K-12 Schools: The Most Important Lessons May Be About Indoor Air Quality

Indoor Air Quality (IAQ) research has been developing quickly as we learn more about SARS-CoV-2, the virus that causes COVID-19, and the increasingly accepted fact that it’s spread through the air. With IAQ guidance evolving in response to new findings, we thought it would be helpful to highlight articles and research that reflect the latest recommendations and offer clear advice.

K-12 school buildings have been an area of heightened concern, as students, parents, teachers, and school districts work to find strategies to keep kids and staff safe at school. All of these stakeholders are invested in getting students back to the school environment, as there is an increasing awareness that students are missing out both academically and socially by being unable to share space with one another. And teachers’ unions have been demanding that the return to onsite learning happens only when they are satisfied that their health and safety has been adequately taken into account. The stakes could not be higher, as the economy depends on parents’ ability to work effectively, which has in many cases been compromised by the need to supervise the education of young children.

Solutions to these massive societal challenges rest on us, the engineers designing approaches to protecting indoor air in schools and the suppliers helping them do it. Complicating the situation further is the fact that school budgets are perpetually tight, and facility maintenance is often deferred in favor of technology or security updates, according to The ACHR News, which reports:

“The federal General Accounting Office (GAO) recently found that 41 percent of school districts across the country need to update or replace HVAC systems in at least half of their schools, representing about 36,000 schools nationwide that need HVAC updates.”

As we know, updating an HVAC system comes at a high cost and often takes quite some time, particularly given that in the current case MERV 13 filters and 4-6 air changes per hour are recommended at a minimum to mitigate aerosols carrying SARS-CoV-2. What are schools to do? The Wall Street Journal recently noted that:

“Health scientists and mechanical engineers have started issuing recommendations to schools and businesses that wish to reopen for how often indoor air needs to be replaced, as well as guidelines for the fans, filters and other equipment needed to meet the goals.”

Fortunately, WSJ also offers some lower-cost approaches to ensuring adequate air changes and safety, including opening windows and doors, installing window fans, and installing in-room filters. Certainly the lowest-cost option is opening windows and doors and leaving it at that, but we’re learning that in the absence of wind or some other natural force, mechanical approaches are necessary. This is why fans can help, but WSJ also notes the danger that they can pose, cautioning schools to “avoid positioning that would blow air directly from one person to another”.

Portable HEPA filters are another option cited, but they must be appropriately sized for the room and safe to operate, which in many cases eliminates residential-type air purifiers both because they don’t filter a sufficient volume to deliver the required number of air changes and because they require long extension cords strung across the floor… extension cords that can be easily unplugged to charge a device. In addition, in a learning environment, the noise from these appliances can distract students and prevent them from hearing their teachers and one another without raising their voices (which poses a higher risk of spreading the virus, according to MIT), which could lead to them being unplugged, moved to a corner of the room limiting effectiveness, or removed from the space altogether.

We strongly believe in the need to employ safe, effective, and affordable solutions to get kids, teachers, and staff back to school and parents back to work. Educating school administrators and towns on the latest research and best practices is an important step to making this happen, which is where we and our partners come in. It’s in all of our best interest to help them discover the best solutions possible given their buildings and budgets, whether those are new top-of-the-line HVAC systems, in-room air purifiers, or properly using a combination of approaches to achieve the safest result.