Experimental Investigation on Light-Thermal Effects of Solar Light Pipes Used in USTB Gymnasium under Sunny Conditions in Beijing

Experimental investigation was carried out on light-thermal effects of solar light pipes used in gymnasium of USTB under sunny conditions in Beijing. Experimental results showed that maximum of average luminance on the work plane generated by solar light pipes would achieve 300lx. People in the past on the solar light pipes studies mainly concentrated on its performance, and its impact on building thermal environment has never been reported in the literature. To promote the study of temperature performance of solar light pipes, in this paper, initial experimental study was done on temperature effect. The outside part of solar light pipes was investigated by Infrared Imaging System. The extent of increase of temperature on the surface of the capture, the dead against side was higher than the facing of a quilt, the maximum temperature difference was 8.9°C. At the juncture between sunlight capture and flashing, the temperature had large fluctuation, which the maximum value was 34.3°C. The temperature of the surface of the capture, the natural life and light-thermal effect of the solar light pipes would be influenced. The temperature generated by solar light pipes had smaller effect than electrical lighting and larger than intakes, which the maximum was 23.43°C, 153.5°C and 20.1°C. The experimental results showed that the solar light pipes have a little effect on room temperature. To improve the performance of the solar light pipes, reduce infrared solar radiation through the light pipes was one of the effective methods.