Experimental analysis on a 1:2 scale model of the modified double light pipe

This paper is focused on the daylighting system named Modified Double Light Pipe (MDLP) set up by the authors and described in [1]. The authors designed the MDLP as an evolution of the DLP [38,39] with the aim of eliminating the drawbacks due to its encumbrance and the high luminance of its upper portion. They cut off its lower part and applied a circular light shelf to the system to prevent people from seeing the upper brightest portion of it. An experimental activity under real sky has been carried out for four months on a reduced scale model of the MDLP. The dynamic metrics DA, cDA, DR and U0 have been calculated on monthly basis. The results can be considered satisfactory both in terms of illuminance distribution and daylight autonomy, as well as illuminance uniformity, taking into account that the tests have been carried out in winter, under unfavorable climatic conditions. In fact, the results show that, even in winter climatic conditions, the MDLP gives a contribution to delivering daylight in the intermediate room both on sunny and cloudy days with good uniformity of illuminance distribution on the horizontal work-plan.