ground at least twice as much heat as conventional plastic tube ground coil heat exchangers. Some of the above-mentioned concerns were also studied during the tests. A set of qualitative general design guidelines was derived from the test results and observations are presented.

KEYWORDS: soil heat exchangers, experiment, heat pumps, soil heat pumps, laboratory testing, heat loss.