Ground source heat pump (or geo-exchange) systems, are a very small percentage of HVAC installations in the U.S. A principal reason for this is the cost of the ground loop, usually in the form of boreholes. This presentation describes a multi-source system using dry fluid coolers or solar thermal collectors to go beyond what can be done with conventional geo-exchange. Although a variety of solar assisted ground source heat pump (SAGSHP) systems have been described in the literature in past years, none of these have had commercial success. It is possible that with a more optimum design, this approach could become more cost-effective than conventional geo-exchange systems and thereby become commercially viable.
Gaylord Olson, consultant, Seasonal Storage Technologies
Yao Yu, Assistant Professor, North Dakota State University