RAPID: Energy-Efficient Disinfection of Viral Bioaerosols in Public Spaces: Vital for Lifting of the “Stay-at-Home” Orders during the Covid-19 Outbreak

该项目将提供一个分析框架，以评估在公共场所（包括校车、教室和零售店）减少COVID-19病毒生物气溶胶感染风险的可能性。无论是否同时在室内，离感染者近或远的人员都可能被病毒生物气溶胶感染。如果上层房间杀菌紫外线（UR-GUV）光与空气和表面上的生物气溶胶有效相互作用，则可以提供相对较小的能量足迹的实时空气消毒解决方案。该项目将开发和传播一个开源数值分析框架，包括评估UR-GUV消毒情况，并在网上公开发布，为帮助控制COVID-19在公共场所通过空气传播的感染提供有用的免费资源。有效、实时、可持续的空气室内消毒工程解决方案是帮助防止COVID-19传播的重要预防措施，特别是在努力重启国家经济的背景下。该项目将开发基于计算流体动力学（CFD）的数值方法，以重现病毒生物气溶胶通过室内气流传播、被排气清除、被UR-GUV灭活、被居住者吸入、沉积在不同空间尺度、通风系统、人口规模和密度的公共空间表面的过程。本项目还将优化吊扇的应用，提高UR-GUV消毒效果。该研究将为病毒气溶胶引起的感染风险以及UR-GUV对病毒生物气溶胶污染表面的感染控制提供新的见解。此外，该项目将考虑两种UV-C光源，一种是传统的汞蒸气UV-C灯（UV-C- mv），另一种是UV-C- led，以提高其能源效率。在消毒、能源效率和运行成本方面对两种UV-C源进行比较，有望实现可持续的UR-GUV解决方案，以最大限度地降低公共场所的感染风险。该奖项反映了美国国家科学基金会的法定使命，并通过使用基金会的知识价值和更广泛的影响审查标准进行评估，被认为值得支持。

This project will provide an analytical framework to assess potential reduction of infection risks from COVID-19 viral bioaerosols in public spaces, including school buses, classrooms, and retail stores. Viral bioaerosols may cause infection for occupants staying both near and far away from infected people, whether staying indoors at the same time or not. Upper-room germicidal ultraviolet (UR-GUV) light can provide a real-time air disinfection solution with a relatively small energy footprint if its light effectively interacts with the bioaerosol both in the air and on surfaces. This project will develop and disseminate an open-source numerical analytical framework including assessment of UR-GUV disinfection and make it publicly available online to provide a free resource useful for helping to control the spread of airborne COVID-19 infections in public spaces. An effective, real-time, and sustainable engineering solution for air indoor space disinfection is an important precaution to help prevent the spread of COVID-19, particularly in the context of efforts to restart the nation's economy. The project will develop numerical methods based on Computational Fluid Dynamics (CFD) to reproduce the processes for viral bioaerosols spread by indoor airflow, removed by exhaust, inactivated by UR-GUV, inhaled by the occupants, and deposited onto surfaces in public spaces of varied spatial scales, ventilation systems, as well as population size and density. This project will also optimize the application of ceiling fans to improve UR-GUV disinfection efficacy. The investigation will provide new insight on infection risk due to viral aerosols and infection control by UR-GUV for surfaces contaminated by viral bioaerosols. In addition, the project will consider two UV-C sources, one by traditional mercury vapor UV-C lamps (UV-C-MV) and another by UV-C-LED for their energy efficiency. The comparison of the two UV-C sources in terms of disinfection, energy efficiencies, and operation cost holds promise for a sustainable UR-GUV solution for minimizing infection risk in public spaces.This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.