Experimental Evaluation of Thermal and Lighting Performance Using Double Dynamic Insulated Glazing

Abstract

Designing windows in hot climates that allow occupants to easily control their preferences in a smart home is of considerable importance. This paper aims to contribute to this topic by examining the potential of a smart window system that has double dynamic insulated glazing (DDIG) in preventing heat gain and maximising daylight indoors, considering smart privacy protection during both the day and the night. A small-scale model was developed to examine the proposed window system. Test cell temperature, glass surface temperature and indoor illumination lux were investigated. The results showed that the DDIG had high solar heat control inside the test cell, with a significant reduction of 2.5 °C compared with the common glazing of translucent glass used in Najran City, Saudi Arabia. At high solar irradiation intensities, no significant differences in controlling the heat gain to the test cell were found between coloured DDIG (DDIG-colo) and transparent DDIG (DDIG-trans). A graded reduction between DDIG-trans and DDIG-colo was found with decreasing solar intensity, which was found to be 15%, 10% and 8.7% at irradiation intensities of 200, 400 and 600 W/m2, respectively. The DDIG transparencies maintained the illumination lux with higher reduction under low solar irradiation. The DDIG also provided privacy protection and granted user preferences for outdoor connections.

Keywords

• smart window
• PDLC glazing
• solar radiation
• thermal performance
• illumination
• dynamic transparencies