A Numerical Study of the Effect of Limited Space Air Stability on SARS-CoV-2 Spreading in a Ventilated Room

Worldwide concern has been focused on the airborne disease of the COVID-19 pandemic. This study investigated the effect of the limited space air stability on the mechanism of SARS-CoV-2 spreading in the interpersonal breathing microenvironment using an unsteady computational fluid dynamics (CFD) method. A validated numerical model was employed to simulate the transient SARS-CoV-2 releasing process from normal breathing activity. The computational domain was divided into an interpersonal breathing microenvironment and the rest macroenvironment.

CFD Modeling of Room Air Flow Effects on Inactivation of Aerosol SARS-CoV-2 by an Upper Room Ultraviolet Germicidal Irradiation (UVGI) System

Ultraviolet germicidal irradiation (UVGI) inactivates viral aerosols in indoor environments. Upper room UVGI systems use wall or ceiling mounted fixtures to create a disinfection zone above the occupied zone. The performance of upper room UVGI systems varies with indoor airflow induced by mechanical ventilation and thermal plumes from occupants, which carries contaminated air into the disinfection zone where viral aerosols are partially inactivated before circulating back into the breathing zone.

Proposed Non-infectious Air Delivery Rates (NADR) for Reducing Exposure to Airborne Respiratory Infectious Diseases

In November 2022, the Lancet COVID-19 Commission Task Force on Safe Work, Safe School, and Safe Travel released a report proposing new Non-infectious Air Delivery Rates (NADR) for Reducing Exposure to Airborne Respiratory Infectious Diseases, exceeding the current minimum standards, and aiming to help mitigate infection risk and promote health.

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Tracing of Sars-CoV-2 aerosols with tracer gases in an occupied classroom with mobile air cleaners

The placement of mobile air cleaners (MACs) in classrooms was widely discussed between parents, teachers, and authorities in Germany during the peak of Corona infections in 2020 and 2021. Measurements of mobile air cleaner efficiencies in larger laboratory rooms indicated that there are substantial efficiency differences between test re-sults in a real room compared to results measured in a standardized 28m³ well-mixed clean test room according to a standard. The test method described here overcomes the multiple problems and uncertainties of aerosol particle decay tests.

Covid airborne risk: online tool to develop healthy buildings

Airborne transmission has been widely proven to be the main means of contagion of SARS-CoV-2 (Severe Acute Respiratory Syndrome Coronavirus 2) , as multiple studies have established (Greenhalgh et al., 2021; Miller et al., 2021; Lidia Morawska & Cao, 2020; Tang et al., 2021; World Health Organization, 2021), Furthermore, the main documented COVID-19 outbreaks have occurred indoors (Qian et al., 2021; Randall et al., 2021; Wang et al., 2022), with medium and long-range transmission —beyond 1.5 m— as a especially relevant transmission way in poorly bad ventilated spaces (Li, 2021; Z.

AIRBODS: Airborne Infection Reduction through Building Operation and Design for SARS-CoV-2

The Airborne Infection Reduction through Building Operation and Design for SARS-CoV-2 (AIRBODS ) project aim is to deliver guidance on the ventilation operation and future design of non-domestic buildings and to quantify the risk of, and reduce the transmission of SARS-CoV-2 in buildings. It is doing this through experimentation, computer simulation and fieldwork supporting the guidance and tools.

REMARK: This Q&A was part of the AIVC special COVID-19 newsletter published in July 2021. To subscribe to the newsletter please click here.

REMARK: This Q&A was part of the AIVC special COVID-19 newsletter published in July 2021. To subscribe to the newsletter please click here.


The decision to open or close a bathroom window depends on other aspects such as: 1) Is it the only provision to ventilate the bathroom?, 2) Is there also an extraction mechanically or naturally? 

REMARK: This Q&A was part of the AIVC special COVID-19 newsletter published in July 2021. To subscribe to the newsletter please click here.


Opening windows almost always reduces the risk of contamination with SARS-CoV-2. But it is important to be aware of low outdoor air temperatures that could affect the comfort of occupants and exacerbate related health problems. 

REMARK: This Q&A was part of the AIVC special COVID-19 newsletter published in July 2021. To subscribe to the newsletter please click here.

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