Experimental study of an innovative counter-flow dew-point indirect evaporative cooler with polymer composite membrane

Abstract This study experimentally evaluates an innovative double counter-flow dew-point evaporative cooler with efficient wet-channel materials for residential building cooling. Tested under varying conditions in a double enthalpy-difference laboratory, the system achieves 118% wet-bulb effectiveness and 83% dew-point effectiveness at a 1:1 secondary/primary air ratio (dry-bulb temperature of 38°C and wet-bulb temperature of 23°C), delivering 3.31 kW cooling capacity. Compared to other existing systems, wet-bulb and dew-point effectiveness improve by 11.74% and 10.67%, respectively. The coefficient of performance (i.e. COP) reaches 10–13.2 in dry regions and 8.4 in humid climates, demonstrating superior energy efficiency for sustainable air conditioning. The new dew-point indirect evaporative cooler adopts a new structural design, wet material, and intermittent water supply scheme, which significantly improves the wet-bulb effectiveness, dew-point effectiveness, and COP compared with existing air coolers of the same type, and provides new ideas for material and structural innovations in subsequent research.