Home is where we tend to feel the most safe during COVID. Yet when a family member returns from an errand, or someone decides to pay us a visit, virus particles can enter the home and accumulate in the air. That’s why we need good home ventilation to help keep the air clean during the pandemic. To improve ventilation within our homes the CDC and Environmental Protection Agency (EPA) recommend the following measures.

Increase ventilation

To increase ventilation, bring in as much fresh air as possible:

  • Open windows and screened doors unless doing so poses a safety or health risk to children or other family members (extreme cold, risk of falling, triggering asthma symptoms, etc.).
  • While it’s best to open doors and windows wide, even a slight crack can help.
  • Use a window air conditioner that has an outdoor air intake or vent, with the vent open.
  • Turn on the bathroom fan when the bathroom is in use or run it continuously if possible.

Improve the flow

Even with an open window or door, natural ventilation is limited when outdoor air is still or when indoor and outdoor temperatures are about the same. To improve natural ventilation:

  • Increase cross-ventilation by opening windows or doors at opposite sides of the home and keeping internal doors open.
  • Open the highest and lowest windows at the same time (especially on different floors).
  • For double-hung windows, open the top sash of one window and the bottom sash of another. Even when using a single window, partially opening both the top and bottom sash improves ventilation.
  • Use indoor fans in combination with open doors or windows to further increase ventilation. Place box fans or tower fans in front of windows. Use multiple fans to push air out one window and in from another. (Face a fan toward the window to blow suspect air out, away from the window to bring fresh air in.)
  • Make sure fans don’t blow air directly from one person to another to reduce the risk of airborne transmission.

Put your HVAC to work

Since HVAC systems filter the air they circulate, they can help reduce airborne contaminants, including viruses. If you have an HVAC system:

  • Run the system fan for a long as possible or even continuously. HVAC systems only filter the air when the fan is running. Most fans can run without the heating or cooling function.
  • Make sure the filter is correctly in place and consider upgrading to the highest-rated filter your system can manage.
  • If your HVAC system has one, use the energy-efficient air-to-air heat exchanger, heat recovery ventilator (HRV) or energy-recovery ventilator (ERV). These help increase ventilation.

Consider a portable air cleaner

While HVAC systems filter air throughout the home, portable air cleaners—also known as air purifiers or air sanitizers—filter air in a single room or area. When combined with other best practices recommended by the CDC, they help can protect your home. The Environmental Protection Agency (EPA) provides extensive information on air cleaners and air filters for the home.