The transport of gaseous pollutants due to stack and wind effect in high-rise residential buildings

Several outbreaks of severe infectious diseases occurred recently in high-rise residential (HRR) buildings have motivated a series of engineering investigations into possible airborne transmission routes. It is suspected that, driven by stack and/or wind effect, the polluted air may transport between flats through leakage cracks of doors and windows inside HRR buildings. The pure stack effect has been quantitatively studied and reported in a previous paper. This study further investigates the temporal and spatial distribution of gaseous pollutants due to combined stack and wind effect in an HRR building in Shanghai (China) with doors and windows closed. A well-established multi-zone (CONTAM) model, based on reliable boundary conditions from CFD simulations, is used to analyze the airflow movements and pollutant transport between flats via door and window leakage cracks under different scenarios. It is found that the combined stack and wind effect can cause the pollutant spread in both vertical and horizontal directions. In general, the concentrations in the top rooms are about 3-4 orders of magnitude lower than in the source room in a 33-floor building, and the concentrations on the leeward side are mainly higher than on the windward side before steady state. The effects of the outdoor/indoor temperature difference, wind field, air tightness level and source location are quite complicated due to the interaction between physical forces and the building shape. Despite the complexities, these findings have many implications that cannot be overlooked for the infectious disease control and ventilation design in HRR buildings. (C) 2015 Elsevier Ltd. All rights reserved.

近期在高层住宅（HRR）建筑中发生的几起严重传染病疫情，促使人们对可能的空气传播途径进行了一系列工程调查。据推测，在烟囱效应和/或风力作用下，污染空气可能会通过高层住宅建筑内门窗的缝隙在公寓之间传播。单纯的烟囱效应已在先前的一篇论文中进行了定量研究和报道。本研究进一步调查了在中国上海的一栋门窗关闭的高层住宅建筑中，由于烟囱效应和风力共同作用导致的气态污染物的时空分布。基于计算流体动力学（CFD）模拟所提供的可靠边界条件，一个成熟的多区域（CONTAM）模型被用于分析不同情景下通过门窗缝隙在公寓之间的气流运动和污染物传输。研究发现，烟囱效应和风力的共同作用会导致污染物在垂直和水平方向上扩散。一般来说，在一栋33层的建筑中，顶层房间的污染物浓度比污染源房间低约3 - 4个数量级，并且在达到稳定状态之前，背风侧的浓度主要高于迎风侧。由于物理力和建筑形状之间的相互作用，室外/室内温差、风场、气密程度以及污染源位置的影响相当复杂。尽管情况复杂，但这些研究结果对高层住宅建筑的传染病防控和通风设计具有不可忽视的诸多启示。（C）2015爱思唯尔有限公司。保留所有权利。