Development of an intelligent lighting system using LED ceiling lights into an actual office

As a demonstration, our proposed system has been introduced into actual offices in Tokyo. It consists of fluorescent lighting fixtures, light control units, microprocessors, illuminance sensors, and distributed optimization software. The lower control limit of a fluorescent light fixture is between 20% and 30%. We measured the relationship between the color temperature and the dimming range for the illuminance. The experimental results showed that the dimming range for the illuminance was narrow. To provide each worker's desired illuminance and color temperature, an LED ceiling light which can control the luminance between 0% and 100% is preferable. However, LED ceiling lights for office use have not been developed so far. The two leading light equipment makers have prototyped LED ceiling lights. We developed an intelligent lighting system using these lights and verified its effectiveness. The experimental results showed that the proposed system could provide the required illuminance and color temperature, and could achieve an energy savings of 60 to 80%. The intelligent system has a high affinity for LED lights. From the point of view of effective utilization of energy, the intelligent lighting system using LED ceiling lights showed good performance. © 2012 Wiley Periodicals, Inc. Electron Comm Jpn, 95(10): 54–63, 2012; Published online in Wiley Online Library (wileyonlinelibrary.com). DOI 10.1002/ecj.10395