Conference Proceeding published 2008 by ASHRAE
Written By Michel A. Bernier, PhD, PEng; Antoine Chahla, PEng; Patrice Pinel
This paper examines thermal interaction among boreholes in geo-exchange systems with vertical ground heat exchangers. Borehole thermal interaction is caused by ground thermal imbalances and results in long-term ground temperature changes that can have a significant impact on borefield sizing and heat pump performance. Long-term temperature changes are quantified in this paper using the concept of temperature penalty, Tp, which represents an effective increase (or decrease) of the undisturbed ground temperature to account for borehole thermal interactions. A comparison is made with current values of Tp found in the ASHRAE HandbookâHVAC Applications (ASHRAE 2003). Finally, a general correlation, adequate for engineering calculations, is
proposed to estimate Tp.
Units: SI
Citation: ASHRAE Transactions, vol. 114, pt. 2, Salt Lake City 2008
