Numerical and experimentala analysis on Double Light Pipe, a new system for daylight distribution in interior spaces

In this paper the authors illustrate an innovative system able to transmit daylight from the rooftop of a building, where natural light is intercepted, to hypogeal areas or rooms not equipped by windows and, contemporarily, to distribute daylight into the spaces passed through by the equipment. This technological apparatus, named “Double Light Pipe”, has been studied into the Laboratory of Technical Physics of the Faculty of Architecture, University “G. D’Annunzio” of Pescara, Italy, where a numerical and experimental analysis has been carried out. It consists of two concentric tubes: the internal one is a traditional light pipe, which transmits light from a clear collector commonly positioned on the roof top of the building, downward to underground areas where a polycarbonate diffuser is placed, while the external one lets light to enter into the locals that are positioned between the collector and the diffuser. The numerical analysis has been carried out by ECOTECT and RADIANCE softwares and the obtained results are compared each to the other and with experimental data got by a reduced scale analysis.