2.1. Overview

ADS as an application of the non-imaging optics theory [3] for illumination purposes have first been introduced by Courret et al. [4], who have discussed the performance of their “anidolic light — duct” in 1998. This system is shown in Figure 1(left). Direct sunlight and diffuse daylight enters the system through a double glazing tilted towards the sky’s zenithal area. Two anidolic elements (i. e. reflective elements shaped according to the non-imaging optics theory) then redirect the entering daylight flux into the light duct with a minimum of reflexions and a minimum of rejections. At the end of the light duct, the daylight flux is released into the rear of the room and properly distributed by a third anidolic element.

This system’s performance has been thoroughly compared to other ADS by Courret in 1999 [5] and by Courret and Scartezzini in 2002 [2], who have referred to it as the Anidolic Integrated Ceiling (AIC). Its performance under different sky types (i. e. in tropical, subtropical and tempered climates) has been simulated by Wittkopf et al. in 2006 [1]. In 2007, a highly energy-efficient office lighting solution based on the AIC for a Singapore office room has been presented by Linhart and Scartezzini [6].