Effectiveness enhancement and performance evaluation of indirect-direct evaporative cooling system for a wide variety of climates

Application of evaporative cooling systems for providing thermal comfort conditions is scrutinized. The thermal comfort criterion is mainly used for the optimum design of the air conditioning systems. ISO 7730 as thermal comfort standard is utilized to evaluate the capability and performance of above-mentioned systems for the variety of climates in Iran. A finite difference method is used to optimize the geometric and operating parameters of evaporative cooling systems. The influences of plate spacing, air flow velocity, and wettability factor of surface are investigated on the air properties and effectiveness of systems. Effectiveness of the evaporative cooling systems increases in the case of using a narrow channel width, reducing relative humidity of air entering into secondary channel, utilizing of substances with more wettability factor of surface, and surging in the ratio of air flow velocity in secondary channel to the primary one. Among nine proposed evaporative cooling systems, co-current direct evaporative cooler and f-type, i.e. cross flow indirect evaporative cooler have the highest efficiency with 73% and 40%, respectively. Thus, these systems because of providing cooling demand with high efficiency are combined to make indirect/direct evaporative cooling system, employed for selecting of appropriate evaporative cooling systems in variety of climates of Iran. By generalizing the results of this research, the proper evaporative cooling system can be determined for all climates around the world. (R) 2018 American Institute of Chemical Engineers Environ Prog, 38:e13032, 2019