100-YR PREDICTIONS OF PERFORMANCES IN A GROUND-SOURCE HEAT PUMP SYSTEM FOR AN OFFICE BUILDING UNDER DIFFERENT CLIMATE SCENARIOS

Abstract

 The purpose of this study is to evaluate the long-term efficiency of a ground-source heat pump system through a simulation for 100-yrs from 2001 to 2100 at an office building in cold Sapporo and warm Tokyo under three different scenarios of climate change. Hourly meteorological conditions were estimated from originally monthly data, and the calculation of thermal demands in a building followed. Underground temperatures were predicted considering thermal and water budgets on the surface. As a result, 20yrs-averaged seasonal performance factors were expected to be kept for both cooling and heating and by both vertical and horizontal heat exchangers. However, the performance will become lower in a specific case for heating in Tokyo because of constant electricity consumption for circulation pumps. The difference in the seasonal performance factors among the three scenarios was less than 0.1-0.2 in Sapporo. The value was about 0.7 for heating in Tokyo, indicating the uncertainty in the system efficiency under climate change.