Effect of an evaporative cooler on the thermal performance of passive ventilation system coupled with earth air heat exchanger: an experimental investigation

Abstract EN

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, Im 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 Evaporative cooler(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.