A hydrothermal energy system consists of any system which uses a thermal exchange with the earth: ground water, surface water, heat pipes or tubes. Hydrothermal energy system includes the following:
(A) Ground water to air heat pump - a heat pump which uses ground or surface water as the source when space heating and the sink when space cooling;
(B) Ground water to air heat exchange - a heat exchanger which has one side exposed to ground water and the other side to air for space cooling;
(C) Closed system - a heat pump which uses a stored water unit as the source and the sink. The storage unit must be in contact with the earth and below the frost line. The storage unit must be of sufficient size that it will not freeze solid during a heating season.
Rule promulgated under: RC Chapter 119.
Rule amplifies: RC 1551.20