Self-cleaning and de-pollution efficacies of photocatalytic architectural membranes

Photocatalytic self-cleaning “cool” roofs and walls can maintain high albedos, saving building cooling energy, reducing peak power demand, mitigating the urban heat island effect. Other environmental benefits result from their de-polluting properties. Specimens two different photocatalytic architectural membranes a non-photocatalytic control were exposed alongside vertically, facing west, for years at three California sites, retrieved quarterly testing. materials showed excellent performance, retaining albedos of 0.74 – 0.75. By contrast, material exhibited an albedo loss up to 0.10, with appreciable soiling observed by scanning electron microscopy. De-pollution capacity was assessed quantifying NO removal NOx deposition rates 60 °C. Efficacy varied exposure location, weather conditions, nature material. Seasonal effects observed, partial inhibition during dry season reactivation rainy season.