2025-06-052025-06-052025-03-27Almodóvar Melendo, J.M. y La Roche, P. (2025). Thermal evaluation of a water-to-air heat exchanger combined with different roof configurations for passive cooling. Buildings, 15 (7), 1098. https://doi.org/10.3390/buildings15071098.2075-5309https://hdl.handle.net/11441/173965Traditional conservation strategies often prioritize minimizing water use; nevertheless, water can also enhance thermal comfort by incorporating a water-to-air heat exchanger (WAHE) alongside non-direct evaporative and radiant cooling techniques. A WAHE can be installed in features such as ponds, water tanks, or rainwater cisterns. This article assesses the cooling potential of two prototypes of roof ponds and a green roof connected to a WAHE, and the results are compared to a baseline unit featuring a roof that meets California’s energy code standards. Several testing units, measuring 1.35 × 1.35 × 1.35 m, with identical heat characteristics, excluding the roof, were constructed and tested. In the first system, the heat that the green roof could not absorb was transferred to a water reservoir and then dissipated to the outside. The first roof pond prototype features a 0.35 m deep water pond topped with a 0.03 m thick insulating panel and a spray system. The second roof pond variant has an aluminum sheet with a 0.10 m air gap above a 0.25 m deep water pond. The results suggest that combining a WAHE with different roof configurations offers promising benefits while keeping water consumption limited. Notably, when the WAHE is operating, the green roof increase its performance by 47%, the insulated roof pond by 22%, and the roof pond with an aluminum sheet by 13%.application/pdf20 p.engAttribution 4.0 Internationalhttp://creativecommons.org/licenses/by/4.0/Energy conservationPhysical testing mockupsRoof pondGreen roofWater-to-air heat exchangerPassive coolinginfo:eu-repo/semantics/articleinfo:eu-repo/semantics/openAccess10.3390/buildings15071098