Subsurface Thermal Energy Storage for Improved Air Conditioning Efficiency
Technical Report,01 May 2010,01 Dec 2016
Clemson University Clemson United States
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This project involved a field demonstration of subsurface thermal energy storage for improving the geothermal heat pump air conditioning efficiency. Many buildings in the U.S. are cooling dominated with relatively low heating demands. When these buildings are cooled using conventional geothermal heat pump systems, undesirable heating of the ground may occur. This demonstration was performed at the MCAS, Beaufort, SC, where several buildings with geothermal heat pump systems were exhibiting excessively high ground loop temperatures. These buildings were retrofitted with dry fluid coolers that were operated to remove excess heat from the loops when outside air temperatures were favorable, especially in the winter. Operation of the coolers substantially reduced the ground loop temperatures. An analysis of the system performance shows that using dry fluid coolers for wintertime cooling of the geothermal ground loops can eliminate loop temperature increases over time, and improve the system efficiency over conventional geothermal systems.