COvid-19 Transmission Risk Assessment Case Studies - education Establishments

学校正计划在9月份重新开学，随着最近对新冠肺炎通过空气传播的认识的提高，迫切需要监测这一情况，并就通风最佳做法提供指导。预计天气将变得更凉爽，这一点得到了强调，因为维持高新风通风流量与能耗和乘员舒适度之间将存在冲突。我们将量化新冠肺炎通过空气在学校传播的风险，并评估缓解措施的有效性，方法是开发技术，评估在特定室内空间感染的绝对风险，使用中小学实地研究，并辅之以实验室实验和计算流体动力学，以阐明导致空气传播的流动模式。所产生的理解将为感染模型的最新发展奠定基础，以预测学校内空气传播的可能性。该项目将减少与空中传播路线相关的不确定性，并为评估缓解措施提供证据。我们将调查的情景包括通风、屏风的使用、教室布局和入住率的变化。该方法将促进在办公室、餐馆、商店等领域的应用。空气传播感染是通过重新呼吸的空气发生的，其浓度可以通过测量二氧化碳直接推断。室内气流受窗户或通风口位置、居住者/设备升起的热量以及人员移动造成的干扰的强烈影响。因此，需要在实验室和CFD中准确地表示这些过程，以解释目前在学校收集的监测数据，这些数据通常是单点测量。

Schools are planning to re-open in September and with the recent increased awareness of airborne transmission of Covid-19, there is an urgent need to monitor the situation and to provide guidance on ventilation best practice. This is emphasised by the expected onset of cooler weather when there will be a conflict between maintaining high fresh air ventilation flows and energy consumption and occupant comfort. We will quantify the risk of airborne COVID-19 transmission in schools and evaluate the effectiveness of mitigation measures, by developing techniques to assess the absolute risk of infection in a given indoor space, using field studies in primary and secondary schools, complemented by laboratory experiments and CFD to elucidate the flow patterns responsible for airborne transport. The understanding generated will underpin recent developments in infection modelling to predict the likelihood of airborne transmission within schools. The project will reduce the uncertainties associated with airborne transmission routes and provide evidence to evaluate mitigation measures. The scenarios we will investigate include changes to ventilation, use of screens, classroom lay-out and occupancy profiles. The methodology will facilitate application to offices, restaurants, shops etc. Airborne infection occurs through re-breathed air, the concentration of which can be directly inferred from measurements of CO2. Indoor flow is strongly affected by the locations of windows or vents, the heat rising from occupants/equipment and disturbances caused by people movement. Thus, accurate representations of these processes in the laboratory and CFD are needed to interpret the monitoring data currently collected in schools, which are typically single point measurements.