illustrated in fig1 the present invention may utilize a ground loop 230 such as is illustrated uncovered in fig4 the ground loop comprises a length of pipe or tubing such as copper tubing which for purposes of compactness may be arranged in the form of a sinusoidal coil as shown the loop 230 is buried in the ground to a depth of approximately eight feet 2 44 m and to assure good thermal contact with the ground a thin layer of sand may be interposed between the ground and the loop 230 the purpose of the thin layer of sand if used is to allow settlement or shifting of the ground to occur without loss of a good thermal exchange between the ground and the loop 230 as schematically illustrated the loop 230 will have an inlet tube 232 and an outlet tube 234 extending from the opposite ends thereof and upwardly through the earth for attachment to the heating and cooling system already described with reference to fig1 thus the inlet tube 232 would be connected as an extension of the return conduit 164 illustrated in fig1 and the outlet tube 234 would be connected to a suitable pump mechanism not shown.