Experts Say Air Ventilation Is Far More Than Cracking A Window, As Students Return To The Classroom

Mar 15, 2021

Just open a window. That was priority one of the CDC’s first air filtration guidance last month.

But some classrooms just don’t have windows to crack open as thousands of Illinois students are returning to classrooms. The state is also relaxing social distancing rules, allowing more students to pack into classes. 

The DeKalb School District has about 102 classrooms without windows; Sycamore has 58. 

Dan Larsen runs campus safety and operations at Waubonsee Community College. He’s been responsible for revamping their air systems to combat COVID-19. He says even if rooms don’t have windows, there’s still plenty they can do, like improving HVAC systems. Clean air and ventilation go way beyond cracking a window on a nice day.

“You want to have the best filtration you can on your system -- that's number one. Number two, you want to run the maximum amount of outside air you can and still balance the building and still be economically efficient,” he said.

Larsen says their HVAC is a closed system with fresh air intakes. So, they don’t even want windows wide open that would bring in pollen.

“One of the first things we did was dramatically increase the airflow. Under normal conditions, building air in a room needs to turnover about 15 times an hour,” he said. “There's an intake, and it's run through the air handling system, it's filtered, and then it's introduced back in the building.”

Now air turns over up to 25 times an hour. To pair with more air, they also installed the smallest filters they could fit. 

His top advice for schools without as many windows is to update their HVAC system and filters. 

There’s also plenty of air cleaning technology for schools that can afford it. Waubonsee has ultraviolet systems using UV lights to sanitize the air. 

Every building is different, and open windows do help for schools that don’t have as many resources, but some scientists penned a letter asking the CDC to establish stricter air standards as more students crowd into classrooms. 

Larsen also stresses that the best thing you can do is wear your own air filtration system -- AKA an N95 mask.