EFFECT OF DIFFERENT DESIGN PARAMETERS ON THE VISUAL AND NON-VISUAL ASSESSMENT CRITERIA IN OFFICE SPACES

Abstract

Light entering the human eye does not only enable the performance of visual tasks, but also influences the health and well-being of humans via non-visual effects. A substantial amount of people in the Western society spends the majority of their work time indoors. Well-designed lighting positively impacts the visual comfort and well-being of people working in offices. Current standards for office lighting design are solely based on enabling the visual tasks via recommendations for photometric quantities such as the maintained illuminance on the task and surrounding areas and/or the glare limitation. The luminous radiation that contributes to the health related non-visual effects is not addressed in these recommendations at all. It is therefore essential to include the impact of effective luminous radiation in the lighting design process. This paper discusses the necessary distinction between photometric quantities on one side and effective luminous radiation on the other side. It investigates the effect of design parameters such as 'window size', 'exterior ground plane color and luminous reflectance' on the visual and non-visual effects for different view directions. Simulations have been conducted for the IEA Task 27 reference office using the light software tool Radiance The findings show reverse influence of the exterior ground plane color and luminous reflectance on the visual and non-visual effects of light. While the exterior ground plane luminous reflectance plays an important role on the visual evaluations, its color is the most influential design parameter for the non-visual evaluations. For the optimal health related non-visual effects of light, findings suggest using bluish exterior ground plane and placing the work plane facing the window.