Double skin façades for warm climate regions: Analysis of a solution with an integrated movable shading system

The analysis of a glass double skin façade equipped with integrated movable shading devices is presented, employing three different modelling levels: optics of materials, fluid dynamics of the double skin façade and building energy balance; the aim is to optimize both winter and summer energy performance. The model is developed for a façade oriented towards the south and taking into account the climatic data of central Italy; the solar radiation path with its multiple reflections at the different interfaces have been taken into account employing a ray tracing method. Simulations have been validated by the comparison with data of a similar experimental apparatus and they show that the winter configuration of the proposed façade allows a satisfactory solar heat gain in spite of the presence of shading systems. In summer, the solar heat is mainly absorbed by the external part, and even if a natural convection occurs, there is no significant influence on the inner skin and on the internal environment, thus reducing building cooling requirements. The façade performance was compared with traditional enclosures such as glazed and opaque walls in an office room in central Italy, showing that in the entire year the façade proposed significantly improves the building energy behavior, especially compared to opaque walls and when the configuration with air recovery is considered. 2008 Elsevier Ltd. All rights reserved.