Smart double glazing integrated polymer dispersed liquid crystal for enhancing building's thermal performance in hot-arid climate

Abstract

Polymer-dispersed liquid crystal glazing is an electrically activated smart switchable glazing that requires an AC power supply to become transparent and remains opaque without power. This dynamic feature, with multiple transparency states, is suitable for building in hot and arid climates. It can effectively reject unwanted solar energy, allowing visible light while contributing to building energy efficiency by reducing the carbon footprint. In this work, the PDLC glazing system was included with a low-e coated glass and this coupled system was investigated with two control approaches for residential buildings in hot arid climates. The first control is a standard On-Off operation based on the tenant preferences, while the second is able to set glazing transparencies according to the solar radiation intensity, in order to minimize the penetration of direct solar radiation and to provide daylighting and indoor privacy protection. The system is reversed to examine the proper positions and layer order in the glazing system. The proposed system demonstrates remarkable enhancements in indoor thermal performance, surpassing clear glass by 21 % in the south orientation and 25.5 % in the west orientation. Furthermore, when the PDLC is oriented towards the outdoor environment, the system achieves an impressive 53.9 % improvement in heat gain control compared to clear glass. Additionally, the system not only enables dynamic control over direct solar radiation but also offers efficient daylighting and indoor privacy protection.