HAYS COUNTY, Texas — In response to the COVID-19 pandemic, Hays CISD will have an air purifier in each room on all campuses.
“The pandemic sort of was that catalyst to really get people thinking about [indoor air quality] a little harder,” said Max Cleaver, Hays CISD's chief operations officer.
The Hays CISD School Board approved spending $4.4 million for air purifiers in September 2021. Larger rooms would require two units.
“We're just trying to think of creative solutions to keep kids in the classroom,” Cleaver said.
Hays CISD already uses 3,500 air filters and those filters are changed 10 times a year. Unlike filters, the new purifiers do not trap viruses.
Distributor WellAir’s website shows the purifier “is an airborne infection control device that inactivates aerosolized viruses, bacteria, mold spores, and pollen within the breathing zone.”
It takes about 30 minutes, Cleaver said, to purify all of the air in an average empty classroom.
“You know, layers of protection to try to stay safe,” Cleaver said.
Another method could help schools that cannot afford the purifier price tag to still be able to enhance indoor air quality.
“Typically, schools across the country are under-ventilated. That seems to be a typical problem. But I think this just kind of shows that it's because they're not being properly maintained,” said Sangeetha Kumar, an indoor air quality researcher and Ph.D. candidate for the Department of Civil, Architectural and Environmental Engineering at the University of Texas at Austin.
Kumar focuses on ventilation research and works with a team of research professors at UT.
“We are incentivized to save energy, and sometimes we do wrong stuff like cutting the ventilation rate,” said Atila Novoselac, Ph.D., a professor with the Department of Civil, Architectural and Environmental Engineering.
“We spend 90% of our time indoors. That's where you're actually getting your exposure. Certainly, outdoor qualities are important, but indoor air quality is very important looking at exposure to doses,” said Kerry Kinney, Ph.D., L.P. Gilvin Centennial Professor in Engineering.
Kumar’s Master of Science and Engineering thesis in 2019, completed under an Assistance Agreement awarded by the U.S. Environmental Protection Agency to UT, studied ventilation rates in schools.
“I would like to point out that we have to really try hard to find the problems in the schools. I mean, we are talking about ventilation. Definitely, it can always be better,” Kumar said.
She used carbon dioxide data to track ventilation levels. Her observations linked ventilation to flu absences.
“A lot of modeling about airborne infectious disease transmission, which has become a very relevant field right now, can actually use that metric [CO2] as a way to figure out how likely you're going to get infected, in the airborne sense, of things like the flu, measles, COVID,” Kumar said.
Kumar noted several limitations in the study, including the limited number of schools and uncontrollable factors, such as the way students interact outside the classroom.
She found schools could save between $1.20 to $5 per student if they increased ventilation by 20%.
While energy consumption may rise, a virus wouldn’t be able to spread as easily.
“The cost of energy was low during this time. The analysis was done for a peak flu season, which is around like, December to March. So, yeah, the minimal increase [of ventilation] could have an impact,” Kumar said.
Read Kumar's summary of the study here.
The researcher also found other pollutants decreased, ranging from formaldehyde to personal care products.
“They're looking at this balance between saving energy – which also helps save the planet and save some money – and ventilation rates in the classroom. They're always doing a balancing act,” Kinney said.
“We're talking about how most of the schools have very sophisticated air conditioning systems, including ventilation. And with some of these units, you have [the] capacity to modulate the amount of fresh air which is coming in a certain section of the school, a certain number of classrooms,” Novoselac said.
“You can't just say, ‘Oh, open the damper for total fresh air.’ You would have water dripping out of your system because it's not designed to go 100% outdoor air,” Kinney said.
Now, researchers must account for wearing masks and practicing social distance. As of Nov. 1, the trio is undergoing more indoor air quality studies, including one for UT.
“Typically on UT's campus, large auditoriums have their own mechanical systems. There is one building on campus in which an entire floor is all classrooms and they are on one mechanical system. But typically, you're going to be sharing it with your conference rooms and your offices. So, it can look differently for each of these different configurations. We're trying to understand how much does that impact it,” Kumar said.
The researchers have more than a half-dozen active projects, funded by the American Society of Heating, Refrigerating and Air-Conditioning Engineers (ASHRAE), the National Science Foundation's Integrative Graduate Education and Research Traineeship (NSF-IGRT), UT and other donors and research awards.
The responsibility to follow any indoor air quality standards falls on each person.
Do not turn to the government for help with indoor air quality. The KVUE Defenders found no enforcement of indoor air quality standards.
The Occupational Safety and Health Administration (OSHA), tasked with keeping workers safe, wrote to the Defenders: “OSHA does not have regulations for Indoor Air Quality. The agency does not routinely conduct IAQ [Indoor Air Quality] inspections of buildings within the state of Texas.”
The Texas Commission on Environmental Quality (TCEQ) and the City of Austin only monitor outdoor air.
The Texas Department State Health Services once had its own Indoor Air Quality division for government buildings, but legislators stripped it in 2015.
The only Texas agency still in charge of indoor air quality is the State Office of Risk Management (SORM). SORM advises Texas governmental agencies of best practices but does not enforce them.
“This is totally voluntary,” Cleaver said.
Tobias Elementary School in Hays CISD closed for three days during the COVID-19 delta wave.
“Will it help us with the pandemic? Yes, we believe so. But we're also looking long-range out for the next decade or 20 years,” Tim Savoy, Hays CISD's chief communication officer, said.
Savoy said the district isn’t allowed to require masks nor make rules for in-class versus at-home learning. Buying the purifiers, Savoy said, was their best option.
“We're not required to do it, but we're also not prohibited from doing it,” Savoy said.
“It’s just to give some people some peace of mind and just frankly make their air cleaner, you know?” Cleaver said.
The UT researchers said we can all take steps to improve indoor air quality at home and at work.
“By using environmentally friendly, low-toxicity cleaners,” Kinney said. “If you’re going to use a vacuum, make sure it has a HEPA filter so you don’t turn it on and spray the dust out the back.”
Novoselac said replacing carpet with tile can also improve indoor air quality because pollutants would not get trapped and then recycled into the air on the tile like they do in the carpet.
Also, using the range hood above a gas stove can reduce nitrogen dioxide levels in homes. The EPA shows nitrogen dioxide is linked to several lung conditions, including asthma and other respiratory infections.
In a peer-reviewed study, Kumar and a team with the Lawrence Berkeley National Laboratory found California’s “code-compliant range hoods may not be sufficient to maintain acceptable indoor air quality.” The team showed a range hood with an airflow rate of 200 cfm needs a capture efficiency of 70%.
“Slightly lower CEs (capture efficiencies) could be acceptable if users could be relied upon to operate the range hood for an extra 10 minutes after cooking,” the report showed.
The EPA lists more ways to improve indoor air quality, including a webpage dedicated to indoor air and COVID-19.
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