Experimental Investigation of Direct Evaporative Cooler with Sisal, Hemp, and Abaca Cooling Pad Material

Abstract

Evaporative cooling is environmentally friendly and a more efficient air cooling method. The efficiency of evaporative cooling systems increases with an increase in temperature and decrease in humidity. Therefore in hot and dry climates, evaporative cooling can save a large amount of energy used for conventional air-conditioning systems. Direct Evaporative Cooler (DEC) uses a wetted pad with large air-water contact surface area through which air is passed at a uniform rate to make it saturated. However, this process is accompanied by an increase in humidity which is sometimes not desirable. Thus, it is seen that a variety of materials that can be used as cooling media in direct evaporative cooler is very large. Hence there is a need to analyze the performance of alternative materials in terms of saturation efficiency and cooling capacity. Further, the performance of a cooler using hemp and abaca as cooling media has not been analyzed. Hence, the attempt is made to fabricate and analyze the performance of such cooler in the present work. The efficiency of evaporative cooling systems increases with an increase in temperature and decrease in humidity. In the developed direct evaporative cooler, 15–20% effectiveness is more in case of hemp as cooling pad material as compared to the abaca and Sisal cooling pad material. Enhancement in effectiveness is 10–15% more in case water flow rate at 220 LPH in all cooling pad material as compared to 180 LPH and 200 LPH. Average outlet dry bulb temperature was varying between 240 and 280 °C. Cooling capacity can be improved by increasing the water flow rate through the cooling pad and the dry bulb temperature of incoming air can be reduced below its wet-bulb temperature.