Energy accumulation in the soil may be used with Earth-Air Tunnel Heat Exchanger (EATHE), which has single tube or groups of tube buried in the ground (soil). In a country like India, there exist big gap in demand and supply of electricity and compels to look for alternative. A thermal model was developed to analyze the thermal energy accumulated in soil/ground for the purpose of room heating and cooling of buildings. In this paper Thermal performance of Earth Air Tunnel Heat Exchanger (EATHE) under transient operating conditions in summer season has been evaluated for predominantly hot and dry climate of Bikaner (India) using Computational Fluid Dynamics (CFD) modeling. Effect of time duration of continuous operation and thermal conductivity of soil on thermal performance of EATHE under transient conditions has been analyzed. EATHE CFD model consist 14.5 m long mild steel, inlet and outlet of PVC 3.5 m depth and 0.1 m diameter with 0.01 m wall thickness. For this analysis two types of soil sandy and sandy loam soil of Bikaner region has been considered. Cooling effect during summer by EATHE analysis has decrease temperature by 17.8°C for Sandy Soil and 13.8°C for Sandy Loam Soil was at air velocity 9 m/sec.Keywords: Thermal conductivity, CFD, Temperature, Velocity, Density, Earth Air Tunnel Heat Exchanger.
