2020 Volume 99 Issue 6 Pages 57-66
The purpose of this study is to find out natural and social conditions to effectively reduce CO2 emissions by installing ground source heat pump systems (GSHPs). This study estimates life cycle CO2 reduction potential of GSHPs for air-conditioning in office buildings under various natural and social conditions. Six hundred and forty possible patterns are generated by combining the following four conditions: climate, air-conditioning systems used at present, scales of office buildings and CO2 emission factors of grid electricity used. Based on the CO2 reduction potential of each pattern, this study analyzes patterns under which the GSHPs installation can effectively reduce CO2 emission. The analysis finds that the installation of GSHPs can reduce CO2 emission for about 40% (250 patterns) of all the 640 patterns. In particular, the GSHPs installation allows for higher CO2 reduction in patterns that meet following conditions: (1) when GSHPs substitute absorption chiller-heaters in the area where the CO2 emission factors of grid electricity are low and (2) when GSHPs substitute air source heat pumps in cold areas. In addition, sensitivity analysis is conducted considering a decrease in CO2 emission factors of grid electricity and the efficiency improvement of GSHPs in the future.