Four Ways To Improve Indoor Air Quality In K-12 Schools

Upgrades and modifications to enhance IAQ are critical, and funding from COVID-19 relief bills can help school facilities teams make them happen.
Upgrades and modifications to enhance IAQ are critical, and funding from COVID-19 relief bills can help school facilities teams make them happen.

Four Ways To Improve Indoor Air Quality In K-12 Schools

Upgrades and modifications to enhance IAQ are critical, and funding from COVID-19 relief bills can help facilities teams make them happen.

Four Ways To Improve Indoor Air Quality In K-12 Schools

By Danny White

One thousand hours. That’s how much time most American children spend at schoolevery year — when there isn’t a pandemic, that is. COVID-19 closed school buildings for much of 2020 and parts of 2021 to keep kids — as well as educators, administrators, and school facility employees — out of confined indoor spaces where the virus could spread through the air or via close contact.

While COVID-19 shined a light on indoor air quality (IAQ) in schools, it should have been a priority long before the pandemic. Poor IAQ can lead to health problems such as fatigue and headaches; cause or worsen asthma and other respiratory illnesses; and even affect students’ ability to learn. Recent academic research found3 “compelling evidence…of an association of increased student performance with increased ventilation rates,” yet “ventilation rates in classrooms often fall far short of the minimum ventilation rates specified in standards.” An estimated 41% of U.S. school districtsneed to update or replace heating, ventilation and air conditioning (HVAC) systems in at least half of their schools, amounting to about 36,000 schools across the country.

IAQ K-12 School
(Credit: Getty Images/Drazen Zigic)

Improving IAQ in schools should be treated as a priority. It starts with upgrading, modifying or retrofitting critical building systems or features, such as HVAC systems. School facilities teams, therefore, have an important role to play in creating healthier indoor spaces with building improvements that support better IAQ.

But any talk of building improvements raises two questions: How can schools pay for these projects and where do they begin?

Funding IAQ Upgrades

While school budgets are always top of mind, it’s also important to realize poor IAQ can end up costing schools morein the long run by accelerating deterioration and reducing the efficiency of their physical plant and equipment, leading to expensive repairs. HVAC systems are also among the largest energy users in schools6, and system improvements could cut the $6 billion that public schools spend on energy annually by up to 25% — a potential savings of $1.5 billion7.

Total costs for improvements will vary, but are unlikely to drain a school’s budget, even if multiple HVAC systems need to be replaced. Academic research found the net annual costs of increasing ventilation rates8 in U.S. public schools is “less than 0.1% of typical public spending on elementary and secondary education in the United States.” In schools with relatively modern infrastructure, Honeywell estimates that the cost of improving IAQ is just $11 to $15 per student.

In addition, schools have an opportunity right now to partially, or even fully, pay for building upgrades by capitalizing on available government funding. In 2020 and 2021, Congress passed three stimulus bills that provided close to $190.5 billion9 to the Elementary and Secondary Emergency Education Relief (ESSER) Fund. The ESSER fact sheet specifies10 that this funding can be used to improve the indoor air quality in K-12 school facilities, as well as repair and improve school facilities to reduce risk of virus transmission and exposure to environmental health hazards.

The funding from the three bills is available to State Education Agencies (SEAs) through September 2023. The application process varies by state, but usually requires a LEA (Local Education Agency) to submit a budget for approval to their SEA. The last chance to receive any funding from the first bill is approaching in September 2021, which means the time to apply is now.

As facility teams work together with school administrators, LEAs and SEAs to recommend the best improvements for their individual buildings, they should take into consideration four best practices that support better IAQ.

1. Improve Ventilation

Effective ventilation requires both bringing in oxygenated air from outdoors and removing stale indoor air. To adjust ventilation within school buildings:

  • Avoid shutting down HVAC systems. Purge building air by extending the operating times of HVAC systems to run before the earliest staff arrive for the day and after the last occupants have left for the night.
  • When possible, increase the number of air exchanges per hour to provide fresh air to closed spaces. This can be achieved through natural or mechanical ventilation.
  • Fresh air intake should also be increased to 100% or the maximum amount possible.

Recent research from the Centers for Disease Control and Prevention found the incidence of COVID-19 was 39% lower in schools that improved ventilation11 by opening windows, opening doors or using fans, or those tactics in combination with air filtration methods.

2. Filter and Clean the Air

Air filtration and cleaning technologies capture contaminants that can linger in the air. Electronic air cleaners (EACs) — which use an electric charge to help remove solid and liquid impurities from the air without impeding air flow — with UV systems can be installed inside a commercial HVAC system as a retrofit without causing a pressure drop, so facility managers do not need to remove old equipment and install a new system entirely.

Additionally, new research shows mobile HEPA air purifiers can help reduce airborne contaminants12 by capturing 97% of particles as small as 0.3 microns and even smaller. Placing these purifiers in a school’s most highly trafficked areas would be especially effective for reducing contaminants.

3. Measure IAQ with Sensors

Pollutants, temperature, and relative humidity of indoor air also affect students. Researchers found higher air temperatures resulted in lower grades13 on tests that evaluated students’ reading and math skills. High humidity can promote bacteria and mold growth14 as well as conditions for dust mites, which exacerbate respiratory conditions and allergies, while low humidity can cause dry, itchy skin and upper respiratory irritations. Relative humidity is an important factor in maintaining optimal air quality and comfort, and IAQ sensors can provide a real-time understanding of this as occupancy increases.

IAQ sensors that determine a building’s environmental state and air quality status offer an effective, automated solution to monitor the presence of a range of pollutants as well as humidity and temperature. Integrating these sensors into an HVAC system allows the system to detect contaminants and then automatically clean the air and adjust ventilation as needed.

4. Pair Building Management with Analytics

Centralized monitoring and control via dashboards make management of a school simpler and more user friendly while supporting IAQ. Analytics systems can be integrated into a Building Management System (BMS), allowing teams to monitor humidity, ventilation, temperature, pressure and pollutant levels through real-time data on dashboards. Facility managers can run reports to analyze historical data and spot trends.

A BMS also can be used to maximize energy efficiency by load-balancing heating or air conditioning based on occupancy levels of certain rooms or spaces (e.g., a sports facility that is only used certain days of the week or times of day), which can lower overall energy costs.

Better IAQ Means Healthier Schools

While there isn’t one single solution for better-quality IAQ, a number of technologies are available, and the newly available federal funding makes them accessible for schools, no matter the budget. U.S. schools should treat this point in time as an opportunity to improve the quality of the air that students and school employees breathe every day and build healthier environments that enhance the academic experience.


1 Ed 100, School Hours: Is There Enough Time to Learn?, January 2020 [Accessed June 11, 2021]
2 U.S. Environmental Protection Agency, Care for Your Air: A Guide to Indoor Air Quality., August 28, 2019 [Accessed June 11, 2021]
3 Wiley Online Library, The ventilation problem in schools: literature review., W.J. Fisk, July 6, 2017 [Accessed June 11, 2021]
4 U.S. Government Accountability Office, K-12 Education: School Districts Frequently Identified Multiple Building Systems Needing Updates or Replacement., Jacqueline M. Nowicki, June 4, 2020 [Accessed June 11, 2021]
5 U.S. Environmental Protection Agency, Take Action to Improve Indoor Air Quality in Schools., March 1, 2021 [Accessed June 11, 2021]
6 U.S. Environmental Protection Agency, Heating, Ventilation and Air-Conditioning Systems, Part of Indoor Air Quality Design Tools for Schools., October 26, 2020 [Accessed June 11, 2021]
7 Learning Policy Institute, The Air We Breathe: Why Good HVAC Systems Are an Essential Resource for Our Students and School Staff., Michael Griffith and Allie Pearce, December 8, 2020 [Accessed June 11, 2021]
8 Wiley Online Library, The ventilation problem in schools: literature review., W.J. Fisk, July 6, 2017 [Accessed June 11, 2021]
9 National Conference of State Legislatures, Elementary and Secondary School Emergency Relief Fund Tracker., June 1, 2021 [Accessed June 11, 2021]
10 Office of Elementary and Secondary Education, U.S. Department of Education Fact Sheet: American Rescue Plan Act of 2021 Elementary and Secondary School Emergency Relief Fund., March 2021 [Accessed June 11, 2021]
11 Morbidity and Mortality Weekly Report (MMWR), Mask Use and Ventilation Improvements to Reduce COVID-19 Incidence in Elementary Schools — Georgia, November 16–December 11, 2020., Jenna Gettings, Michaila Czarnik, Elana Morris, Elizabeth Haller, Angela M. Thompson-Paul, Catherine Rasberry, Tatiana M. Lanzieri, Jennifer Smith-Grant, Tiffany Michelle Aholou, Ebony Thomas, Cherie Drenzek, Duncan MacKellar, May 21, 2021 [Accessed June 11, 2021]
12 Honeywell, Honeywell Hotel Study Suggests Air Purifiers Help Reduce Exposure to Airborne Contaminants., May 26, 2021 [Accessed June 11, 2021]
13 National Bureau of Economic Research, Heat and Learning: NBER Working Paper No. 24639., Joshua Goodman, Michael Hurwitz, Jisung Park, Jonathan Smith, May 2018 [Accessed June 11, 2021]
14 Mayo Clinic, Home Remedies: Healthy use of humidifiers., Dana Sparks, January 2, 2019 [Accessed June 11, 2021]

Danny White is the education market leader for Honeywell Building Technologies. He has 25 years’ experience in the building industry. He is a West Point graduate and received his MBA from Georgia Tech.

Check out all the latest facility management news related to indoor air quality (IAQ) and heating, ventilation, and air conditioning (HVAC).

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