Experimental study of a counter flow regenerative evaporative cooler with finned channels

A regenerative evaporative cooler has been fabricated and tested for the performance evaluation. The regenerative evaporative cooler is a kind of the indirect evaporative cooler comprised of multiple pairs of dry and wet channels. The air flowing through the dry channels is cooled without any change in the humidity and at the outlet of the dry channel a part of air is redirected to the wet channel where the evaporative cooling takes place. The regenerative evaporative cooler fabricated in this study consists of the multiple pairs of finned channels in counter flow arrangement. The fins and heat transfer plates were made of aluminum and brazed for good thermal connection. Thin porous layer coating was applied to the internal surface of the wet channel to improve surface wettability. The regenerative evaporative cooler was placed in a climate chamber and tested at various operation condition. The cooling performance is found greatly influenced by the evaporative water flow rate. To improve the cooling performance, the evaporative water flow rate needs to be minimized as far as the even distribution of the evaporative water is secured. At the inlet condition of 32 °C and 50% RH, the outlet temperature was measured at 22 °C which is well below the inlet wet-bulb temperature of 23.7 °C.