Life cycle cost analysis of ground source heat pump system based on multilayer thermal response test

Abstract The purpose of this study was to determine the life cycle cost (LCC) of a ground source heat pump (GSHP) system based on the results of a multilayer thermal response test (TRT). Previous studies by our research team suggested the possibility of significantly reducing the total borehole length, based on the results of the multilayer TRT to identify the partial groundwater flow. In the present study, it was validated that the borehole heat exchangers reduced by the results of the partial groundwater flow could operate with a sustainable performance of the GSHP system over an extended period. LCCs of the GSHP system for 30 years were analyzed in three areas with different climatic and geological conditions. Based on these results, the proposed method demonstrates a reasonable cost reduction advantage compared with conventional TRT analysis. The multilayer TRT analysis was validated using root mean square error and temperature error, obtained from temperature comparison between the numerical simulation results and the TRT data. The required total borehole length was achieved when the performance of the GSHP system attained the target performance for heating, after 30 years of operation. The GSHP system, designed by considering the partial groundwater flow, can reduce 30–40% of the total borehole length and 15–20% of the LCC, compared with the system designed based on conventional TRT analysis.