本文
No.5（2002）11.Lighting electric power reduction by the window device of prism system for daylighting
Toshihide IWANAGA, Tetsunori JITSUKAWA and Tetsuo YAMAMOTO
The window device of prism system for daylighting uses sunlight for indoor lighting and indoor heating using the refraction effect of light from a transparent prism plate installed in a side window. In order to estimate the lighting effect of the window equipment, illuminance distribution on working plane and luminance of the window were measured using a model of an office. As a result, regarding the glare-control-type prism system,which combines a louver with a prism plate, it is expected that the working plane illumination of room depths of 200lx, 500lx, and 1000lx or more are obtained respectively at the southern point of the summer solstice, the vernal/the autumnal equinox and winter solstice with the discomfort glare of the window controlled. By combining the dimmer function with this system, an annual reduction of 17% of electric power used for lighting can be achieved.
Keywords
Prism system, Daylighting, Sunlight, Discomfort glare
