Improve Ventilation in Your Home for Safer Celebrations

Planning on bringing your family and friends over for a special gathering this winter season? Taking a few extra steps to improve ventilation (air flow) in your home can help reduce the spread of viruses like the one that causes COVID-19 so you and your loved ones can gather more safely.

When people exhale, they release small particles that can build up in the air. These particles can contain viruses—including the virus that causes COVID-19. While we don’t know how many virus particles it takes to infect a person with COVID-19, we do know that the fewer particles in the air, the better.

Improving ventilation in your home can help prevent those virus particles from accumulating in the air. Good ventilation, along with other preventive actions, can help prevent you from getting and spreading COVID-19.

You can take actions to improve ventilation in your home. Some methods may not be possible or feasible for your living situation—that’s OK.  Do what you can. Every little bit helps.

Bringing fresh, outdoor air into your home helps keep virus particles from accumulating inside. If it’s safe for you to do so, open as many windows and doors as you can to bring in the fresh air. You can also use fans to move indoor air outside.

If you live in a colder place, opening lots of doors and windows might not be comfortable. In this case, try cracking open a window, and close it if it gets too cold for you or your guests. While it’s better to open windows wide, even having a window cracked open slightly can help.

Does your home have a central heating, ventilation, and air conditioning system (also known as HVAC)? If so, you can use your HVAC to help trap virus particles while your visitors are over. Before the visit, make sure your filter has been changed within the last 3 months and fits properly in the unit. If you can, use a pleated filter (found at hardware stores)—these are more efficient than ordinary furnace filters.

If you can control the HVAC fan operation by a thermostat, make sure to set the fan to the “on” position instead of “auto” during the visit. This ensures that the fan runs continuously, even when heating or air conditioning is not on.

If you don’t have an HVAC system or just want extra filtration, consider using a portable high-efficiency particulate air (HEPA) cleaner. They are the most efficient filters on the consumer market for trapping particles that people exhale when breathing, talking, singing, coughing, and sneezing.

When choosing a HEPA cleaner, select one that is the right size for the room(s). One way to do this is to select a HEPA fan system with a Clean Air Delivery Rate (CADR) that meets or exceeds the square footage of the room in which it will be used. The larger the CADR, the faster it will clean the air. See EPA’s Guide to Air Cleaners in the Home for more information.

Exhaust fans above your stovetop and in your bathroom that vent outdoors can help move air outside. Even if your stove exhaust fan doesn’t vent outside, it can still help improve air flow and keep virus particles from staying concentrated in one place. Keep exhaust fans turned on during and for at least an hour after your guests leave to help remove any remaining virus particles that might be in the air.

CDC, in collaboration with the National Institute of Standards and Technology (NIST), created a tool to help show you how your actions can help keep virus particles from building up in your home.

To use the tool, input the actions you’re taking to improve ventilation in your home during and after people visit to show how your home’s air quality improves. Actions include using an HVAC system, using an upgraded HVAC filter, opening windows, and running a HEPA purifier.

Keep in mind that taking additional actions not included in the tool, like running exhaust fans and ventilating for an hour after visitors leave, can help further improve the quality of the air in your home.

Visit Interactive Ventilation Tool to try out the tool.