Classrooms aren’t just rows of desks and whiteboards—they’re living, breathing environments. And the air inside them plays a bigger role in health, comfort, and learning than many people realize.
Studies show that indoor air quality (IAQ) in schools directly affects how well students concentrate, how often they and their teachers get sick, and even how they perform on tests. The good news? With the right approach to ventilation and filtration, schools can create healthier spaces that help students, teachers, and staff all do their best work.
Why Indoor Air Quality Matters for Everyone in Schools
Children breathe more air for their body size than adults, and they spend much of their day inside school buildings. But students aren’t the only ones affected—teachers and staff share the same air, often for even longer hours each day. Poor IAQ can contribute to fatigue, headaches, respiratory issues, and absenteeism for everyone in the building.
The U.S. Environmental Protection Agency (EPA) reports that indoor pollutant levels in schools can be 2 to 5 times higher—and sometimes even 100 times higher—than outdoor air, impacting 55 million students and 4 million teachers in the U.S. (EPA).
Even more concerning, nearly half of U.S. school districts lack a formal indoor air quality management program (EPA). Without one, harmful pollutants like PM₂.₅, ozone, and volatile organic compounds (VOCs) can quietly undermine the health and performance of students, faculty, and staff every single day.
Better Ventilation, Better Learning and Teaching
Ventilation is one of the most important tools for improving school air quality. Bringing in enough fresh air dilutes pollutants and keeps CO₂ levels in check—helping students stay alert and enabling teachers to maintain focus and energy throughout the day—but because much of the air indoors is recirculated, effective air filtration is equally critical to remove particles and contaminants that ventilation alone can’t address.
Research shows that schools with higher ventilation rates see 2–3% gains in math and reading pass rates (EPA Evidence Summary). For teachers and staff, better IAQ can mean fewer sick days, more consistent energy levels, and improved voice health—an important factor for those who spend hours speaking in front of classes.
A UK study found that 80% of indoor classroom air pollution comes from outdoors, and just 6% of high-pollution days account for 17% of annual exposure (The Guardian). This shows why schools need both good ventilation and effective air filtration systems to protect everyone inside.
Asthma, Allergies, and Absenteeism
Poor indoor air quality doesn’t just make classrooms uncomfortable—it can make people sick. For students, exposure to dampness or mold can increase asthma risk by 30–50% (School Infrastructure). For teachers and staff, the same issues can trigger allergies, respiratory infections, and chronic cough, which in turn can lead to lost instructional time and reduced productivity.
Even small increases in pollution matter. For every 1 µg/m³ increase in PM₂.₅, absenteeism rises by 4%, and for every 1 ppb increase in ozone, absenteeism rises by 1%. Cutting pollution in half could save a single district around $452,000 per year in lost attendance funding (arXiv).
Comfort Counts for Students and Staff
It’s not just about what’s in the air—it’s also about how the classroom feels. Temperature, humidity, and air movement all affect concentration and energy. Studies suggest that keeping classrooms between 68–72°F (20–22°C) creates the best environment for learning and teaching. Pair that with good airflow, and both students and staff can focus longer and feel better throughout the day.
Filtration: A Quiet Game-Changer
Ventilation brings in fresh air, but air filtration for schools removes many of the harmful particles already indoors. Upgrading to MERV 13 air filters or higher can trap fine particles like bacteria, mold spores, and even some viruses—protecting the respiratory health of students, teachers, and support staff.
A 2024 study found that HEPA filters in classrooms can reduce particulate matter by 40–60% and airborne viral RNA by 30–50%, with only a 1–2% increase in energy costs (arXiv). This means schools can improve IAQ and energy efficiency at the same time.
The Payoff for the Whole School Community
Poor IAQ in schools costs the U.S. between $36 and $92 billion annually in lost productivity and health-related expenses (EPA).
On the flip side, well-maintained schools—those without major maintenance backlogs—see:
For staff, better IAQ means fewer sick days, improved job satisfaction, and a safer, more comfortable working environment.
Action Steps for Cleaner, Healthier Air in Schools
Here are some practical, research-backed ways schools can improve air quality for everyone inside:
Creating healthier learning environments starts with the air we breathe. American Air Filter partners with schools and organizations to design filtration strategies that not only improve indoor air quality but also help increase energy efficiency. Speak with an AAF representative to find the right approach for your facility.
