Exergy analysis of evaporative cooling to select the optimum system in diverse climates

In this paper, an exergy analysis is applied to indicate the exergy efficiency and irreversibility of common models of evaporative cooling. Exergy analysis of conditioned air are based on the results of experimental investigations on the direct, indirect, and two-stage indirect/direct evaporative cooling for six cities in Iran, each having various weather conditions. For this purpose, exergy balances of three cooling methods are derived. The results obtained reveal that for a comprehensive efficiency analysis, both the first and second law of thermodynamics should be considered. Furthermore, the direct evaporative coolers work best in temperate and dry climate with estimated exergy efficiency of 20%. The indirect evaporative coolers are more efficient in hot and dry climate with approximate exergy efficiency of 55%. The indirect/direct evaporative coolers are better choice for hot and semi-humid climate with exergy efficiency of about 62%. ► Experimental simulations of DEC, IEC, and IDEC were carried out for all ranges of climatic conditions in Iran. ► The exergy efficiency and irreversibility are studied on different types of evaporative cooling in five different climates. ► Like the first law of thermodynamics, the second law of thermodynamics shows IDEC are more efficient than both DEC and IEC. ► Minimum amount of irreversibility belongs to indirect evaporative coolers.