Gap inner pressures in multi-storey double skin facades

Double-skin façades (DSF) are used as an architectural solution to improve indoor comfort being characterized by having at least two membranes between the interior occupied space and the exterior environment, separated by an air gap where the shading devices lie. The pressure within the gap plays an important role on (i) the glazing structural safety; (ii) the shaft ventilation, in particular if a natural ventilation scheme is implemented, but also to promote an efficient gap air change, and (iii) the safety of maintenance staff, especially when windows may be opened to the interior. Although there are several DSF typologies only the multi-storey case, where no horizontal or vertical partitioning exists between the two skins, will be analysed in this paper. Nevertheless, there are still a number of possible layouts for multi-storey DSF that might impose different pressure distributions within the gap. This paper refers to a set of wind tunnel tests made over a building model with different multi-storey DSF layouts—from open on all edges to fully lateral closure and from narrow to wide gap depths, for an extended range of wind directions. The experimental data showed a layout dependent inner wall pressure distribution that may be considerably different from the unsheltered building.