Daylight Glare Probability Measurements And Correlation With Indoor Illuminances In A Full-Scale Office With Dynamic Shading Controls
glare, visual comfort, offices, DGP
Daylight glare evaluation has been the recent focus of research on visual comfort since newer office buildings have large glass facades offering daylight provision and outdoor views. Available glare indices are related to source luminance size and location, view direction and background luminance. The Daylight Glare Probability index that considers vertical illuminance at the eye level, has been identified as one of the reliable metrics, since it was based on experiments with real human subjects. In this study, extensive experiments were conducted in a full-scale private office environment with dynamic shading controls, to measure interior luminance and illuminance conditions under variable sky conditions and shading control strategies. A high dynamic range camera with a fish eye lens was used to capture the luminance in the field of view, while horizontal and vertical illuminance was measured at different positions. The images were processed for calculating DGP values based on the “evalglare” method. The results are used to evaluate the efficiency of control strategies in terms of glare probability, while correlations between indoor illuminances, sky conditions and DGP may lead to simplified criteria and guidelines for controlling daylight glare in office spaces. Finally, the experimental results can be used for a daylight model validation for spaces with dynamic facades.
Daylight Glare Probability measurements and correlation with indoor illuminance in a full-scale office with dynamic shading controls