The Effect of an Evaporative Cooler on the Thermal Performance of Passive Ventilation System Coupled with EAHE: An Experimental Investigation

An experimental study of a two-storey structure with a passive ventilation system is conducted in August, with the severe summer environment of Kut, Iraq. The experimental model consists of a solar chimney combined with a hybrid cooling system comprised of an Earth-air heat exchanger and an evaporative cooler. Each storey has a size of 1 m3, while the dimensions of the vertical solar chimney were 3m height, 1m width and 0.3m depth. The dimensions of the evaporative cooler were (0.3 * 0.3 * 0.6) m3; it has a two-nozzle water spray system and a low-power fan with a speed of 0.8 m/s. The Earth-air heat exchanger was 17 m long, 10.2 cm in diameter and 3 m deep under each floor. Two instances were investigated with and without EV for two separate daytimes (2-8-2021 and (3-8-2021). The findings revealed that EV increases the relative humidity inside each storey and enhances the thermal comfort rate. Based on recorded data, the relative humidity rate ranged from 35% to 42%, contrasted to the exterior relative humidity, which did not surpass 13%. In addition, the EV assisted in lowering the indoor temperature of each storey by 4 °C. Finally, due to the high solar radiation at the Kut city location in Iraq, the passive ventilation rates for the solar chimney were satisfactory for both storeys.