Proper ventilation is an important factor in reducing the spread of COVID-19 and other respiratory viruses. Introducing fresh air into your home, filtering the air that is there, and improving airflow can help reduce virus particles and prevent the spread of the virus. Good ventilation, along with other preventive measures, can help protect you and others from contracting and spreading COVID-19. Setting up ventilation systems to introduce fresh air and not recirculate indoor air will help eliminate virus particles. The Environmental Protection Agency (EPA) recommends upgrading filters to the highest efficiency compatible with the building's HVAC system and using air purifiers and portable air to improve overall circulation and reduce viral transmission.
Letting fresh air into indoor spaces can help eliminate air that contains virus particles and prevent the spread of coronavirus (COVID-19) and other respiratory infections, such as the flu. Most aircraft have cabin air filtration systems equipped with HEPA filters that can eliminate viruses and germs quickly, reducing the risk of exposure to any possible infectious virus or bacteria expelled by coughing or sneezing. Building operators must ensure that they channel as much outside air as required by local codes and they must program their daytime ventilation systems to operate continuously, rather than just when they heat or cool the air. However, if air circulates through the filter of a ventilation system many times per hour, that can help reduce transmission.
A simulation by the Centers for Disease Control and Prevention found that combining the use of masks and the use of portable air purifiers with high-efficiency particulate air filters, or HEPA filters, could reduce coronavirus transmission by 90%. Because the operation of your HVAC system filters the air as it circulates, it can help reduce airborne pollutants, including viruses, indoors. Experts say research shows that better indoor ventilation through portable filters and air purifiers can help reduce virus transmission in indoor public spaces. Bringing fresh air to a room and removing old, stale air that contains virus particles reduces the chance of spreading respiratory infections.
When it is not possible to introduce more fresh air, a high-efficiency particulate air (HEPA) or ultraviolet (UV) filter may be useful in some cases to reduce the risk of infection. Ventilation with recirculated air will not reduce the risk of COVID-19 unless the recirculated air passes through a filter made to remove tiny particles. Air cleaning devices are not a substitute for good ventilation, however, when good ventilation cannot be maintained, air cleaning units using HEPA filters or UV technologies could be a useful alternative to reduce airborne virus transmission.