Computational analysis of the performance of a new facade concept for wind comfort on building balconies : validation and application

High-rise buildings can cause high wind speed near ground level and on building balconies necessitating remedial action. In order to reduce wind discomfort on balconies, different measures can be taken. This paper presents the evaluation of a new second-skin facade concept to improve wind comfort at building balconies. The concept consists of a staggered semi-open second-skin facade in front of the balconies, which partly shields them from the wind. CFD simulations are performed for the building with and without second-skin facade concept. Validation is conducted using wind-tunnel measurements of surface pressure distribution on a building model with balconies. Next, the CFD results are combined with wind speed statistics and a comfort criterion to judge wind comfort on the balconies, according to the Dutch wind nuisance standard. The analysis shows that this concept is effective in providing a zone with pressure equalisation at the balconies. The related reduction in pressure gradients across the width of the facade strongly decreases the local wind speed. At many positions along the balconies this yields a wind comfort improvement of one or even two classes in the Dutch wind nuisance standard compared to the situation without implementation of this concept.