An Experimental Study on Improvement of Office Work Productivity by Circadian Rhythm Light

Recently, companies have been promoting energy saving by controlling off-ice environment such as temperature of air-conditioning system and lighting. However, the drop of productivity of office workers caused by the energy saving may become a big problem because it may extend labor time and increase energy consumption. In this study, the authors have proposed a new lighting control method which is expected to adjust circadian rhythm of office workers and improve their work productivity. Then, in order to evaluate the effectiveness of the proposed method, a subject experiment was conducted where 15 subjects joined for 18 days. In the experiments they were given three test sets of CPTOP (Cognitive Performance Test of Productivity) and their corresponding simulated tasks under two illumination conditions, high illumination condition as the proposed method and standard illumination condition as the control condition. The result shows that the improvement rate of the performance indexes under the high illumination condition against the standard illumination condition are 4.20% to 5.49%.