On environmental sustainability of ventilated façades in Italy

The aim of the paper is to address some environmental issues about the use of ventilated walls (or façades) in Italy for commercial and/or residential buildings . Particularly, the question is if ventilated façades (VF) represent an environmentally sustainable solution for some kind of buildings and architecture. Nowadays, ventilated walls are widely used in the form of back ventilated non loadbearing enclosures. Precise calculations on their performances are very difficult to carry out and usually not accomplished. In recent years some sophisticated analytical methods of Computational Fluid Dynamics, based on finite differences or other sophisticated techniques, have been proposed. In these cases, as a precise understanding of the components (materials and geometry of the enclosure system) and the knowledge of pressure and wind speed and direction are always required, it is always difficult to extend the results to generic situations. Besides, no simple or efficient method to address the effects of ventilation on internal comfort and energy consumption is used in Italy by Building Regulations. On top of that, the integration of the enclosure with the overall environmental behaviour of the building is often not taken into consideration. The consequence is that the contribution of the ventilation is generally not considered. VF become very well-publicized and attractive solutions more than environmentally conscious elements.