Abstract :
A physical model for interior illuminance calculation HOLIGILM applied to cylindrical skylights was developed. Based on the raytracing
between the diffuser of a tubular skylight and the sky vault including the Sun, the light transmission coefficient of the cover dome
and of the interior diffuser with the high light-guide reflection, as well as taking into account the geometry of the interior, the resulting
illuminance of the working plane can be analysed. As the model is strictly physical it allows to study influences of optical properties of
tubular skylights (dome, tube and diffuser) on the interior daylight illuminance distribution specifying the luminance distribution on the
hollow light-guide diffuser. The standard sky luminance distributions adopted ISO 15469:2004 and the new solar luminance and constant
were included into the evaluation concept of tubular skylight. In addition to the original formulae some practical examples of the predicted
illuminance on the working plane are also presented in this paper.
2007 Elsevier Ltd. All rights reserved
