Innovation in ventilated tiled roofs: the HEROTILE European Project

In ventilated roofs, the so-called Above Sheathing Ventilation (ASV) helps dissipating the excess heat in summer, thus reducing the cooling energy requirement. The ASV can be enhanced by increasing the air permeability of the tiled covering through the development of new tile shapes. This is the purpose of the Life HEROTILE European project, of which this work presents the preliminary analysis. The air permeability of a novel Marsigliese tile is analysed in comparison with the standard tile. The new design is improved with a higher sidelock and a new headlock pattern. A CFD model is then used to simulate the airflow through the tiles, solving the steady-state, incompressible fluid flow, in a 3D domain by means of the RANS-based standard k-ε model. A parametric study is conducted to analyse the variation in the air flow passing through the tile for different speeds and directions of the incident wind. The reference and new tile designs are compared in terms of air pressure drop and volumetric flow rate trough tiles. The novel shape increases the air permeability up to 100%; contrary to the standard shape, the new design allows also an increase of the air flow rate as the wind blows sideways.