Near-infrared blocking window based on ATO-CWO/PVB nano-lamination

Abstract

With the green developments of buildings, the next-generation windows are supposed to have excellent energy-saving behaviors, including thermal insulation and solar control. In this study, a novel ATO-CWO/PVB nano-laminated glazing with excellent NIR blocking ability was designed and fabricated. Such glazing has a good luminous transmittance at 63.2% while can block 94.5% of the whole NIR with wavelength between 780 and 2500 nm, which is far better than its counterparts such as ATO-based glazing, CWO-based glazing, metallic nanoparticle-based and metallic oxide nanoparticle-based glazing. In addition, the lamination design of ATO-CWO/PVB nanocomposite ensured its isolation from the air and can thus maintain long-term durability. Traditional CWO products would lose the NIR shielding ability within 3 months under the natural solar radiation, while the ATO-CWO/PVB nano-laminated glazing was demonstrated to maintain fairly stable optical properties in 5 months. Based on the nano-laminated glazing proposed in this study, a double-layered energy-efficient window was fabricated further, and outdoor experimental test was carried out to investigate its light/heat regulation performance, in comparison to the existing windows, including normal laminated glazing window and normal window. Results demonstrated that the newly developed energy-efficient window can achieve an indoor temperature decrease of 7.82 °C/6.64 °C, compared with double-layered clear window and double-layered normal laminated window, whereas it decreases the luminous level by about 37%/41% respectively. In order to further verify its energy-saving performance in hot regions, energy consumption simulation was conducted in Energy Plus software. Results showed the double-layered energy-efficient window can reduce the annual electricity consumption by 14%–18% in Hong Kong, compared with other tested windows.