An analysis of light-pipe system via full-scale measurements

Daylighting is an effective sustainable development strategy to alleviating the problems in energy and the environment, and improving the qualities for visual comfort and health. In Hong Kong, many buildings are high-rise blocks constructed close to each other resulting in severe sky obstructions. Recently, a great deal of attention has been paid to the development of natural daylight exploitation products. One invention is the light-pipe system that transports natural light efficiently from outdoor into rear part of a room. However, this innovative daylighting device is not popular in subtropical Hong Kong. The main reason for such unenthusiastic responses is the lack of local data to indicate the visual performance, energy savings and design implications. A research project was initiated to evaluate these issues. The study includes field measurements of daylight illuminance in a corridor installed a number of light pipes. The results demonstrate that the light-pipe system can provide sufficient illuminance, improve the daylight uniformity and have a high potential to reduce the electric lighting energy consumption.