Numerical robustness analysis of natural and mechanical smoke extraction systems for buildings

Buildings' smoke extraction systems are commonly designed according to guidelines and standards. This approach does not take all boundary conditions into account that may occur within the lifespan of a building. We introduce a novel approach for evaluating the robustness of smoke extraction systems that incorporates realistic boundary conditions by means of the Monte Carlo CFD simulation method. We use a large number of simulations with randomly generated boundary conditions and an evaluation criterion based on visibility range to assess the performance. Based on this novel approach, we compare a natural and a mechanical smoke extraction system. The simulation results show that the mean visibility range with the natural smoke extraction system is 1.3times higher. However, the mechanical smoke extraction system works sufficiently at a wider range of boundary conditions within the first five minutes after the start of a fire, which is the crucial phase of an evacuation.