EAU CLAIRE — A group of UW-Eau Claire researchers have begun conducting tests to measure classroom ventilation with a goal of helping the university's effort to control transmission of COVID-19 this fall.
Two UW-Eau Claire professors and several public health and environmental studies students hauled industrial fans and a container of dry ice into a handful of Schneider Hall classrooms on Wednesday on the university campus.
After closing the doors and turning on the fans, Jim Boulter, Crispin Pierce and three of their students tracked carbon dioxide levels in the room. Special sensors started to beep as the dry ice — the solid form of CO2 — turned into the gaseous state of carbon dioxide, which was dissipated through the room by the fans. (Researchers held the rooms at about 1,000 parts per million of CO2 during the testing, Boulter said — far below a level that’s harmful to humans.)
The experiment allows the students and professors to simulate a classroom full of people exhaling carbon dioxide as they breathe, Boulter explained.
The research team is interested in how quickly the heightened CO2 levels decline, which tells them how quickly air exchanges in each room. And that can vary from room to room.
“The more air builds up, the higher the concentration of aerosol particles and (potential) virus particles we get,” said Boulter, a professor of chemistry in UW-Eau Claire’s Public Health and Environmental Studies program. “What we’re doing here is explicitly measuring the rate at which the air is turned over.”
COVID-19 spreads when an infected person exhales droplets and much smaller particles that contain the virus. The droplets or particles can be breathed in, or land on other people after a cough or sneeze, according to the Centers for Disease Control and Prevention.
While people within six feet of an infected person are the most likely to be infected, the much smaller aerosol particles also pose a danger. The smaller particles carry virus and can transmit infection, and are small enough to stay “suspended in the air for minutes to hours,” the CDC stated.
But the virus is much less transmissible outdoors and in well-ventilated spaces. That’s what Boulter, Pierce and their students are aiming for: By tracking which classrooms and other rooms on campus have the slowest and fastest air exchange rates, they hope to recommend which classrooms need air purifying units and other strategies.
“This is going to be a semester-long program, but our goal for these first two days is to make recommendations now,” said Pierce, a professor in UW-EC’s Public Health and Environmental Studies program. “Where do we put the air purifiers? Where do we suggest the professors keep the doors open? Can we open windows inside the building?”
Fall semester classes begin in a week at UW-Eau Claire, but the researchers and some students involved in other activities have already arrived on campus. The bulk of students living in the universities dormitories this semester will move in this weekend.
Hands-on research for students
The CO2 research project began with biochemistry and molecular biology students Danielle Zahn and Sydney Dame. Inspired by similar ventilation research from Harvard’s School of Public Health and other universities during the pandemic, Zahn and Dame wrote a proposal to purchase CO2 air monitors to conduct testing.
“It kind of grew from there,” Zahn said Wednesday while she monitored CO2 levels in a Schneider Hall classroom on her laptop.
Zahn and Dame presented their research at a UW-Eau Claire event, and the project took second place in the science category of a UW System competition in April called Quick Pitch.
During the spring semester, the two students began by testing a handful of rooms in the McIntyre Library on campus.
“This summer we pitched this to university administration and said, ‘We really want to roll this out across campus,’” Boulter said.
Several months later, university facilities staff identified a handful of rooms on campus with lesser-than-average ventilation, Boulter said. The group plans to test a fraction of those rooms as an audit before the fall semester begins.
“The sense is that over time, we’re going to add different classrooms,” Boulter said. “Rehearsal rooms, the weight room, where people are respiring more heavily and producing more aerosols. We’d love to extend this to different kinds of rooms over the semester.”
University administrators are working with the researchers as they conduct testing, said Michael Knuth, UW-Eau Claire associate director of marketing and communications: “Campus leaders are supportive of the great work being done by faculty, staff and students to help all Blugolds stay healthy this academic year.”
Zahn didn’t expect her work to be implemented on a larger basis.
“It was kind of a lofty dream,” she said Wednesday. “It’s definitely very cool to look back and see the work that we did … Ideally, we wanted it to get (done) here. But did I think we’d get here this soon? No. This is definitely surreal.”
The students and professors plan to continue their testing this week, focusing on rooms with a high student-per-square-foot ratio, Pierce said.
“You can see it in the students. They’re really excited,” he said. “This is hands-on environmental public health … It's just thrilling to be able to do this kind of work.”