Spatial evaluation of potential saturation and contrast effects of discomfort glare in an open-plan office

This paper analyzes the relative distribution of annual saturation and contrast effects of discomfort glare in a deep open-plan office. A previous comparative study has shown that while hybrid glare metrics were found to predict glare well in most scenarios occurring in the investigated datasets, contrast-driven glare metrics predict discomfort glare better than saturation-driven metrics in daylit conditions when vertical illuminance is lower than 3000 lux; and saturation-driven glare metrics outperform the contrast-driven metrics when vertical illuminance is above 3000 lux. The focus of this paper is to determine the potential effects of contrast-driven and saturation-driven glare across the floor plan, simulating annual hourly vertical illuminance (Ev) and contrast (log_gc) were simulated in 8 view directions with a grid spacing of 0.75m, at a typical eye level of 1.2m, for daylight hours in the context of Geneva, Switzerland. To identify viewpoints where saturation and contrast effects of glare dominate, a synthetic and versatile spatial visualization approach was established. A new simulation method allowed us to calculate detailed annual saturation and contrast metrics in a reasonable timeframe. Results show that high contrast lighting conditions occur far more frequently than high saturation conditions except for a narrow area near the façade.