2019 Volume 15 Issue 3 Pages 269-281
The aim of this study is to evaluate the environmental performance of a ground source heat pump （GSHP） system in a tropical region. We conducted a life cycle inventory （LCI） analysis wherein an optimally-designed GSHP system is installed in a commercial building in Bangkok, Thailand. An air source heat pump （ASHP） system was chosen as a comparison system. LC-CO2, NOx and SO2 emissions were estimated for the LCI analysis. Based on the condition of the circulated water temperature, LC-CO2, NOx and SO2 emissions of the GSHP system were reduced by 28.8%, 25.3% and 26.6%, respectively in the optimally-designed GSHP system compared with the ASHP system. Next, a sensitivity analysis was conducted by changing the length of the geothermal heat exchanger and the scale of the building within the design standards of the heat exchange rate commonly used in Japan. The results indicated that the life-cycle of the environmental load of the GSHP system decreases with increasing length of geothermal heat exchanger, and within the range of the sensitivity analysis, is lower than that of the ASHP system. However, a large geothermal heat exchanger is required for comparison at the scale of the building. Furthermore, the sustainability of the GSHP system with a long-term rise in underground temperature is not determined. Further research is required to evaluate and determine the sustainability of GSHP system as well as conducting investigations from an economic perspective.
