IAQ in Schools: Protecting Students from Respiratory Illness This Winter

Every year, as the leaves change and the weather cools, school communities face a recurring challenge: the surge in respiratory illnesses that sweeps through classrooms during the fall and winter months. Influenza, RSV, COVID-19, and other respiratory infections thrive in these conditions — and schools, where students spend hours indoors in close contact, are especially vulnerable.

The stakes are high. For students, these illnesses can mean more than just a few missed days. They can exacerbate asthma, impact long-term health, and affect academic performance. For schools, they mean spikes in absenteeism, staffing shortages, and disruptions to learning that reverberate far beyond the classroom.

The good news? By improving indoor air quality (IAQ), schools can dramatically reduce these risks. The science is clear: ventilation, filtration, and infection control practices aligned with CDC, ASHRAE, and public health guidelines make classrooms healthier and safer for everyone inside.

That’s why we’re inviting you to our upcoming webinar, part of the Improving IAQ in Schools Series, where top experts will discuss how schools can leverage IAQ as a cornerstone of infection prevention this winter.

THE COST of Respiratory Illness in Schools

Respiratory illnesses are among the leading causes of missed school days in the U.S. According to the CDC, influenza alone is responsible for an estimated 22 million lost school days annually among children【1】. These absences are not only disruptive to learning but can also have long-term academic consequences. Research shows that chronic absenteeism is linked to lower test scores, reduced graduation rates, and diminished college readiness.

One study tracking medically attended acute respiratory infections (ARIs) found that in just one year, 2,295 school days were missed among 1,027 children, with influenza accounting for nearly half of both illness episodes and missed days【2】. That’s an average of more than two missed days per student per year — a burden multiplied across entire districts.

And absenteeism doesn’t only affect students. Teachers and staff are equally vulnerable, leading to classroom instability, increased costs for substitutes, and reduced instructional continuity.

WHY Indoor Air Quality Matters

While schools can’t eliminate viruses entirely, they can significantly reduce transmission risk through effective IAQ strategies. The U.S. Environmental Protection Agency (EPA) highlights that poor IAQ is directly linked to asthma exacerbations, respiratory infections, and reduced academic performance【3】.

The logic is simple: when air is cleaner, filtered, and circulated properly, fewer pathogens linger in classrooms, hallways, and shared spaces. Conversely, poorly ventilated rooms allow airborne viruses to accumulate, increasing exposure for everyone inside.

The benefits go beyond infection prevention. Improved IAQ has been shown to enhance cognitive function, attention, and test performance, giving students the best possible environment for learning.

What PUBLIC HEALTH EXPERTS Recommend

Both the CDC and ASHRAE provide clear, science-based recommendations for improving air quality in schools. Here are some of the most critical steps:

• Increase Ventilation

1. 1. • Maximize outdoor air intake by opening windows and doors when possible.
      • Ensure HVAC systems are properly inspected, maintained, and optimized to meet building needs.
      • Adjust settings to increase air exchanges per hour, especially in high-occupancy spaces like classrooms and cafeterias【4】. 

• Upgrade Filtration

1. 1. • Use MERV 13 or higher filters in HVAC systems whenever feasible.
      • Place portable HEPA air cleaners in classrooms, nurse’s offices, and other high-use areas.
      • Replace filters on a regular schedule to maintain efficiency. 

• Implement Evidence-Based Cleaning and Disinfection

1. 1. • Use products approved by the EPA for safety and effectiveness.
      • Focus cleaning on high-touch surfaces while avoiding overuse of harsh chemicals that can worsen asthma and allergies. 

• Monitor and Evaluate IAQ Performance 

1. • Utilize CO₂ monitors and IAQ sensors to track ventilation rates and identify problem areas.
   • Benchmark systems against ASHRAE Standard 241 — the most up-to-date standard for controlling infectious aerosols in buildings【5】.
   • Make adjustments as needed to ensure systems consistently meet health-based targets.

By implementing these steps, schools create healthier environments not only for infection control but also for overall student well-being.

THE IMPACT of Better IAQ

Evidence shows these measures work:

• A Lawrence Berkeley National Laboratory review found that increased ventilation rates in classrooms led to a 1.6% decrease in absences for every additional ~2 cubic feet per minute per person of ventilation【6】. 
• Schools that implemented portable HEPA filtration during the COVID-19 pandemic saw significant reductions in airborne virus concentrations, lowering exposure risks for students and staff. 
• Reducing indoor dampness and mold has been shown to decrease asthma-related health issues by 30–50%, directly improving student attendance and performance【3】.

These are not small gains — they represent healthier classrooms, reduced absences, and stronger academic outcomes across entire districts.

WHY THIS MATTERS for Education Leaders

For superintendents, facility directors, and school board members, improving IAQ is both a health imperative and a leadership opportunity. Parents want assurance that schools are doing everything possible to keep their children safe. Teachers want to know their workplaces are healthy and supportive.

By prioritizing IAQ, leaders can:

• Protect student and staff health during peak respiratory illness season.
• Reduce absenteeism, ensuring more consistent instruction.
• Enhance academic performance through healthier, more focused classrooms.
• Demonstrate leadership in aligning with national best practices and standards.

These actions don’t just protect health — they build trust, strengthen school communities, and position districts as innovators in student wellness.

Join Our UPCOMING WEBINAR

To support school leaders in this critical work, we’re hosting a free session as part of the Improving IAQ in Schools Series:

• Webinar: IAQ to Prevent Respiratory Infections
• Date: October 14, 2025
• Time: 11am PT | 2pm ET
• Register here: Click to Register

Featuring EXPERT PANELISTS:

• Erik Malmstrom, CEO, SafeTraces
• Dr. Bonnie Maldonado, Professor of Pediatric Infectious Disease & Epidemiology, Stanford School of Medicine (former CDC ACIP member)
• Lori Arzaga, Director of Environmental Services, Clark County School District

This session will provide practical, actionable strategies for preventing respiratory infections, reducing illness-related absences, and ensuring healthy environments for students and staff.

YOUR ROLE in Healthier Schools

Respiratory illness season doesn’t have to mean months of disruption. With the right IAQ strategies, districts can take control of their environments, protect student health, and keep classrooms open and thriving.

Your leadership can make the difference between schools disrupted by illness and schools where students are present, engaged, and learning.

We hope you’ll join us for this important conversation.

References

1. CDC — Burden of Influenza (2023). Link
2. Poehling, K. et al. (2018). Journal of Infectious Diseases. PMC Article
3. U.S. EPA — “How Does IAQ Impact Student Health and Academic Performance?” Link
4. CDC — “Ventilation in Buildings.” Updated 2023. Link
5. ASHRAE — “ANSI/ASHRAE Standard 241-2023.” Link
6. Mendell, M. et al. (2013). Indoor Air. PubMed. Link