Experimental performance analysis of non-porous indirect evaporative coolers under intermittent water spraying conditions

Faced with extreme global heat, the demand for efficient air conditioning is critical, especially using environmentally friendly technologies such as natural refrigerants. It makes the exploration of traditional solutions, such as evaporative cooling (EC), crucial. Our study investigates the performance of dewpoint indirect evaporative cooling (DIEC) systems, focusing on non-porous heat exchangers with intermittent water supply to enhance cooling efficiency and reduce energy consumption. In this experimental study, we evaluated key performance indicators of the DIEC system, including dew point and wet bulb effectiveness, cooling power, and coefficient of performance (COP), under various water spraying intervals (30 s, 60 s, 90 s of spraying and constant spraying) and different inlet air velocities (1.6 m/s, 2.0 m/s and 2.5 m/s). The results indicate that an intermittent water supply significantly reduces electrical energy consumption without compromising system performance . Notably, the highest COP, ranging from 50 to 107, was observed during the shortest 30-s spraying intervals, compared to a COP of approximately 20 during constant spraying. These findings highlight the effectiveness of optimizing water management strategies in DIEC systems. The adoption of intermittent water supply in DIEC devices with non-porous heat exchangers offers a viable and sustainable path to improving air conditioning efficiency, making it a promising solution for addressing the growing demand for environmentally friendly cooling technologies. • Non-porous DIEC was experimentally tested with intermittent water supply. • Different spraying times and different inlet air velocities were evaluated. • Intermittent water supply boosts COP by up to 5 times. • A 30 s spray time enhances cooling capacity up to 85 % compared to constant spraying. • Proposed modifications can be applied without altering the DIEC device structure.