Effective ventilation and air disinfection system for reducing coronavirus disease 2019 (COVID-19) infection risk in office buildings

Abstract

During the COVID-19 pandemic, an increasing amount of evidence has suggested that the virus can be transmitted through the air inside buildings. The ventilation system used to create the indoor environment would facilitate the transmission of the airborne infectious diseases. However, the existing ventilation systems in most buildings cannot supply sufficient clean outdoor air for diluting the virus concentration. To reduce the airborne infection risk and minimize energy consumption, especially in existing buildings with well-mixed ventilation systems, this investigation used an ultraviolet-C (UV-C) air disinfection device (Rheem's third generation products, RM3) with 99.9% disinfection efficiency to clean air carrying the COVID-19 virus (severe acute respiratory syndrome coronavirus 2, SARS-CoV-2) which could help promote environmental sustainability and create healthy cities. This investigation assessed the impact of the RM3 UV-C units on the infection risk, the number of RM3 UV-C units required, and the strategy for decreasing the infection risk, with the use of computational-fluid-dynamics (CFD) numerical simulations. An actual office building with a combination of individual offices and workstations was selected as an example for the research. According to the numerical results, the best strategy would be to use a combination of 100% outside air and UV-C in heating, ventilation and air-conditioning (HVAC) ducts with air disinfected by the RM3 UV-C units. The infection risk in the office building could thus be reduced to a negligible level. These findings could provide theoretical basis and engineering application basis for COVID-19 epidemic prevention and control.

Energy, economic, and environmental impacts of enhanced ventilation strategies on railway coaches to reduce Covid-19 contagion risks

“…Note that a comprehensive comparison with other works in literature is not possible due to the high differences occurring among the investigated case studies. Nevertheless, the achieved outcomes are consistent with the results presented by other works on the same topic: by augmenting the outdoor airflow rate, Covid-19 contagion risk reduction up to 56% for a university facility [ 29 ], 30% for an office space [ 30 ], and 75% for an outpatient building [ 32 ] are obtained by other authors. It is worth noticing the occurring differences are mainly due to the very different case study geometry, indeed use, ventilation rates, etc.…”

“…The same outcome is obtained in the work reported in Ref. [ 30 ], where the authors propose the adoption of ultraviolet-C (UV–C) and air disinfection device (RM3) to reduce the Covid-19 contagion risk. The authors conclude that the best strategy is the combination of disinfection devices and the use of 100% outside air, leading to a Covid-19 infection risk probability reduction from 27 to 3%.…”

Prevention of Airborne Transmission of SARS-CoV-2 by UV-C Illumination of Airflow

“…One prominent application of UV light sterilization of airflow is in protecting healthcare workers during manual or mechanical ventilation [17,18], and the apparatus evaluated in these experiments was a prototype for such a system. However, the same technology can readily be scaled to accommodate much larger conduits, such as ventilation ducts [19].…”

Metabolism-based ventilation monitoring and control method for COVID-19 risk mitigation in gymnasiums and alike places

“…The World Health Organization recommends to increase the supply of fresh indoor air as an effective way to reduce the concentration of virus particles in enclosed spaces, thereby reducing the risk of infection. Therefore, effective building ventilation is essential to ensure the health and safety of occupants ( Cao et al, 2020a ; Kong et al, 2021 ; Srivastava et al, 2021 ;).…”