Law, Ying Lam E.Dworkin, Seth B.IGSHPA Technical/Research Conference and Expo (2017)2017-03-062017-03-062017http://hdl.handle.net/20.500.14446/49323During the operation of a ground source heat pump (GSHP), the ground acts as a heat sink and heat source in cooling and heating modes, respectively. When the heating and cooling loads are extremely unbalanced, ground temperature can slowly migrate up or down in the long term, diminishing the GSHP system's performance, and eventually causing the system to fail. This failure occurs when the ground can no longer accept or provide more heat for a building. Therefore, a method to mitigate thermal imbalance is needed. Previous studies in the literature examine the effects of borehole configurations in geo-exchange. However, no study has been done to analyze the effects of varying borehole lengths in a bore field. The objective of this study is to examine the effects on thermal performance from changing the length of individual boreholes while retaining the same total borehole length. In this paper, the four centre boreholes in a 4x4 borehole system were shortened and the length of the remaining boreholes was recalculated to meet the total required ground loop length. A 20 year operation was simulated for a school building model with centre borehole lengths of 100 m, 80 m, and 50 m and separation distances of 3 m, 4 m, and 6 m, to study the benefits of shortening the centre boreholes. The results demonstrate that by adjusting the length of the centre boreholes, separation can be reduced.application/pdfIn the Oklahoma State University Library's institutional repository this paper is made available through the open access principles and the terms of agreement/consent between the author(s) and the publisher. The permission policy on the use, reproduction or distribution of the article falls under fair use for educational, scholarship, and research purposes. Contact Digital Resources and Discovery Services at lib-dls@okstate.edu or 405-744-9161 for further information.ground source heat pump systems10.22488/okstate.17.000507Conference proceedings