Daylighting with external shading devices: design and simulation algorithms

In this paper, simplified algorithms to assess the indoor natural illuminance on a prefixed point with external fixed shading devices are presented. The main aim of the proposed approach is to simplify calculations for the two basic cases of dynamic analysis, required by advanced hourly simulation packages, and first-stage building design. The proposed method is based on the split of the internal illuminance into two components, due to the direct and diffuse sun radiations, expressed by the Solar System Luminous Efficacies (SSLEs), calculated by the package Superlite. SSLEs correlations have been tested by experimental measurements on scale models. Energetic comparisons to validate the proposed method have been carried out by an improvement of the hourly simulation program IENUS (Integrated ENergy Use Simulation). First-stage design has been tested for some Mediterranean cities.