Experimental and numerical analysis of wet channels for evaporative cooling systems manufactured with polymeric film materials

Evaporative cooling systems have emerged as a sustainable alternative to conventional air-cooling methods, offering reduced energy consumption and environmental impact. This study evaluated the performance of four evaporative cooling channels manufactured using innovative polymeric films with varying porosities and compositions. Material characterization, including microstructure, surface roughness, and water absorption capacities, was systematically performed to identify critical properties affecting evaporative efficiency. Experimental analyses under controlled inlet air conditions identified the channel made of non-woven polypropylene produced by the spunlace technique as exhibiting the highest wet bulb effectiveness (80.6 %). Subsequently, a numerical model based on the effectiveness–number of transfer units (ε-NTU) method was developed, validated against experimental results, and utilized to optimize channel geometry and operational conditions. The numerical model indicated that increasing channel length significantly enhances cooling performance up to a saturation point at a channel length-to-free passage area of 1229 m−1, beyond which further improvements are marginal. These findings provide valuable guidelines for the design and optimization of polymer-based evaporative cooling systems, aiming to balance material properties, geometric factors, and operating conditions for maximum cooling efficiency and sustainability.