HOLIGILM: Hollow light guide interior illumination method – An analytic calculation approach for cylindrical light-tubes

Assessment of tubular light guides with respect to building physics

“…5 It was developed to assess the amount of the visible light transmitted by straight tubular light guides. It is simple to use, fast and it provides a graphical output.…”

Modeling the aerosol effects on the light field below a tubular-pipe: A case of clear sky conditions

“…Another problem is that N is a function of both zenith angle and azimuth angle of a light beam and also depends on the point in which the beam intersects the upper interface of a light-pipe. Following the analytical model originally published in 2008 by Kocifaj et al (2008a), the luminous flux crossing the circular interface at the light-tube base can be written in form…”

“…As a consequence, the effect of light scattering on the light field below a pipe is difficult to predict. In contrast, the sunlight can be treated as parallel beams with zenith distance conserved in the process of internal reflections in a vertically oriented cylindrical tube (Kocifaj et al, 2008a). The number of internal reflections in the tube can be estimated quite well for the sunbeams due to their directionality, while the light scattered in the atmosphere is received from the whole sky vault.…”

Transmission illuminance proxy HDR imaging: A new technique to quantify luminous flux

“…Cylindrical mirrored light pipes 25 mm in diameter were used in the experiments [6]. The second paper presented a theoretical formulation and gave example output in the form of predicted contours showing the luminous flux emerging from the light pipe [7]. The TIP-HDRI technique described here allows measurements to be carried out on a quantitative basis and for full-size light-pipes, improving greatly on the method used by Swift et …”