PLEA 2008 – 25 th Conference on Passive and Low Energy Architecture, Dublin, 22 nd to 24 th October 2008 475: DAYLIGHTING DESIGN FOR LOW ENERGY BUILDINGS IN SOUTH ITALY Sergio Sibilio 1* , Pasquale Falconetti, Luigi Maffei Seconda Università degli Studi di Napoli, Built Environment Control Laboratory Ri.A.S & Department DCP, Aversa (CE), Italy sergio.sibilio@unina2.it 1* Seconda Università degli Studi di Napoli, Built Environment Control Laboratory Ri.A.S & Department IDEAS Industrial Design Ambiente e Storia, Aversa (CE), Italy Seconda Università degli Studi di Napoli, Built Environment Control Laboratory Ri.A.S & Department DCP, Aversa (CE), Italy Abstract The preliminary study for two low energy buildings are presented. The buildings will be built in South Italy, and their design process has taken into account all those measure related to energy savings: Italian regulation on building energy performance, the renewable energy employment, both thermal and photovoltaic systems, and finally a comprehensive study of daylight impact on architectural choices; to this aim have been considered both the direct solar radiation and the sky vault contribution. In particular the daylighting analysis has been performed by models and software simulation used throughout the architectural design process to help make decisions about the natural lighting conditions and for studying distribution of daylight across spaces, luminance evaluation and quantitative measurement of daylight levels. The research developed at the Built Environment Control Laboratory RiAS, at Architecture Faculty of Seconda Università di Napoli, has involved, by several steps, the available “tools” for the assessment of daylighting contribution in a lighted environment. The first step has considered the models physical simulation by means of ECOTECT and RADIANCE daylighting analysis; this “tools” have carried out the design of solar shading devices and fenestration optimization in terms of size and position. Successively have been considered scale models that were tested inside a mirror sky box (3m x 3m) with banks of fluorescent lamps behind a translucent ceiling; this was used to reproduce the CIE standard overcast sky distribution, under which have been acquire data on internal illuminance levels, the related daylight factor and luminance distribution of internal surface. To this aim the acquisition was performed by photometric heads for scale model and luminance measuring camera; the acquired data were then compared with the physically accurate software simulation results to validate the simulation procedure and to determine the daylighting features of the architectonical solutions proposed and the potential savings due to daylight. Keywords: daylighting, daylight factor, shading device, Ecotect, artificial sky, scale model. 1. Introduction The use of daylight in buildings is widely accepted as one of the important strategies to reduce overall energy use. Apart from its numerous positive health and psychological effects, daylight is a free, renewable natural resource and a high efficacy light source. Daylight also provides a continuous spectrum of light, which enhances visual performance. People tolerate much lower illuminance levels of daylight than artificial light, particularly in diminishing daylight conditions at the end of the day [1]. On the other hand modern building design is a complex and demanding process. To add to a quite extensive list of design considerations, there are increasing client and regulatory pressures to produce higher performing and more energy efficient buildings. To this aim decisions made at the very earliest stages often have the greatest impact on the overall performance of a project. In our work we have considered two case studies related at two low energy buildings that will be built in south Italy, the first in Casaldianni (BN) and the second one in Pomigliano d' Arco (NA). For such localities, the climatic conditions during all the period of the year remain mild, becoming rigorous climate only in the extreme seasons like December o July. In this case the bioclimatic planning plays a fundamental role, because through appropriate architectonic choices and using strategies for the exploitation of resources tied to territorial characteristics it is possible to achieve energy savings. So, the design process has taken into account all those measure related to energy savings: Italian regulation on building energy performance, the renewable energy employment, both thermal and photovoltaic systems, and finally a comprehensive study of daylight impact