It’s important to consider the quality of the air that you and your family breathe every day. Proper air ventilation and filtration in your living area may help to prevent illness and reduce transmission of viruses, such as COVID-19.

However, these actions alone are not enough to protect you and your family from COVID-19. They are simply additional layers of protection.

So how do you improve the air quality in your home? Here are some ideas:

Increase ventilation with outside air.

Generally, the more that indoor and outside air exchanges, the cleaner it is. This exchange lowers the risk of transmitting COVID-19.

Some ways that you can increase ventilation include:
  • Open windows or doors at opposite sides of the home, and keep interior doors open as long as weather allows to promote cross-ventilation.
  • Operate a window air conditioner fan that has an outdoor air intake vent.
  • Run a bathroom fan continuously.
  • Open the outside air intake of your heating, ventilation and air conditioning system.
  • Use indoor fans to circulate air in the home.

Use HEPA filters.

Air filters that remove small particles, such as high-efficiency particulate air (HEPA) filters, are effective in removing contaminants from the air. The most common household appliances to use HEPA filers are portable air purifiers; vacuum cleaners; and heating, ventilation and air conditioning systems, such as your furnace.

COVID-19 is not expelled on its own. It has to attach to something else to travel, such as mucus, a respiratory droplet or a piece of dust in the environment. A HEPA filter does not kill the COVID-19 virus, but the elements that can transport the virus attach to the filter so they cannot circulate in your living area.

Appliances that use HEPA filters only work when they are on, so you may need to run the fan on your furnace continuously or for longer periods of time. Don’t forget that filters need to be cleaned or replaced regularly to work effectively, according to the manufacturer’s instructions.

Use an air purifier.

When used properly, air purifiers can reduce contaminants in your air. However, they are designed to filter the air in a single room and not provide whole-house coverage.

Here are some tips on how to use a portable air filter:
  • Place the air cleaner in the room that you spend the most time in or where vulnerable people spend the most time.
  • To reduce risks of airborne transmission, direct the airflow of the air cleaner so that is does not blow directly from one person to another.

Increasing the ventilation and filtration of your home, which can improve the quality of the air, is another layer of protection against COVID-19. You should combine these strategies with other recommendations, such as physical distancing, frequent hand-washing, surface disinfection, and masks to protect yourself and your family.

Visit our COVID-19 page for vaccine updates, safe care and visitor guidelines, and trusted coronavirus information.

Paul Horvath, M.D., is an Emergency Medicine physician in Eau Claire and Menomonie, Wisconsin.


For the safety of our patients, staff and visitors, Mayo Clinic has strict masking policies in place. Anyone shown without a mask was either recorded prior to COVID-19 or recorded in a non-patient care area where social distancing and other safety protocols were followed.