Although more Americans are getting vaccinated against SARS-CoV-2, the virus that causes COVID-19, and the number of cases is dropping across the country, the Centers for Disease Control and Prevention still recommends taking precautions—particularly around non-vaccinated people and vulnerable populations.
SARS-CoV-2 typically spreads through droplets emitted when an infected person coughs or sneezes, but it can also be transmitted through tiny particles in exhaled breath. While the likelihood of the disease spreading outdoors is less than 1%, the chance of it transmitting indoors is significantly higher, especially in buildings with poor ventilation. There is evidence that tiny airborne particles can linger in indoor air for several hours and travel across distances greater than 6 feet.
The CDC has released a list of recommendations for improving and maintaining ventilation and ventilation systems in buildings. These guidelines include:
- Ensuring that ventilation systems increase circulation of outdoor air as much as possible,
- Opening windows and doors to improve circulation and increase airflow.
- Ensuring restroom exhaust fans are functional and operating at full capacity when a building is occupied.
- Inspecting and maintaining exhaust ventilation systems in areas such as kitchens and cooking areas.
- Incorporating portable high-efficiency particulate air (HEPA) fan/filtration systems to filter and enhance air cleaning.
- In non-residential settings, running the heating, ventilation, and air-conditioning (HVAC) systems at maximum outside airflow for 2 hours before and after the building is occupied.
- Generating clean-to-less-clean air movement by evaluating and repositioning as necessary the supply louvers, exhaust air grilles, and/or damper settings.
The CDC recommends consulting with an experienced HVAC professional when considering changes to systems and equipment. For a full list of CDC recommendations regarding ventilation in buildings, click here.