STUDIES ON THE LIGHTING METHOD TO ACHIEVE BOTH ENERGY SAVING AND THE COMFORT USING LUMINANCE BASED LIGHTING DESIGN

摘要

We conducted an experiment in order to elucidate an ideal method to achieve both energy saving and the comfort in office lighting. In this report, we carried out the subjective experiments in actual office in 48 conditions of lighting and furniture, such as different average illuminance, different lighting area, adding wall-washer and some different reflectance and height of partitions. Luminance images were captured from the subject’s eye point, and converted into brightness images base on Nakamura’s method, and we tried to analyze the relationship of the perceived brightness and the brightness images. In the results, the subjective evaluation value of brightness of the room had a strong correlation with the average brightness value of vertical components such as a wall and a partition calculated from brightness image (coefficient of correlation: 0.90). There is a possibility that we can reduce the electricity consumption and get higher perceived brightness by raising the brightness of the vertical components.