Study on ground source heat pump using housing foundation pile

Abstract

A ground source heat pump (GSHP) is attracting attention as one of the energy saving technologies. GSHP that use direct expansion method uses an underground heat exchanger which is put a copper pipe directly in a borehole of 20-30 m. We have carried out an experiment using the underground heat exchanger which inserted the copper pipe in the steel pipe pile. This paper describes performance evaluation of the GSHP system with 15 steel pipe piles as heat exchanger. Coefficient of performance (COP) is used as evaluation method of the GSHP system. Experimental result shows that the average COP became 7.0 and the average cooling power was 3.15kW in cooling mode. On the other hand, the average COP became 5.5 and the average heating power was 2.48kW in heating mode. COP of this system was higher than that of the indirect GSHP system.