Performance insights into cooling pad materials for efficient evaporative cooling in hot and humid climates

Hot and humid climates pose a significant challenge for energy-efficient space cooling, as conventional vapor-compression systems are expensive and carbon intensive. Direct evaporative coolers (DECs) offer a low-energy alternative, but their performance depends critically on the choice of cooling pad material. This study experimentally evaluates various locally available natural pads such as luffa, date palm fiber, jute fiber, sackcloth, wood chips, and sugarcane bagasse alongside the commercial CELdek pad in a DEC system. Results show that CELdek delivers the highest cooling potential of 401.01 W with a saturation efficiency of 43% and the greatest exergy about 32.1 W, establishing it as the benchmark material. Among natural specimens, jute and luffa-based hybrids performed competitively, with jute-aspen reaching an exergy of 28.08 W. Sugarcane bagasse, while the least effective in exergy of 18.9 W, offered lower CO₂ emissions and the shortest payback period to 2.34 years. The system’s low power demand (115 W) and reliance on local resources align with UN Sustainable Development Goals (SDGs) 7, 11, 12, and 13. Overall, the findings highlight CELdek as the most effective cooling pad, while also demonstrating that certain hybrid natural materials provide viable, sustainable, and cost-efficient alternatives for DEC applications in resource-constrained settings. • CELdek pad gives highest cooling potential (401 W) and saturation efficiency (43%). • CELdek pad shows the greatest exergy (32.1 W) and sustainability index (1.47). • Jute+aspen hybrid pad offers good exergy (28.08 W) and sustainability (1.39). • Sugarcane bagasse has the lowest exergy (18.9 W) among the single materials tested. • The DEC setup shows low CO 2 emissions and a payback period of around 2.34 years.