Are special filters worth it? School districts differ on addressing air circulation during pandemic

DURHAM, N.C. (WTVD) -- Some Triangle-area school districts are investing in air filters as students return for in-person instruction.

Durham Public Schools posted on Facebook that the district purchased $800,000 worth of air filters that can capture airborne viruses and bacteria from coughs and sneezes.

"Our facilities services staff, our maintenance crews have been with our HVAC contractors evaluating our systems, making sure that we have proper ventilation and filtration," said Durham Public Schools Chief Operating Officer Dr. Julius Monk during a news conference this week. "Not only have we been consorting with medical doctors, we've also been talking with mechanical engineers, talking about what are some of the additive things that we can do in our facilities to help mitigate the spread and the transmission of COVID-19."

Dr. Monk said the Merv 13 filters will arrive in the first part of December. In-person instruction starts back for elementary school students on January 20, as long as COVID-19 positivity rates fall below 4 percent for two weeks.

"In addition to that, in some of our most needy classrooms like our pre-K classrooms, our EC, self-contained, as well as our health care support areas that we're going to have in our facilities, we also ordered HEPA filter systems for every one of those spaces," Monk said.

ABC11 reached out to other districts to see what they're doing to increase ventilation at schools.

A spokeswoman for the Wake County Public School System said the district is in the process of getting more efficient air filters. Those filters are expected to arrive next month and get installed in the months after.

Cumberland County Schools sent a statement saying:

"Where we have the capability, we will increase the percentage of fresh air intake in our systems, either by centralized or manual control of dampers. Whenever possible, we will introduce fresh air by opening a window or door (when doing so does not present a safety/security risk), which can increase ventilation. We will continue providing preventive maintenance and frequent filter changes to all HVAC systems.

According to experts with the ABC Science Collaborative, studies have not shown that other alterations to ventilation systems are needed or effective in reducing COVID-19 transmission in school buildings. Cleaning and disinfecting as well as wearing masks and distancing are more effective than the focus on HVAC systems or filters. Air Purifiers, whether they be machines or HEPA filters, have not been shown, in and of themselves, to reduce the chance of transmission of COVID-19."

Johnston County Public Schools sent a statement saying:

"We do not have special air filters. We do have a company that provides a scheduled filter replacement time for each school to ensure that the filters are regularly changed for air circulation. Our staff members are also permitted to bring in their own HEPA filter type machines if they wish. We have also modified our energy schedule so that our units run more often to assist with airflow."


Teacher Kim O'Callaghan started the Families for Safe Schools Facebook page, advocating for a safe return to in-person instruction during the COVID-19 pandemic. The teacher at Cumberland County Schools said she's high risk and is concerned about the air circulation in schools when they return to in-person instruction.

"That's my biggest concern as a teacher because more and more studies are showing now that COVID is not spread through contact transmission but more through droplet," she said. "My classroom has a bunch of windows, but I'm certainly not going to be opening them when we're in the middle of say January or February. It's too cold."
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