The US Centers for Disease Control and Prevention posted new recommendations Friday on the importance of good ventilation in preventing coronavirus spread in schools and daycares. Its top recommendation: Open a window.
It’s the first time the agency has separately emphasized the role ventilation plays in helping or preventing the spread of the virus, which is transmitted in tiny particles called aerosols, as well as via larger articles.
“If safe to do so, open windows and doors,” the CDC advises. “Even just cracking open a window or door helps increase outdoor airflow, which helps reduce the potential concentration of virus particles in the air. If it gets too cold or hot, adjust the thermostat. Do not open windows or doors if doing so poses a safety or health risk (such as falling, exposure to extreme temperatures, or triggering asthma symptoms),” it adds.
“Open windows in transportation vehicles. Use exhaust fans in restrooms and kitchens.”
Mask use can prevent the virus from getting into the air in the first place, the CDC said on the newly posted web page. But good ventilation is also important.
“Use child-safe fans to increase the effectiveness of open windows. Safely secure fans in a window to blow potentially contaminated air out and pull new air in through other open windows and doors,” it adds. “Consider having activities, classes, or lunches outdoors when circumstances allow.”
The new guidance also addresses heating, ventilation and air conditioning (HVAC) systems. “Set HVAC systems to bring in as much outdoor air as your system will safely allow,” it suggests. “Increase the HVAC system’s total airflow supply to occupied spaces when you can. More air flow encourages air mixing and ensures any recirculated air passes through the filter more frequently.”
Filtration is also important, but filters should not reduce airflow.