In commercial installations, an underground heat exchanger and a fluid-pumping or circulation system are combined with packaged geothermal heat pumps. The heat pumps are placed throughout the building to provide multiple temperature-controlled comfort zones. GHPs can be configured for single rooms or zones with individual circulating pumps and ground heat exchangers. In large installations, the system consists of a ground heat exchanger with a single pumping station serving multiple heat pump units. In addition to saving money, GHPs provide very comfortable heating and cooling.
Customer satisfaction ranks among the highest of all heating and cooling systems.
Building owners and users can simultaneously heat and cool, provide many separate comfort zones, heat and cool selectively, and operate with very little down time. Typically, GHPs do not require roof-top units, which are undesirable aesthetically and require roof penetrations, with the potential for leaks and future maintenance. The work has targeted several areas of GHP technology, lowering the cost of ground heat exchangers, and developing advanced design software. Hansen chose the system based on a recommendation from Duluth-based utility Minnesota Power, which provided technical and project management assistance and helped defray the cost of the mechanical design. If the ESCO can integrate the HVAC design into the building plan early in the design process, the rate of return can be even better.