- March 28, 2020
An experimental investigation of the performance of a direct-indirect evaporative cooling fresh air handling unit with different modes of operation is presented. Linear regression analysis is used to fit the experimental results, and the correlation coefficient is evaluated. It is found that the highest temperature reduction of 18.8°C is achieved across the heat exchanger for the tested unit when the water shower mode is implemented at an ambient dry-bulb temperature of 44°C in conditions of relative humidity less than 20%. In the water shower and the combined mist injection and water shower modes of operation, the temperature reduction across the heat exchanger generally reduces, with increasing relative humidity. Furthermore, the results showed that water consumption increased with increasing ambient dry-bulb temperature and decreased with increasing ambient relative humidity. Finally, the lowest energy consumption of 1.64 kWh occurred with the water shower mode operated at peak dry-bulb temperature design condition. The energy consumptions for the mist injection mode of operation were 1.89 kWh and 2.15 kWh for the peak dry-bulb temperature and peak wet-bulb temperature design conditions, respectively. At these design conditions, the energy consumptions of the combined mist injection and water shower mode of operation are 2.7 kWh and 2.83 kWh, respectively. © 2020 International Information and Engineering Technology Association. All rights reserved.