ABSTRACT
According to the World Health Organization (https://covid19.who.int/), more than 651 million people have been infected by COVID-19, and more than 6.6 million of them have died. COVID-19 has spread to almost every country in the world because of air travel. Cases of COVID-19 transmission from an index patient to fellow passengers in commercial airplanes have been widely reported. This investigation used computational fluid dynamics (CFD) to simulate airflow and COVID-19 virus (SARS-CoV-2) transport in a variety of airliner cabins. The cabins studied were economy-class with 2-2, 3-3, 2-3-2, and 3-3-3 seat configurations, respectively. The CFD results were validated by using experimental data from a seven-row cabin mockup with a 3-3 seat configuration. This study used the Wells-Riley model to estimate the probability of infection with SARS-CoV-2. The results show that CFD can predict airflow and virus transmission with acceptable accuracy. With an assumed a flight time of 4 h, the infection probability was almost the same among the different cabins, except that the 3-3-3 configuration had a lower risk because of its airflow pattern. Flying time was the most important parameter for causing the infection, while cabin type also played a role. Without mask wearing by the passengers and the index patient, the infection probability could be 8% for a 10-h, long-haul flight, such as a twin-aisle air cabin with 3-3-3 seat configuration.
ABSTRACT
According to the World Health Organization (https://covid19.who.int/), more than 651 million people have been infected by COVID-19, and more than 6.6 million of them have died. COVID-19 has spread to almost every country in the world because of air travel. Cases of COVID-19 transmission from an index patient to fellow passengers in commercial airplanes have been widely reported. This investigation used computational fluid dynamics (CFD) to simulate airflow and COVID-19 virus (SARS-CoV-2) transport in a variety of airliner cabins. The cabins studied were economy-class with 2-2, 3-3, 2-3-2, and 3-3-3 seat configurations, respectively. The CFD results were validated by using experimental data from a seven-row cabin mockup with a 3-3 seat configuration. This study used the Wells-Riley model to estimate the probability of infection with SARS-CoV-2. The results show that CFD can predict airflow and virus transmission with acceptable accuracy. With an assumed flight time of 4 h, the infection probability was almost the same among the different cabins, except that the 3-3-3 configuration had a lower risk because of its airflow pattern. Flying time was the most important parameter for causing the infection, while cabin type also played a role. Without mask wearing by the passengers and the index patient, the infection probability could be 8% for a 10-h, long-haul flight, such as a twin-aisle air cabin with 3-3-3 seat configuration.
ABSTRACT
Airborne transmission of infectious diseases through air travel has become a major concern, especially during the COVID-19 pandemic. The flying public and crew members have long demanded better air quality and thermal comfort in commercial airliner cabins. This paper reviewed studies related to the airliner cabin air environment that have been published in scientific journals since 2000, to understand the state-of-the-art in cabin air environment design and the efforts made to improve this environment. In this critical review, this paper discusses the challenges and opportunities in studying the cabin air environment. The literature review concluded that current environmental control systems for airliner cabins have done little to stop the airborne transmission of infectious diseases. There were no reports of significant air quality problems in cabins, although passengers and crew members have complained of some health-related issues. The air temperature in cabins needs to be better controlled, and therefore, better thermal comfort models for airliners should be developed. Low humidity is a major complaint from passengers and crew members. Gaspers are used by passengers to adjust thermal comfort, but they do not improve air quality. Various personalized and displacement ventilation systems have been developed to improve air quality and thermal comfort. Air cleaning technologies need to be further developed. Good tools are available for designing a better cabin air environment.
Subject(s)
Air Pollution, Indoor , Air Pollution , COVID-19 , Communicable Diseases , Humans , PandemicsABSTRACT
A COVID-19 outbreak occurred in May 2020 in a public housing building in Hong Kong - Luk Chuen House, located in Lek Yuen Estate. The horizontal cluster linked to the index case' flat (flat 812) remains to be explained. Computational fluid dynamics simulations were conducted to obtain the wind-pressure coefficients of each external opening on the eighth floor of the building. The data were then used in a multi-zone airflow model to estimate the airflow rate and aerosol concentration in the flats and corridors on that floor. Apart from flat 812 and corridors, the virus-laden aerosol concentrations in flats 811, 813, 815, 817 and 819 (opposite to flat 812, across the corridor) were the highest on the eighth floor. When the doors of flats 813 and 817 were opened by 20%, the hourly-averaged aerosol concentrations in these two flats were at least four times as high as those in flats 811, 815 and 819 during the index case's home hours or the suspected exposure period of secondary cases. Thus, the flats across the corridor that were immediately downstream from flat 812 were at the highest exposure risk under a prevailing easterly wind, especially when their doors or windows that connected to the corridor were open. Given that the floorplan and dimension of Luk Chuen House are similar to those of many hotels, our findings provide a probable explanation for COVID-19 outbreaks in quarantine hotels. Positive pressure and sufficient ventilation in the corridor would help to minimise such cross-corridor infections.