HEPA filters efficacy

A HEPA filter sits in corner, Sunday, Sept. 9, 2021, in a studio in Atkinson Hall on LSU's campus.

Before students returned to campus for the fall semester, LSU made a multi-million dollar investment installing HEPA filters in every active classroom to help mitigate the spread of COVID-19. But it has come to LSU's attention that many professors aren't using the HEPA filters, and some students are unplugging them amid complaints of being unable to hear in class.

While masks catch the potentially contagious droplets that come out of noses and mouths, HEPA filters catch smaller aerosols that float in the air. HEPA filters work in tandem with air conditioning units to increase ventilation, which is the primary way to combat aerosols. 

Civil and environmental engineering professor John Pardue, the director of the LSU COVID-19 wastewater testing program and the engineering representative on the Health and Medical Advisory Committee, says that studies revealed partway through the pandemic that COVID-19 could be transmitted by aerosols from a distance greater than 6 feet, the distance frequently stated as necessary for social distancing.

Pardue said that HEPA filter non-compliance is common on campus and has raised concerns among administration. 

"The last couple of weeks, either faculty are turning it off or students are going around unplugging them because they can’t hear. It’s just rampant,” Pardue said. "I haven’t been in a room where one’s been running until I walked in, in the past two weeks.” 

Pardue said he is concerned that somebody is “sabotaging the process.” He emphasized that not only was a large investment made on this equipment, but that the filters play an important part in keeping students safe, especially in older buildings with less effective air conditioning. 

“It can’t only be departments in the new buildings that are the ones that are safe,” Pardue said. “So I do appreciate that we have done this across the board.”

While Pardue said that he understands the noise the filters produce is an annoyance to both students and faculty, he urges the LSU community to follow the science. 

“This wasn’t a political thing, it’s solely a scientific thing that was revealed, and the campus realized it and said ‘we really want students to be safe.’ We could’ve used this money for something else, but they purchased all these things after a pretty careful evaluation of the quietest one we could get that would give the air exchanges we need.” Pardue said. 

“It is disappointing for people to just reject it out of hand and say ‘that’s a little noisy so I’m just not gonna have it for the class.’”

Pardue explained that whenever a room feels stuffy, it means that there’s not enough ventilation and that is when the filters need to be run. He said students shouldn’t be passive about HEPA filters’ use.

“I would strongly recommend to students that they take it into their own hands to make sure that they’re on,” Pardue said. “I wouldn’t sit in a classroom if the professor unplugged it. I wouldn’t.”

Some students, however, are not convinced the filters are necessary. 

Kinesiology freshman Cross Talley said he would feel comfortable without any COVID mitigation measures, including if HEPA filters weren't used at all.

“I’m that guy - we’re young, our immune systems can handle it,” Talley said. “If we didn’t have to wear masks or we didn’t have that air filtration system, it wouldn’t be that big of a deal to me personally. It’s a bigger risk to get COVID, of course, but I know I could survive.”

Political Science freshman Skylar Savitt said that she's not confident the HEPA filters are effective in preventing COVID.

"I feel like one air filter in the front of the class does nothing for people sitting all the way in the back," Savitt said, adding that the filters were yet another obstacle to hearing the professor and other students.

"You already have your masks, the professor is all the way in the front of the class so you can barely hear, there's really no point to add another problem for hearing," Savitt said.

University spokesman Ernie Ballard said that students can report faculty who are not following HEPA filter protocols by using the mask violation reporting form. 

"Facility Services and Building Coordinators check the filters periodically to ensure they are plugged in and working properly," Ballard said. "They are programmed and can't be shut off but can be unplugged. They are looking at ways to secure the plugs as well so they can't be unplugged by anyone."

Load comments