No. 113: A more advanced energy-saving office building from Daiwa House (December 19, 2011)

Daiwa House will launch a more advanced energy-saving office building that utilizes as much outside light as possible. The company has already put the office building that conserves electricity by 50% from the level in 1990 by incorporating photovoltaic generation and heat insulation. The new office building can reduce electricity by more than 50%. It employs lighting blinds, light ducts, and double-sided light-emitting diodes based on the light guide plate of liquid crystal display. Light diffused by the lighting blind spreads to the four corners of a room, and light ducts to take in outside light are installed in the space that cannot get outside light. The light duct was developed by Sumitomo 3M.

The LED lighting was developed jointly by KoizumiLighting Technology and Sumitomo Chemical. It employs the edge light system that diffuses light using the light guide plate. It helps the light realize more natural feeling and make people feel brighter because it is double-sided illumination. It is automatically controlled by the illuminance sensor, and it can run without emitting light for four hours a day. Theoretically, it is possible to maintain the necessary level of luminance for 9.9 hours on average a day. On the rooftop, the new building has solar panels with a generation capacity of 10 kW to supply power enough to operate the lighting and air-conditioning.