Thousands of New York City classrooms have been cleared as having adequate ventilation for safe, in-person instruction even though they do not meet the COVID-19 standards set by federal experts or recommended by building industry experts, WNYC/Gothamist has found.

A simple, green checkmark indicates whether “operational ventilation” is available in one of the 58,600 classrooms surveyed by the city’s Department of Education (DOE). As of August 29th, officials have awarded this seal of approval to 97% of these classrooms.

But the DOE classifies at least 4,000 of these approved classrooms as relying exclusively on functioning windows—a lower standard than what would be expected to prevent airborne transmission of the coronavirus indoors. If these window-only rooms lost their “operational” status, it would triple the number of classrooms currently ineligible for in-person learning this fall.

“Windows are not a reliable way for you to get outside air,” said Dr. Marwa Zaatari, a mechanical engineer and member of the Epidemic Task Force of the American Society of Heating and Air-Conditioning Engineers (ASHRAE), which is cited in Centers for Disease Control and Prevention recommendations for schools and other buildings. “Is it better than zero? Yes. But, as a ventilation engineer, can I predict how much [fresh] air you're getting at each hour of the day? The answer is no.”

Click "listen" in the player to hear more details. For a map of the schools, head to Gothamist.