A novel approach for optimized design of low-E windows and visual comfort for residential spaces

Double low-E glasses are effective and well-established choices for residential buildings in temperate climatic regions of Sydney, Australia, and Tehran, Iran. The current study's measurements and field experiments have shown that using a double low-E windowpane can improve window total transmitted radiation energy (TSRE) and daylight glare factor. Nevertheless, spatial daylight autonomy (sDA) and daylight illuminance are the shortcomings of using double-low-E glasses. These implications demonstrated that using double low-E glazing is a double-edged sword. Despite its efficiency in improving energy consumption, it cannot satisfy daylight comfort requirements. Therefore, this research intends to find the most suitable solution to exploit double-low-E glasses' benefits and avoid their drawbacks. Subsequently, the genetic algorithm has been used to find the optimum window size through a multi-objective simulation by Climate Studio. The findings suggest that the optimum WWR of 10.35%–10.99% in Tehran brings the daylight comfort metrics above the threshold while the energy consumption metrics are kept at a minimum. Similarly, for Sydney, these measures are 20%–24% room length for the horizontal dimension of a window and 33%–40% room height for the vertical penetration dimension. In this way, using a double low-E window pane is justifiable for both examined regions.