Journal of Korean Institute of Architectural Sustainable Environment and Building SystemsISSN:1976-6483(Print) 2586-0666(Online)한국건축친환경설비학회

The dimming control of the indoor lighting requires for detecting or predicting the work plane illuminance. However, it is difficult to install the illuminance sensor on the work plane due to objects and/or occupants in the room. In order to overcome this problem, the illuminance sensor is installed on the ceiling surface. In this case, the illuminance ratio of the work plane to the ceiling is an important factor in the dimming control. The illuminance ratio is affected by many factors such as the shape of the room, the type and brightness of the light, the reflectance of the wall and the floor, and the interior objects. The research analyzed the relationship between the illuminance ratio and the reflectance of the wall in a typical small office model space, which was built to evaluate the dimming control. To do this, simulation model was developed using Relux and was validated with the mock-up tests. Simulation results revealed that the average illuminance ratio (Y) according to the wall reflectance (X) was Y=0.1243X² + 0.1534X + 0.1169 (R²=0.9993). It was found that the illuminance ratio at the central part of the model space was low because the illuminance of the central part of the work plane was higher than that of the side of room. The results of this study could be utilized to determine the appropriate position of illuminance sensor when designing the dimming control system.