Daylighting Distribution in Atrium Spaces with the Glazing as a Lambertian Light Source: Part 1-The four-sided type

Computer modeling of daylight distribution in the top-lit, four-sided atrium are carried out to further our understanding of the behaviour of daylight inside different atrium spaces and to provide quick and user friendly tools to evaluate the daylighting performance of the atrium during early design stages when most of the attributes of the atrium boundaries are not yet determined. In this study a systematic evaluation of the daylighting efficiency of atrium buildings is undertaken and the affect of the main design parameters most susceptible to impact the daylighting performance is examined. These parameters are the wall reflectance and the geometric proportions of the atrium, described by the Plane Aspect Ratio (PAR) and the Section Aspect Ratio(SAR). The results of our simulations are compiled into tables where Daylighting Efficiency Factors(DEFs) are given for some critical locations inside the atrium.