Experimental evaluation for daylight‐linked gradation lighting control using image‐based motion sensors

Abstract

AbstractIn this study, we propose a daylight‐linked gradation lighting control, which adjusts the dimming level of a light above an occupant according to daylight and also gradually lowers the dimming level of surrounding lights based on the distance from the occupants by using image‐based motion sensors. We evaluated it in terms of both energy savings and visual comfort of the occupants in comparison experiments. Compared with the individual occupancy control (IC), the actual and simulated median energy savings of daylight‐linked gradation control (DGC) were 27.1 and 28.9%, respectively, per day. The results of a questionnaire consisting of seven questions and using a semantic differential method for scoring visual comfort showed that the DGC tended to improve visual comfort compared with the IC. Further experiments, however, are needed as only four of nine occupants responded to the questions. In addition, we found that the DGC creates a smoother contrast in the office than the IC, which may produce conspicuous changes in illumination intensity. Finally, we analyzed the advantages and disadvantages of the DGC on the basis of our experimental results. © 2020 Institute of Electrical Engineers of Japan. Published by John Wiley & Sons, Inc.