Experimental assessment of the effects of a porous double skin façade system on cladding loads

The high-efficiency façades, such as porous double skins, have become increasingly popular due to the recent technological progress in architecture. The so-called porous double skin façade (DSF) systems, which are constituted by a permeable layer over a closed inner façade, are often adopted to reduce the system energy demand. However, as expected, the porous skin alters the wind-induced pressures acting on the inner façade. Therefore, the cladding loads for such a façade system has to be accurately estimated performing wind tunnel tests. Using the low-rise buildings of the New Bocconi Campus as a case study, we present the experimental wind tunnel methodologies utilized to assess the wind-induced peak pressures acting on the inner glazed skin of the porous double skin façade system designed for the case at hands. In particular, the reduction of both the positive and negative peak pressures estimated for the inner façade is addressed when comparing the standard façade to the porous DSF case. In addition, the valuable data set of the pressure signals acquired for the porous DSF system studied, allows one to investigate the dependence of the computed peak pressures on the averaging time utilized for the extreme value estimates.