Dynamic daylight glare evaluation

In non-residential buildings, comfort and energy demand for heating, cooling and lighting are significantly influenced by the façade. Up to now, only non-weighted luminance-based methods for calculating and evaluating annual daylight glare exist (Lee et al., 2005; Mardaljevic and Lomas., 1998). Within this paper, different methods based on the daylight glare probability DGP (Wienold and Christoffersen, 2006) for a dynamic calculation of glare are discussed and evaluated: Timestep by timestep calculation - RADIANCE reference method. Simplified daylight glare probability DGPs - DGP only based on vertical eye illuminance. Results of this method are similar to average luminance based evaluations. Enhanced simplified DGP calculation - DGP based on vertical eye illuminance and simplified images. The enhanced simplified DGP method is validated against two hour-by-hour full year calculations, using a fabric and a Venetian blinds shading system. For the yearly evaluation of dyna mic glare results, a histogram analysis and a glare rating classification is proposed.