ANALYSIS OF PRESENT SITUATIONS AND DECISION FACTORS FOR INSTALLATION OF GROUND SOURCE HEAT PUMP SYSTEMS IN LOCAL GOVERMENTS OF JAPAN BY INQUIRY SURVEYING

Abstract

 This study demonstrated an inquiry survey for local governments of populations over 50 thousand in Japan and all governments in Hokkaido Island to analyze present situations and decision factors for the installation of ground source heat pump systems in public buildings. The number of answered governments reached at 443 for the former governments and 117 for the latter, respectively. About 90 % of the answered governments know “what a ground source heat pump system is” more and less, but only about 10 % have installed the systems. The former and latter governments commonly responded high initial costs as the primary issue for the installation, as suggested by previous researches. As secondary issues, the former requested to standardize how to design the system, and the latter governments to evaluate the contribution to the environments. Linear discriminate analysis indicated that the decision factors in the former governments were the degree-day for heating, the number of affiliated companies in the geo-heat promotion association, and the population, and in the latter governments were the population, its increase during five years, and environmental activity in the national policy. Finally, this study derived approximated power functions of capital costs for borehole heat exchangers and heat pumps, respectively, in the least square based on the inquiry survey data, as references for practical design and planning of ground source heat pump systems in public buildings.