ABSTRACT
Under the global landscape of the prolonged COVID-19 pandemic, the number of individuals who need to be tested for COVID-19 through screening centers is increasing. However, the risk of viral infection during the screening process remains significant. To limit cross-infection in screening centers, a non-contact mobile screening center (NCMSC) that uses negative pressure booths to improve ventilation and enable safe, fast, and convenient COVID-19 testing is developed. This study investigates aerosol transmission and ventilation control for eliminating cross-infection and for rapid virus removal from the indoor space using numerical analysis and experimental measurements. Computational fluid dynamics (CFD) simulations were used to evaluate the ventilation rate, pressure differential between spaces, and virus particle removal efficiency in NCMSC. We also characterized the airflow dynamics of NCMSC that is currently being piloted using particle image velocimetry (PIV). Moreover, design optimization was performed based on the air change rates and the ratio of supply air (SA) to exhaust air (EA). Three ventilation strategies for preventing viral transmission were tested. Based on the results of this study, standards for the installation and operation of a screening center for infectious diseases are proposed.
ABSTRACT
In this study, to fundamentally solve the risk of cross-infection in screening centers responding to infectious diseases, a new non-contact screening center was developed that supplemented the problems of existing screening centers. Numerical analysis was performed on the effectiveness of a ventilation system to remove viral aerosols and prevent cross-infection. Moreover, full-scale field measurements and SF6 tracer gas simulating viral aerosol was used under the same conditions as it was for the numerical analysis, comparison, and verification when CFD simulations were performed. Currently, COVID-19 screening centers operating in Korea can be divided into five types;the risk of cross-infection is very high due to its structure where the movement of medical staff and suspected patients cannot be separated. As a result of the CFD simulation on the ventilation system of a non-contact screening center, among the 3,000 particles generated from a patient, not a single particle was transmitted from the specimen collection booth to the adjacent examination room. More than 99% of the particles were removed by the ventilation system after 559 seconds. As a result of the in-situ measurement, the concentration of SF6 gas generated in the specimen collection booth was effectively reduced by the ventilation system. Additionally, the SF6 gas was not detected in the examination room due to the maintenance of an appropriate differential pressure. © 2022, Architectural Institute of Korea. All rights reserved.
ABSTRACT
In a recent report, the British Broadcasting Company (BBC) introduced South Korea's measures to manage COVID-19 as role model for the world. Screening centers serve as frontiers for preventing community transmission of infectious diseases. COVID-19 screening centers in Korea operate 24 h a day, always open for individuals with suspected COVID-19 symptoms. South Korea concentrated COVID-19 screening centers around cities with high population density. Advanced screening centers (models C, D, and E) proved more effective and efficient in the prevention of COVID-19 than the traditional screening centers (models A and B). Particularly, screening centers at Incheon Airport in South Korea prevent transmission through imported cases effectively. It will be important elsewhere, as in South Korea, to establish an infectious disease delivery system that can lead to 'Test-Treat-Track' using an adequate model of screening centers.