Effective indirect evaporative cooling using superhydrophobic nano-architectured porous ceramics

Indirect evaporative coolers (IECs) offer a unique opportunity to meet the rapidly growing global cooling demand while reducing the environmental impact of traditional vapor compression systems. Despite their promise, widespread adoption of IECs has been hindered by challenges in material selection, system scalability, water use, and production efficiency. Here, we present the cSNAP (Ceramic Superhydrophobic Nano-Architecture Process) IEC system, designed to address these limitations using readily available materials and streamlined manufacturing techniques. The cSNAP IEC system comprises a robust ceramic heat exchange element (HXE) manufactured via standard extrusion processes, a novel spatially selective superhydrophobic metal oxide vapor barrier, and integrated compact manifold units with essential components for operation. The innovative design leverages the ceramic HXE's dual functionality: a thermally conductive water vapor transmission barrier for sensible heat transfer to the product air channels and a porous, water-absorbent medium for latent cooling of the working air channels. By discretizing these properties into isolated flow channels, the cSNAP system enables high-efficiency, regenerative heat exchange, achieving near-wet-bulb cooling without the use of high global warming potential refrigerants. The performance of the cSNAP IEC was experimentally evaluated and piloted in a two-week field study. Results demonstrate significant energy and water efficiency, with a high cooling capacity of 1.0 to 1.4 kWh, a coefficient of performance >8, and Water Use Efficiency >90 %, all while delivering 100 % outdoor air. These findings highlight the potential for advanced design engineering of ceramic materials to overcome historical barriers to IEC adoption, thereby expanding their applicability to a broader range of buildings and climates.