Possible Utilization of Ground-Coupled Heat-Pump System in Tropical Countries

Abstract

Possibility of ground-coupled (geothermal) heat-pump application in tropical Asia is studied based on groundwater temperature data. Although generally geothermal heat-pump system may not have thermal merit for space cooling in tropics, there may be some places in tropical regions where underground can be used as cold heat source. In order to confirm this possibility, groundwater temperature surveys were widely conducted in the Chao-Phraya plain, Thailand and in the Red River plain in Viet Nam to compare with climatic data. As a result, regional variation of subsurface temperature at depths from 20 to 50 m of 3.4K was observed in the whole Chao-Phraya plain and 2.0 K in the Red river plain. In some cities, subsurface temperature lower than surface one (monthly mean maximum) for 5K or more over four months was identified. Thus underground may be used as cold heat-source even in parts of tropical regions. Detailed underground temperature survey is essential for its promotion.