Development of the Intelligent Lighting System using LED Ceiling Lights into an Actual Office

As a demonstration, this system has been introduced into actual offices in Tokyo. These systems consist 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 relationships between color temperature and a dimming range of illuminance. The experimental results showed the dimming range of illuminance was narrow. To provide each worker's desired illuminannce and color temperature, the LED ceiling light, which can control the luminance between 0% and 100%, is desired. However, the LED ceiling light for the office use has not been developed so far.The two leading lighting equipment makers prototyped the LED ceiling lights. We developed the intelligent lighting system using these lights, and verified its effectiveness. The experimental results showed the proposed system could provide required illuminance and color temperature, could make energy saving of 60-80%. The intelligent system has high affinity with a LED light. From the point of view of effective utilization of energy, the intelligent lighting system using the LED ceiling lights showed a good performance.