Sostenibilità energetica di un elemento impiantistico integrato nell’involucro edilizio. la facciata interattiva

Double Skin Façades (DSF) are glass building envelopes highly appreciated in modern architecture because they are considered to be able to inspire more contact with outdoor environment and the idea of "modernity" and "transparency" for the activities in the building. These characteristics are frequently appreciated in office buildings. The ventilation of the glass cavity is at present a complex problem that must be solved studying the different cases and typologies with the aim of high efficient and energy sustainability design.. Actually, a non-accurate design approach could generate, mainly in DSF systems with natural ventilation, overheating phenomena and reduced performances for the envelope and increased energy consumption in the connected building-plant system, casting shadows on the real efficiency of these building systems. This worst condition is frequent at Mediterranean climate, characterized by long summertime with high air temperature, relative humidity and solar radiation values. In this research a comparison between overall energy performances of two different façade solution is proposed: a traditional system with natural ventilation and an mechanically ventilated interactive façade connected to an HVAC system, applied to a test building in Florence. Dynamic simulations highlight the efficiency of the mechanically ventilated façade and benefits provided by this interactive envelope transformed in a thermal buffer. The integration with HVAC system makes the façade a real plant system component that, in different seasons, reduces energy consumption and in wintertime provides additional energy recovery for the pre-heating of external fresh air.