After the pandemic hit, the largest school district in Kansas set to calculating how much outdoor air it should pull into its buildings.
Wichita Public Schools turned to the nation’s top sources for expertise, then boosted ventilation and filtration in ways that scientists say dramatically cut the risk of inhaling COVID-19.
Evidence that schools — as well as operators of other buildings that bring people together — should take those steps has solidified, buoyed by scientific findings that the virus spreads primarily through particles in the air, not by lurking on doorknobs and table tops.
Yet scientists say most American schools probably don’t bring in enough outdoor air or filter indoor air the way they should. In some schools, the windows don’t even open.
“We are under-ventilating nearly every space we spend time in indoors,” Harvard School of Public Health professor Joseph Allen said in a recent media briefing.
A year into the pandemic, some Kansas schools don’t know one of the most vital facts about their air quality: The rate at which air turns over.
In the course of a single hour, say experts at Harvard, the air in a typical classroom should effectively change out four to six times, replaced with outdoor air and appropriately recycled indoor air.
Harvard offers a five-step guide to help schools measure classroom ventilation and a list of questions that communities should ask their school leaders. Though the problem hardly starts and stops there.
Poor air quality takes a subtle daily toll on health, psychological well-being and ability to work and learn effectively, scientists warn. So though fending off COVID-19 is top of mind today, communities should push for proper ventilation and filtration in their buildings even after the pandemic is in the rearview mirror.
No regulation, little information in Kansas
No one tracks ventilation in Kansas schools, let alone whether the buildings make changes to hit targets set by engineers and public health experts for pandemic safety.
Though federal agencies say schools should take air quality seriously, infectious disease experts and engineers say the government did too little, too late to explain the urgency and the options.
In the vacuum of information, schools in Kansas and elsewhere spent money a dazzling array of products (such as ionizers) that many experts recommend avoiding.
State agencies, meanwhile, don’t employ staff with the right expertise to help districts measure their ventilation and plot a course to improvement.
The Kansas State Board of Education adopted guidelines explaining the value of ventilation and pointing schools to filters recommended by the American Society of Heating, Refrigerating and Air-Conditioning Engineers.
It doesn’t, however, require schools to act.
Not all school buildings are created equal
The layout of the ducts running through Wichita schools lets the district draw in more air when it needs to.
For that, facilities director Luke Newman is grateful.
“Fresh, outside air is always going to give you a healthier space,” he said. “Whether you’re fighting COVID or just in normal circumstances.”
But many schools across the country lack heating and cooling systems that allow for adequate changes to ventilation without shelling out millions of dollars. They don’t necessarily have windows that open, either.
Some schools can supplement their ventilation with high-quality filters, such as the MERV-13s that Wichita schools installed in some high-risk areas. But many heating and cooling systems simply can’t handle those. Portable machines with HEPA filters offer another option, but don’t work in large spaces, for example.
Other options for buildings that can’t easily boost filtration and ventilation include tweaking humidity levels or attacking the virus with ultraviolet irradiation.
Getting a ‘baseline’ picture of air-change rates
Before choosing an approach, though, schools need to do their homework: piece together a picture of their air-change rates.
Measuring airflow in every single classroom goes beyond what most districts can take on. In Wichita, for example, the district says it would simply cost too much. It uses building-wide averages, which it says greatly exceed Harvard’s recommendations.
Marcel Harmon is a building scientist in Lawrence and a former school board member there who hit the phones when the pandemic struck, urging state and local agencies to help spread reliable information about air quality.
He recommends that schools spot-check their air-change rates in typical classrooms and other spaces around their buildings.
“At least we’d have a starting point,” he said. “We don’t even have a baseline.”
Then comes the next hurdle, exploring solutions.
“And sometimes it’s just really frustrating,” said Harmon, whose building consulting firm has worked with schools in other states. “They know they need to do something, but they don’t have it in the budget.”
Richard Corsi, dean of engineering at Portland State University, estimates a portable machine with the right kind of filter costs about $10 a year per student in a typical classroom of 20 to 25 kids.
But after a year in which many children attended school remotely and fell behind academically, Kansas urgently wants to catch them up. That means targeting money at summer or after-school programs, extra counseling or even lengthening the school year.
State education officials support improving air quality, but offer districts this advice:
“Don’t spend your first dollar upgrading your HVAC,” head of school finance Craig Neuenswander recommends. “Let’s look at some of the needs that your students are going to have coming out of the pandemic, and address those first.”
Celia Llopis-Jepsen reports on consumer health for the Kansas News Service.