Paper Title
Application of a Groundwater Cooling System as Thermal Barrier to Establish a Comfortable Environment

Abstract
Taiwan is limited in space with dense population, and is located in sub-tropical region with high ambient temperature and humidity. The development of buildings must consider issues on the climatic condition, population, and land usage. In recent years, changes of social structure and nature of work cause people to stay indoors longer. Thus, pursuing a comfortable indoor working and living environment is become an important research topic. Thermal barrier technologies have become an important energy-saving for space heating and cooling of residential and commercial buildings in many countries. Building energy efficiency can be improved by implementing either active or passive energy efficient strategies. Improvements to heating, ventilation and air conditioning systems etc. can be categorized as active strategies, whereas, improvements to building envelope elements can be classified under passive strategies. Using groundwater cooling system as thermal barrier is one of the effective passive strategies. Groundwater cooling system is composed of galvanized iron pipes located inside of walls. Fluid flows inside the pipes and then supply constant cooling temperature. In the study, system using of groundwater as renewable energy source for pipes cooling. The groundwater at depth of more than 5 meters below the surface has constant temperature year round. Lower temperature groundwater would cool the pipes of system by heat exchange process to achieve the cooling effect of wall. In this research, cooling wall system was evaluated to reduce the thermal transfer from sunlight into the buildings, thus reducing the electricity consumption needs for air conditioning of the buildings. Keywords: Groundwater cooling system、Thermal barrier、passive strategies.