Assessment of residential mechanical ventilation for airborne infection control: A computational fluid dynamics approach for isolation strategy development

Ventilation plays a crucial role in influencing airflow and particle dispersion, highlighting the importance of effective systems to mitigate the spread of viruses in indoor spaces. While most research has concentrated on non-residential buildings, less attention has been given to optimizing ventilation in residential settings. This study examines a typical ventilation system in a detached house in British Columbia, Canada, using Computational Fluid Dynamics simulations to evaluate its effectiveness in reducing airborne infection risks. The study investigates eight different scenarios, varying diffuser locations (near the ceiling and floor), two types of ventilation rates based on standards, and the positioning of the infected individual while considering flow, heat, and particle dynamics. The concentration of injected and distributed particles is used to assess infection probabilities as an additional risk indicator. In addition, the Wells-Riley model is applied to quantify the infection probability. The results indicate that the location of the infected person and diffuser placement significantly impact particle dispersion and infection risk, with near-ceiling outlets generally reducing concentrations more effectively than near-floor outlets. Higher ventilation rates decrease particle concentration when diffusers are near the ceiling but can increase concentrations with near-floor diffusers due to turbulence. Optimizing diffuser placement and ventilation rates is crucial for minimizing airborne transmission in residential settings.