Performance comparison of different filters based on fibre optic lighting systems and evaluation of architectural lighting effects

Abstract

Plastic optical fiber lighting is a feasible green lighting method for buildings. This study first derives a mathematical model for the focused light energy absorbed by optical fibers. Based on the variable relationships in the mathematical model, the cooling mechanism of plastic optical fibers was obtained. Secondly, a dual-axis automatic sun-tracking concentrating lighting equipment capable of carrying nine Fresnel lenses was designed. The equipment was used to compare the filtering and cooling effects of two types of filter devices: infrared filters and heat-insulating film. The cooling and lighting effects of these two types of filter devices were also evaluated. Subsequently, the impact of fiber loops on lighting was discussed. Finally, the b2 and b3 modules of the dual-axis automatic sun-tracking concentrating lighting equipment were applied in dark stairwells. The results indicate that the temperature of optical fibers can be reduced by using filtering devices and enhancing heat radiation and convection on the surface of optical fibers. Infrared filters exhibit better cooling and lighting effects than heat-insulating film. Looping the fiber cable reduces the effect of fiber lighting, and the higher the number of loops, the higher the loss of fiber lighting. The dual-axis automatic sun-tracking concentrating lighting equipment increased the illuminance value in the stairwells to over 50 lux, showing great application potential in architectural lighting.