A simple model to study ventilated facades energy performance

The aim of this work is to provide a simple and useful tool to study energy performance of different ventilated facades typology. To simulate the studied sample, a steady state energy balance has been applied to a control volume which basic equations have been solved by a finite element code with an iterative procedure. For each step x of the channel height, the different surface and air mass temperatures are calculated. The mass flow rate is evaluated as overall natural draught. Effects due to different cavity widths of the ventilation channel are investigated for winter and summer season with opened and closed ends. Comparisons show that it is possible to obtain a sensible solar cooling effect during summer, when the air cavity width of the chimney is wider than 7 cm. For wider cavities the cooling effect becomes stable. In winter, thermal insulation, provided by the closed ventilated façade is very important.