Plaster ventilated façade system for renovating modern and ancient buildings. A CFD analysis

In the past decades several researches have been related to energy saving and emissions reduction. The technologies that exploit passive natural ventilation, like ventilated roofs and fa ades, have been recognized as the effective methods to provide energy saving and comfort. Ventilated fa ades represent dry assembled coating systems for buildings, traditionally made of panels in different materials. Very few ventilated fa ade systems with plaster finishes are already present on the building market. The potentiality of their design solution can be considered, e.g., when an historic building has to be recovered, since they can enhance the energy efficiency of building without changing its appearance. CFD simulations have been carried out by the authors in order to analyze the thermal energy behavior of a ventilated fa ade system with a plaster finishing and for comparing the benefits derived from its use to the corresponding unvented insulated fa ade. The ventilated fa ade shows a relevant energy saving thanks to the effect of ventilation: a reduction of 70% of heat flux was achieved, furthermore, a reverse conductance calculation showed relevant differences with the same calculated by thermo-physical material properties, since in this last calculation the heat and mass transport effect are not considered.