EVALUATION OF VISUAL ENVIRONMENT IN AN OFFICE WITH NOVEL LED LIGHT FIXTURES (PP20, 604-610)

LED lighting has high directionality, a small amount of light is emitted to the ceilings or walls. In order to avoid dark ceiling and wall, a point-source-type LED light fixture emitting direct and indirect light has been developed. It is expected that an office space with this LED lighting system increases workers? alertness and cognitive performance. On the other hand, there are concerns that this system may cause discomfort glare. In this study, we evaluated the visual environment in an office using the direct-indirect LED lighting system. Luminance distribution, subjective impression, workers? alertness, brightness and discomfort glare are measured and evaluated by field and 1/10 scale model. The subjects judged that the visual field and desk surface illuminated by the narrow-beam point-source LED lighting system was brighter than that illuminated by the conventional light fixtures.