Experimental analysis of a direct expansion ground coupled heat exchange system for space cooling requirements

Abstract

Ground coupled heat exchanger system is the promising technology for space heating/cooling where winters (summers) are quite cold (hot) and there is substantial variation in temperatures during the day. Ground coupled heat exchanger system can be classified as earth-air-heat-exchanger and ground source heat pump system. Further ground source heat pump system can be categorized as regular and direct expansion ground coupled heat pump system. The performance of conventional air conditioner, based on vapor compression system can significantly be enhanced by coupling ground-coupled heat exchange system. In the present research, an attempt has been made to boost the performance of cooling system viz. coupling of buried copper condenser tube with the compressor of conventional air conditioner. The proposed system is one of the direct expansion ground coupled heat pump systems. The techno-economical performance of the proposed system has been experimented in three different modes. The power consumption compared to base mode (i.e. conventional air conditioner) reduces when horizontal and vertical direct expansion ground coupled heat pump systems are used. Economic analysis factors, such as simple payback period, discounted payback period, net present value and internal rate of return show that vertical configured buried copper tubes provide more economic feasibility than horizontal.