During the COVID-19 pandemic, the importance of indoor air quality (IAQ) in educational buildings gained greater awareness and significance because of its association with health, well-being, and academic performance. As indoor air quality becomes a priority for schools, colleges and universities, many are investing more in the assessment and improvement of their HVAC systems.
As the average school building is nearly a decade old, many have outdated or inadequate HVAC systems not designed for infection control or modern indoor air quality needs. COVID-19 has brought to light that a large number of schools are still operating with old HVAC infrastructures that do not meet infection control guidelines or standards.
Designed primarily for heating and cooling, these obsolete systems lack the capacity for adequate filtration of airborne pathogens, which is one key to protecting the health of students, staff and faculty. EPA Indoor Air Quality studies suggest that 40% of schools have inadequate school air filtration systems that fail to effectively reduce airborne transmission risks.
A nationwide poll conducted in 2021 among 500 higher education managers and executives showed that the most common strategy for addressing IAQ was a school HVAC filtration upgrade to reduce airborne contaminants and create healthier learning environments for students and staff.
Investing in premium school air filters can help lower disease transmission by decreasing exposure to allergens, pollutants, and airborne viruses. Additionally, these high-efficiency air filters provide economic and operational benefits for schools and universities by reducing absenteeism, lowering health-related costs, and decreasing maintenance needs. Overall, improving air filtration in schools and universities delivers long-term benefits, including healthier indoor environments, increased energy efficiency, and reduced operational expenses.
This article provides an overview of the current state of indoor air quality in educational facilities, the health and learning impacts associated with poor indoor air quality, along with the benefits and strategic approaches for investing in air filters that support healthier learning environments and long-term operational efficiency.
The State of Indoor Air in Educational Facilities
Air Quality Conditions in Classrooms
Indoor air quality in educational settings, including K-12 schools and universities, is often compromised by a variety of pollutants and structural limitations. Common issues associated with indoor air quality include:
- Elevated carbon dioxide (CO₂) levels. Overcrowded or under-ventilated classrooms can lead to excessive CO2 concentrations.
- Particulate matter. Fine airborne particles (PM1 – particles with a diameter less than 1 micron and PM2.5 – particles with a diameter less than 2.5 microns) can originate from outdoor pollution, dust or indoor activities, contributing to numerous health problems.
- Allergens. Mold spores, dust mites, and pollen are prevalent in older buildings.
- Volatile organic compounds (VOCs). Emitted from building materials, cleaning products, furnishings, and even markers, VOCs are common indoor pollutants.
Airborne particulates and VOCs are the main air pollutants found in university settings. They are generated in laboratories that use chemicals and high-traffic areas like classrooms, common areas, and dining halls.
For example, classrooms with constant foot traffic can shed up to 500,000 particles (0.3 microns or larger) per minute, while common areas and hallways generate high particle concentrations during class changes. Dining halls can produce particulates from high-density occupancy, along with gases and odors from food preparation. Laboratories where students handle chemicals generate VOCs.
University indoor air quality challenges can vary based on geographic region and seasonal conditions. Urban schools are more likely to experience higher levels of outdoor air pollution like vehicle emissions and industrial pollutants that drift into classrooms. Rural schools can have issues with dust and pesticides.
Seasonal factors also influence air quality. Cold climates may reduce ventilation during winter months, causing indoor CO2 levels to rise, while warm weather or humid regions face mold and high allergen levels. These regional and seasonal variations require tailored air quality strategies that take into consideration local environmental factors and seasonal air quality fluctuations to protect the health and well-being of students and staff.
Health Impacts
Particulate matter poses serious health risks as it can penetrate deep into the lungs and even the bloodstream, causing severe health problems. Airborne pollutants can produce various adverse effects on students, faculty and staff, including headaches, allergic reactions, eye irritation, itchy skin, bronchitis, fatigue, and discomfort that results in higher absenteeism and poor concentration.
Asthma is one of the most significant health concerns linked to poor indoor air quality. Factors such as particulate matter, mold spores, and VOCs can trigger attacks and worsen respiratory conditions. In some cases, individuals may experience sick building syndrome, where symptoms such as dizziness, nausea or irritation lessen upon leaving the building.
Health Sensitivities Among Adult Learners
As more older learners return to higher education to meet professional and career demands, there is a diverse range of age groups and health sensitivities with educational populations. Older individuals are more likely to have underlying health conditions, such as asthma and COPD, are more adversely affected by poor indoor quality. They tend to have decreased respiratory resilience and heightened sensitivity to the environment.
Chronic Absenteeism
Inadequate IAQ increases absenteeism among students and staff. Student attendance is crucial for academic success and building relationships with peers and teachers. Chronic absenteeism impacts both educational outcomes and the financial stability of the school. When students miss school due to respiratory issues, schools lose between $7 to $15 per student per day in state funding. In addition, schools can incur costs for substitute teachers, which goes against the school budget.
Poor IAQ also negatively affects academic performance. Studies indicate a direct correlation between air quality and student cognitive performance. Elevated levels of CO₂, particularly in overcrowded or poorly ventilated classrooms, can impair cognitive abilities and concentration.
Research shows that high levels of indoor air pollution and inadequate ventilation diminish performance across nine cognitive function domains, including basic activity level, task orientation, crisis response, information seeking, information usage, and strategic thinking. All are important for learning and conducting complex tasks.
Why Schools and Universities Are Vulnerable
Higher education settings such as classrooms, lecture halls, dining areas and libraries, where large numbers of students and staff gather, increase the risk of airborne transmission of respiratory viruses. High occupancy density creates unique challenges for maintaining effective ventilation and indoor air quality, as it escalates the demand on ventilation systems. An increase in the number of occupants raises CO₂ levels and introduces more airborne particles and pathogens that can potentially overwhelm standard ventilation systems and compromise air quality.
In addition, high foot traffic and constant movement can disturb settled dust particles, raising levels of particulate matter (PM) in the air. A building’s location, design, and activities also influence PM concentration. Buildings situated near roads and industrial zones are more likely to experience higher infiltration of outdoor PM due to pollutants. Activities such as cooking, printing, and laboratory work can generate indoor particulates within classrooms. In addition, poorly sealed buildings and those with inadequate filtration systems can allow more outdoor pollutants to enter indoor areas.
Outdated HVAC systems
A national survey by the National Center for Education Statistics on public schools found that the average age of the main school building in U.S. public schools is 49 years, with 38% constructed before 1970. Additionally, one-third of public schools have never undergone major renovations. Similarly, over 50% of American college campuses were built between 1951 and 1990. This indicates that much of the nation’s education infrastructure is aging.
Older buildings often lack the modern filtration and ventilation capacity needed to maintain clean, healthy indoor air across campus environments. As campuses grow and change, the limitations of outdated systems struggle to meet today’s air quality and performance standards. Many schools and universities in the U.S. do not meet the minimum ventilation design standard outlined by the American Society of Heating, Refrigerating and Air Conditioning Engineers (ASHRAE).
To comply with modern standards and improve air quality, HVAC systems in many educational institutions require renewal or replacement. A 2020 Government Accountability Office report found that 41% of school districts need to update or replace HVAC systems in at least half of their schools. This represents about 36,000 schools nationwide that need updates.
Budget Constraints
While schools and universities realize the importance of HVAC improvements, budget restraints often cause delays. The 2021 State of Our Schools report revealed a staggering $85 billion funding gap needed to properly maintain school buildings and equipment nationwide.
Despite flat budgets and rising operating costs, schools and universities should actively pursue alternative funding sources to modernize HVAC systems. Delaying these upgrades poses serious risks to health, learning outcomes, and overall building safety.
Investments in modernizing HVAC systems with premium air filtration will not only improve indoor environments but also positively affect learning environments, boost student and staff productivity, lower maintenance costs and reduce energy costs.
What Are Premium Air Filters?
While HVAC systems bring fresh air indoors through ventilation, this process does not eliminate airborne pathogens. While ventilation helps dilute contaminants, air filtration removes particles such as dust and aerosols from the air before it circulates in indoor spaces. While only a single component, air filters impact almost every performance feature of the HVAC system.
MERV and HEPA
Air filters are evaluated based on how effectively they capture small airborne particles, using the Minimum Efficiency Reporting Value (MERV) rating system. For optimal performance, schools and universities should implement air filters with MERV ratings between 13 and 16, specifically those marked with a MERV-A designation. This MERV-A label signifies that the filter will sustain its efficiency throughout its operational lifespan. Air filters rated a minimum of MERV 13/13A capture an average of 85% of particles 1 micron and larger when properly installed in HVAC systems. High-Efficiency Particulate Air (HEPA) filters are even more effective, capable of removing at least 99.97% of particles as tiny as 0.3 microns.
Carbon Filtration
Molecular filters with activated carbon are effective in removing gases and odors from the air through a process called adsorption. In this process, gas-phase molecules adhere to the surface of the activated carbon, which has an extremely high surface area due to its porous structure.
These filters are highly effective for controlling odors and chemical contaminants in:
- Science laboratories: remove chemical fumes and VOCs.
- Cafeterias: control food odors and cooking by-products.
- Art rooms or industrial classrooms that utilize glues, paints or solvents.
Prefilters and Final Filters
In HVAC systems, prefilters and final filters work together in a multi-stage filtration process to effectively clean environments with different pollutants. Using a combination of different filters targets specific contaminants such as allergens, mold, and odors.
Prefilters are often one, two, or four-inch pleated panel filters and serve as the first line of defense by removing large airborne particles such as dust, pollen, and lint. They are installed upstream of other filters in the air handling unit. For example, in a school setting, a MERV-8A or 9A prefilter removes larger particles before they accumulate on the heating or cooling coils, which reduces heat transfer effectiveness or before they build up on the final filter, reducing airflow into classrooms.
Final filters are installed downstream from the prefilter and before air enters the ductwork and is delivered into the building space. These filters typically have a MERV rating of 13-16 and are designed to remove smaller airborne contaminants. They ensure that the HVAC system delivers cleaner, safer air into the classrooms and can be considered as the last line of defense.
Integrated Systems vs. Standalone Units
Integrated filters are built directly into existing HVAC systems and can be upgraded from standard to premium filters, depending on system compatibility. Most commercial HVAC systems have the framing support to accommodate filters with MERV ratings of 8- 16. However, standard HVAC systems in schools typically cannot accommodate HEPA filters due to fan design limitations and pressure drop issues. Installing HEPA filters often requires significant modifications or specialized air handling units to maintain airflow and ventilation rates.
In such cases, standalone units, also known as air purifiers or air cleaners, are ideal. When equipped with HEPA filters and activated media filters, these portable units effectively reduce particulate matter and gaseous pollutants. They can be smaller plug-and-play units that require minimal installation and maintenance, or they can be larger ceiling mounted units for athletic spaces such as gyms, locker rooms, and indoor swimming pools or larger spaces such as auditoriums. Air purifiers and cleaners can be powerful filtration devices that deliver performance beyond the capabilities of most existing school HVAC systems.
Camfil’s Premium Air Filters and Air Cleaners Routinely Used in Schools and Universities
- 30/30 Dual 9 or Farr 30/30 panel filters for prefiltration in multi-stage units.
- AQ13 panel filters for single-stage units configured to hold air filters no greater than 4 inches in depth and supplying air to human-occupied, but non-critical spaces such as offices.
- Durafil ES3 V-bank style air filters for final filters in multi-stage units supplying air to human-occupied or production areas not requiring HEPA filtration.
- CityCarb I V-bank style particulate and molecular air filter that combines MERV 14A particle removal efficiency and ozone removal efficiency of 90%.
- Absolute VG V-bank style filters for areas where up to 99.99% @ 0.3 micron HEPA filtration is required and the air handling unit is configured for box-style HEPA filters.
- CamCleaner CC500 portable air purifier with HEPA filtration.
- CamCleaner CC X-Series industrial air cleaner with modular construction capable of both particulate and molecular filtration in large spaces.
Improved Indoor Air Quality – Health and Cognitive Benefits
IAQ plays a vital role in promoting student health, cognitive development, and academic performance. By prioritizing clean air, schools and universities can create healthier, more effective learning environments.
Health Benefits for Educational Communities
Recent studies have shown that upgrading HVAC systems and integrating HEPA cleaners in classrooms provides health advantages. Reduced transmission of airborne pathogens minimizes the spread of colds and flus while lowering the incidence of asthma and allergy flare-ups. Improved IAQ also supports better respiratory health and strengthens the immune system.
Academic Performance Enhancement
The COGfx study, a multi-phase research initiative led by Harvard University, Syracuse University and SUNY Upstate Medical University, found that improved IAQ led to a 101% increase in cognitive test results.
Key academic benefits of well-ventilated classrooms include:
- Improved concentration, memory and cognitive performance.
- Reduced absenteeism and disruption.
- A more comfortable environment aligned with academic achievement.
Staff Well-Being and Performance
Classroom air quality improvement also supports the health, performance, and satisfaction of teachers and school staff. Cleaner air reduces sick leave, ensuring consistent instruction in educational programs.
Healthier, more comfortable working conditions enhance productivity, boosts morale and job satisfaction. When educators feel healthier and more engaged, overall quality instruction and school culture improve, leading to higher job satisfaction and better job retention.
Energy Efficiency and HVAC Performance in Educational Facilities
Energy Efficiency Gains
HVAC systems represent the majority of energy consumption in schools and universities. Upgrading to premium, high-efficiency filters will have a big impact on system performance and energy efficiency, resulting in major savings on utility costs.
Optimized System Load for Educational Buildings
High-efficiency filters enhance the performance of HVAC systems by decreasing airflow resistance and minimizing pressure drop. As a result, less energy is needed to maintain consistent indoor temperatures and air quality in classrooms, lecture halls and other campus areas, especially during high-demand periods.
These advanced filters are also more effective in capturing airborne contaminants, reducing the load on HVAC systems. This not only reduces cooling energy requirements but also contributes to cleaner indoor air. By maintaining consistent airflow, minimizing pressure fluctuations, and reducing strain on critical components, these filters help extend the lifespan of HVAC systems.
Energy Cost Savings for Educational Budgets
Effective filter management lowers cooling and heating costs by keeping systems clean, efficient and free from dirt and debris. Clean filters allow air to flow more efficiently, reducing strain on equipment and improving energy efficiency. By maintaining optimal system performance throughout the year, schools can reduce heating costs in the winter and cooling costs in the summer.
Schools that upgrade to efficient air filters can cut HVAC-related energy consumption by up to 80%, lowering utility costs. For example, by switching to premium filters, Montgomery County Schools in Pennsylvania captured up to 85% more airborne particles. This resulted in healthier learning environments and achieved a 15- 18% energy savings, which translates to hundreds of thousands in annual savings.
Utility savings such as these allow more funding to be allocated to other educational programs and maintenance rather than utility bills.
Sustainability Benefits for Educational Institutions
By adopting premium HVAC filters, educational institutions can reduce their carbon footprint. These advanced filters enable HVAC units to operate with lower energy demands, helping to reduce greenhouse gas emissions associated with heating, cooling, and water purification processes across campus.
This results in a cleaner, greener campus that aligns with the values of environmentally-conscious educational institutions. It also demonstrates corporate social responsibility to stakeholders.
Additionally, installing premium filtration systems can contribute directly to Leadership in Energy and Environmental Design (LEED) certification by earning points in categories such as indoor environmental quality.
Maintenance Cost Savings – Labor and Materials
By reducing airborne dust and particulate matter, premium filters help to prevent buildup in HVAC systems and prolongs the lifespan of HVAC components. This leads to fewer repairs and replacements, which reduces maintenance costs, minimizes system downtime, and lowers labor needs.
High-quality air filters also often require less frequent replacement. When used in combination with a prefilter, final filters can last 6 to 12 months longer than standard filters due to their high-quality materials and enhanced design for airflow efficiency. This extends service intervals and reduces operational costs. Fewer filter changeouts mean less disruption to classroom activities and campus operations.
Labor Hours and Staffing Optimization
By extending filter life, premium filtration systems reduce the frequency of replacements, reducing the time technicians spend on routine maintenance. This not only cuts labor costs but frees technicians to spend time on more urgent, complex maintenance issues, improving overall facility performance.
Consistent filtration performance can improve staff productivity by focusing on educational support activities. It also reduces unplanned repair costs and reduces emergency maintenance calls during critical educational periods.
Procurement and Inventory Efficiency for Educational Institutions
Standardizing high-efficiency filters across campus allows educational institutions and school districts to negotiate volume-based pricing for bulk purchases. The longer lifespans of premium filters simplify inventory management by reducing the number of SKUs and change cycles. And with fewer filter types and less frequent replacement, facility maintenance areas require less physical storage space for HVAC filter inventory. Standardized purchasing and reduced frequency of changeouts streamlines the procurement process with fewer requisitions, less manual oversight and more precise budgeting.
Disposal Cost Savings and Environmental Benefits
Fewer filter replacements generate less waste, resulting in reduced filter disposal frequency. This, in turn, means fewer dumpster pickups, reduced landfill fees, and lower hauling and labor charges.
The decreased volume of non-biodegradable materials sent to landfills supports sustainability initiatives, carbon reduction targets and compliance with green building standards such as LEED or Energy Star.
Waste reduction efforts also provide real-world opportunities for environmental education. By using filter optimization projects, educational institutions can demonstrate environmental responsibility and engage students in sustainability discussions using campus-based case stories.
Cost-Benefit Analysis for Educational Investment
While premium filters have a higher upfront cost compared to standard filters, they offer significant long-term financial and operational advantages. Standard filters, with their low initial cost, quickly become clogged, resulting in dramatically higher energy consumption as well as increased labor and disposal costs due to their short service life. The costs of premium filters are offset by extended service life, improved HVAC efficiency and reduced inventory and maintenance.
Instead of simply evaluating filters based on price, examining the total cost of ownership (TCO) can provide a clearer picture of their overall value. This evaluation should include operational costs, energy consumption, operational gains, labor and disposal costs. Software such as Camfil’s LCC Green Software can be used to calculate the TCO of different filters under various conditions using real-life data.
Budget Reallocation Opportunities
Investing in premium air filters creates opportunities for budget reallocation within educational institutions. The overall savings gained from improved energy efficiency and reduced maintenance costs can be redirected to support different institutional priorities, such as:
- Academic program improvements, such as curriculum development and staff training.
- Facility upgrades that modernize infrastructure and help attract and retain students.
- Technology improvements that further reduce energy and maintenance costs while equipping learning environments with the latest digital tools.
Implementation Considerations for Educational Facilities
Upgrading to premium air filters requires a strategic, multi-step approach. This process should include a comprehensive assessment, proper filter selection, staff training and ongoing performance monitoring.
Assessment and Planning for Educational Environments
The first step in improving IAQ at schools is assessing their needs. It involves:
- Conducting an IAQ audit to evaluate pollutant sources, ventilation effectiveness and particulate levels to determine filtration requirements.
- Performing an occupancy-based analysis to outline occupancy patterns and usage throughout different buildings.
- Evaluating the current ventilation systems and poor circulation areas.
It is also important to establish baseline performance metrics to enable ongoing performance tracking, ROI calculations and alignment with sustainability reporting.
Air Filter Selection for Educational Applications
Choosing the right filter requires a thorough evaluation of system compatibility, facility needs, and infrastructure diversity.
Key considerations include:
- Conducting a compatibility check of the HVAC system to determine whether it can support premium filters without compromising performance.
- Assessing filtration performance based on the educational environments, such as minimizing airborne contaminants, controlling allergens and ensuring consistent IAQ in high-occupancy spaces.
- Considering the age and capacity of HVAC systems in older buildings, which may have limited airflow. Upgrades or system modifications may be required to accommodate high-efficiency filters.
- Selecting the filter solutions that adapt to the varying designs of different buildings, which can affect airflow requirements.
- Consider adding individual room air purifiers or industrial air cleaners for larger spaces where needed.
Training and Staff Buy-In for Educational Teams
The successful implementation of premium air filters depends on staff engagement, training and change management. The facilities and maintenance team should be educated on new filtration methods and goals through targeted training sessions. This should focus on filter specifications and proper installation, monitoring air quality improvements, and troubleshooting pressure drops or airflow issues.
Standard operating procedures should define inspection and replacement schedules for maintenance teams. Additionally, communication strategies should be developed to inform staff and stakeholders on the purpose and benefits of premium filter upgrades, addressing any potential resistance from faculty and administrative leadership.
Monitoring Results and Performance Validation
Ongoing assessments enable schools to adapt their air quality management strategies in real time, ensuring the health and safety of students and staff. By utilizing advanced sensors and monitoring systems, schools can collect data on key pollutants including VOCs, particulate matter and CO₂ levels.
Analyzing this data allows for early detection of emerging issues, identification of trends, and timely adjustments to ventilation systems or filtration efficiency. These proactive measures not only protect health but also enhance the learning environment by reducing distractions and discomfort caused by poor educational building air quality.
Clean indoor air is critical to the health, academic performance and productivity of staff and students in schools and universities. With approximately 51 million people occupying school buildings on any given day, IAQ must be a top priority in the mission of educational facilities. School air filtration benefits not only include improved air quality, but lower energy consumption, reduced maintenance and inventory costs, and enhanced comfort and safety.
For many older educational facilities that cannot accommodate major HVAC designs, premium air filters offer a practical, high-impact solution. They represent a smart, future-ready investment in creating healthier learning environments and promoting educational excellence.
Camfil offers clean air solutions tailored to address air quality issues in educational institutions. To learn more about our premium air filtration capabilities for schools and universities, visit Camfil’s schools and universities clean air information page or connect with a Camfil expert who can provide product knowledge and support in upgrading the filtration capacity of your HVAC system.
¹ https://www.epa.gov/iaq-schools/reference-guide-indoor-air-quality-schools
² https://www.fmlink.com/survey-colleges-issues-effective-iaq-solutions/
³ https://www.epa.gov/pm-pollution/particulate-matter-pm-basics
⁴ https://blog.csba.org/national-survey-school-facilities/
⁶ https://pmc.ncbi.nlm.nih.gov/articles/PMC8789458/
⁷ https://www.gao.gov/products/gao-20-494
⁸ https://www.incidentiq.com/blog/2024-2025-k12-facilities-management-survey
¹⁰ https://healthybuildings.hsph.harvard.edu/research/indoor-air-quality/cogfx/
¹¹ https://airsysnorthamerica.com/a-school-hvac-upgrade-is-it-really-necessary/
¹² https://centralplumbinghvac.com/why-montgomery-county-schools-are-switching-hvac-filter/
