A Japanese company, Nikken Sekkei Ltd., has come up with a novel way to utilize duct work to increase light in buildings. Instead of traditional galvanized metal, the ducts have highly reflective mirrored surfaces to direct light into the interior of buildings. This passive technology is being used by Toyota in its main headquarters to introduce light into a basement cafeteria using the ducts.
Advantages of using natural light conveyed by mirrored surfaces are obvious. Besides the more pleasant aspect of being in natural light, with no energy required to light windowless interior spaces, buildings can greatly decrease power requirements during daylight hours.
The technology has received major awards in Japan from the Association of Building Engineering and Equipment, the Japan Aluminium Association, the Illuminating Engineering Society of North America and the Illuminating Engineering Institute of Japan.