Vol. 3, Issue 3 (2019)
Sunlight permeability of an Anidolic daylighting system without compound parabolic collector
Author(s): Shun-Tsung Cheng, Jik Chang Leong
Abstract: Light pipe is an effective way to channel outdoor daylight into the interior spaces of a building. Adding an anidolic concentrator at the entry port of the Light pipe will improve daylight capture ability and reduce the overall cost per unit of delivered daylight flux. This work numerically investigates the transmission of beam and diffuse daylight through an external collector, a tubular light funnel, an internal regulator, and finally a tubular Light pipe. The regulator is used to adjust the behaviors of the light at the exit port in accordance to how the exiting light is to be used. The aim of this work is to investigate the influences of various parameters on the overall luminous performance of the daylighting system. According to current simulation results, the sunlight at an incidence angle as large as 60° can still transmit through the device. To ensure better overall performance, the size of the collector should be smaller than that of the regulator. Furthermore, if the collector is much larger than the regulator, the sunlight will be rejected by the device. Also, the reflectivity of the funnel should be kept as high as possible. Semi-spherical regulator performs better if the sunlight is more properly aligned. Otherwise, spherical one is more preferable.