13 December 2005
In Europe and North America, ground source heat pump (GSHP) systems have provided heat mainly for buildings or, in the early stages, for snow melting. This has not occured in Japan, due to high excavation costs. If such systems are to be used in Japanese cities, three problem areas need to be considered: 1) reduction of the initial construction costs, 2) improvement of the performance of water source heat pumps and 3) development of simulation methods for heat transfer in the ground. Since 2003, the authors have working on these areas, with support from the New Energy and Industrial Technology Development Organization of Japan (NEDO). This article describes the results of twoo years’ work.