PERFORMANCE ANALYSIS OF EARTH TUBE HEAT EXCHANGER

This study performs an analysis of Earth Tube Heat Exchangers used to improve the efficiency of heating, ventilation, and air conditioning (HVAC) systems. ETHE can be used in either a heating or cooling mode by taking advantage of a “near constant” ground temperature. The “near constant” ground temperature can be used as either a heat sink to remove heat to cool a building, or as a heat source to heat a building. The outlet temperature of air was determined by using effectiveness of ETHE (ε) which is a function of number of transfer units (NTU). The effectiveness of earth–air heat exchanger is determined by the dimensionless group NTU. The all analysis based on cooling test because of in winter session ETHE was not prepared for input parameter. ETHE is made of 19.22 m long PVC pipe of 10.6 cm nominal diameter and 3 mm wall thickness. ETHE is buried 2 m deep below surface. Ambient air is pumped through it by a 125w blower. The analysis based on the values of normal speed of air flow (1.8, 3.5, 5 m/s) and static mean temperature of air in three consecutive summer months March,April,May were (32.2, 37.8, 40.3 0C) respectively at inlet obtained from experimental set‐up installed at Bhopal (Central India). At higher outlet velocity and maximum temperature difference, the system is most efficient to be used