Dai Hui, Zhao Bin
Department of Building Science, School of Architecture, Tsinghua University, Beijing, 100084, China.
Beijing Key Laboratory of Indoor Air Quality Evaluation and Control, Tsinghua University, Beijing, 100084, China.
Build Environ. 2022 Apr 1;213:108864. doi: 10.1016/j.buildenv.2022.108864. Epub 2022 Feb 4.
Portable air cleaners (PACs) can remove airborne SARS-CoV-2 exhaled by COVID-19 infectors indoor. However, effectively locating PAC to reduce the infection risk is still poorly understood. Here, we propose a simple model by regressing an equation of seven similarity criteria based on CFD-modeled results of a scenario matrix of 128 cases for office rooms. The model can calculate the mean droplet nucleus concentration with very low computing costs. Combining this model with the Wells-Riley equation, we estimate the airborne infection risk when a PAC is located in different positions. The two similarity criteria, and , are critical for characterizing the effect of the position and airflow rate of PAC on the infection risk. An infection probability of less than 10% requires to be larger than 144 and to be larger than 0.001. These criteria imply that locating PAC in the center of the room is optimal under the premise that the airflow rate of PAC is greater than a certain level. The model provides an easy-to-use approach for real-time risk control strategy decisions. Furthermore, the placement strategies offer timely guidelines for precautions against the prolonged COVID-19 pandemic and common infectious respiratory diseases.
便携式空气净化器（PACs）可以去除室内新冠病毒感染者呼出的空气中的 SARS-CoV-2。然而，如何有效放置 PAC 以降低感染风险仍知之甚少。在此，我们基于 128 个办公室房间场景矩阵的计算流体动力学（CFD）模拟结果，通过回归一个包含七个相似性标准的方程，提出了一个简单模型。该模型能够以非常低的计算成本计算平均飞沫核浓度。将此模型与威尔斯 - 莱利方程相结合，我们可以估算当 PAC 位于不同位置时的空气传播感染风险。两个相似性标准，即 和 ，对于表征 PAC 的位置和气流速率对感染风险的影响至关重要。感染概率小于 10%要求 大于 144 且 大于 0.001。这些标准意味着在 PAC 的气流速率大于一定水平的前提下，将 PAC 放置在房间中央是最优的。该模型为实时风险控制策略决策提供了一种易于使用的方法。此外，这些放置策略为防范新冠疫情长期化和常见传染性呼吸道疾病提供了及时的指导方针。
