A STUDY ON THE EFFECT OF NON-UNIFORM LIGHTING ENVIRONMENT TO OCCUPANTS IN A WIDE OPEN-PLAN WORKPLACE

Partial lighting is regularly one of the energy-saving methods in open-plan office in Japan. However, this method sometimes produces uncomfortable visual environment with excessive non-uniformity. It is necessary to identify the permissible range of non-uniformity of lighting environment that also meets our demand for energy savings. This study was conducted to identify the effect of non-uniform lighting in a real open-plan workplace. The experiments lasted approximately three months with eight lighting conditions. The occupants evaluated each lighting condition every weekend. As a result, it was suggested that coefficient of variation of the one-half power of the ceiling luminance has correlation with the annoying level of non-uniformity.