Thermal and cost assessment of various polymer-dispersed liquid crystal film smart windows for energy efficient buildings

Abstract

Buildings consume a considerable amount of energy for air conditioning and artificial daylighting. Buildings use glass as the main enclosing material to provide natural daylighting and for aesthetic reasons, but solar heat gain/loss through the clear glass into the buildings is enormous. This paper aims to explore the solar optical properties and air-conditioning cost-saving potential of various smart PDLC film glasses. This paper presents the solar optical properties of four different smart PDLC film glasses (white, blue, pink, and yellow) with and without applied voltage conditions. A numerical model was developed to compute solar heat gain through smart PDLCs in voltage ON/OFF states. And cost analysis was carried out to estimate the annual air-conditioning cost savings. All the smart PDLC film glasses in voltage ON/OFF conditions had shown a substantial reduction in heat gained/lost compared to generic clear glass in buildings of three climatic conditions. The reduced heat gained/lost in the smart PDLC film glasses accounted for the net annual cost savings (heating cost + cooling cost). The white smart PDLC film glass WSPG (V) was observed to be the most energy-efficient smart glass with the highest annual air-conditioning cost savings ($ 101.76 in the SE of hot and dry climate), lowest payback periods (12.71 yrs in SE of hot and dry climate), and adequate daylight factors as compared to the other studied smart glasses in eight orientations of three climatic conditions. The results help to design and select suitable glazing for sustainable and energy-efficient solar passive buildings.