Evaluation of an Earth-to-Air Heat Exchanger for the North-East of Iran with Semi-Arid Climate

The use of non-fossil energy resources is being promoted in Iran because of Iranian Subsidies Reforms. The effect of relevant parameters, including burial depth, pipe length, air velocity, and pipe material on the performance of an earth-to-air heat exchanger was investigated in the north-east of Iran. Based on 72 experimental trials, it was determined that all parameters had significant effect of system performance except pipe material. Moreover, the coefficient of performance of the system for cooling mode with 5.5 was higher than for heating with 3.5. More investigations are ongoing to optimize the related parameters for husbandry applications in the region.