Before 2020, the average person probably did not think much about the air they breathe — at least not while indoors. Like a reliable car or mobile connectivity, high indoor air quality (IAQ) is easy to take for granted until it is no longer a guarantee. Just ask any parent, teacher or school administrator who has questioned whether it is safe to return to in-person learning as the pandemic lingers: a school building’s IAQ is now on their radar. The bigger question is why was it not a priority long before COVID-19?

According to the EPA, when IAQ is poor, occupants can experience illnesses such as asthma, fatigue, irritation and headache. Multiple studies have shown IAQ can directly impact students’ health and learning abilities. A paper published by a researcher at the Lawrence Berkeley National Laboratory found “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.” University College London and University of Cambridge research found air quality inside classrooms was actually worse than the air quality outside.

According to GAO’s national survey of U.S. school districts, more than half of the country’s public school districts need to update or replace multiple building systems or features in their schools, and 41 percent of districts need to update or replace HVAC systems in at least half their schools (approximately 36,000 schools nationwide). It is time to prioritize the quality of air children breathe while at school.

After more than a year of being hyper-aware of the risks of poor ventilation and IAQ, parents want reassurance that a school’s IAQ is within acceptable levels for their students — as do the educators, administrators and employees who spend as much (or more) time in schools as students. That means school facility managers have an important role to play in improving IAQ within school buildings.

Understanding How to achieve ideal IAQ

Considering children in the U.S. spend an average of 1,000 hours each year in school, IAQ is incredibly important in this environment – especially because the concentration of some pollutants can be two- to five-times higher indoors than typical outdoor concentrations.

Many factors go into IAQ, including how a building is designed, outfitted and managed. While FMs must determine their county, region or industry’s specific rules and regulations for commercial buildings — which may have changed as a result of the pandemic — some general recommendations around IAQ include:

  • Audit a building’s air infrastructure to identify its strengths and weaknesses.

  • Keep operational parameters, including temperature, humidity, ventilation and particle count, within optimal ranges.

  • Make the right data readily available to the right people, at the right time, through advanced operational dashboards.

  • Use a combination of on-premise and cloud analytics to monitor real-time results.

Traditionally, building system design emphasized efficiency to minimize construction and operating costs. Now, efficiency is just one factor in building design, and reprioritizing IAQ over efficiency may require updating, retrofitting or replacing outdated HVAC systems. That is where some of the latest technologies can be used — and contrary to what some may think, implementing them does not have to be costly or time consuming. While there will be costs associated with updating HVAC equipment to support better IAQ, ripping and replacing equipment and starting from scratch is not the only solution for buildings. Modifications or retrofits to existing equipment can be a cost-effective way to improve IAQ.

Total costs will vary depending on school age, building square footage and other factors, but the Lawrence Berkeley National Laboratory paper found that the net annual costs of increasing ventilation rates in schools range “from a few dollars to about US$10 per person... less than 0.1 percent of typical public spending on elementary and secondary education in the United States.”

Ventilation

Ventilating small spaces, such as a house or apartment, may require little more than opening windows, but in larger commercial spaces like schools, effective ventilation requires bringing in oxygenated air from outdoors and removing stale indoor air.

Schools should avoid shutting down HVAC systems. Building air should be purged by extending the operating times of HVAC systems to run before the earliest students and staff arrive for the day and after the last occupants have left for the night. When possible, schools should also 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 percent or the maximum amount possible.

Air quality sensors

Stale indoor air can contain particles, gases and volatile organic compounds (VOCs) — the last of which can come from building materials, cleaning products and certain types of paints. Harvard T.H. Chan School of Public Health research found improving indoor environmental quality by lowering concentration of VOCs improved test subjects’ cognitive scores by up to 101 percent, indicating a low- or no-VOC school environment can help students learn better.

Beyond pollutants, the temperature and relative humidity of indoor air also affect students. Researchers found higher air temperatures resulted in lower grades on tests that evaluate students’ reading and math skills. High humidity can promote bacteria and mold growth 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. ASHRAE research shows keeping relative humidity in the 40-60 percent range can decrease occupant exposure to infectious particles and reduce virus transmission.

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. It is possible to add new sensors too, allowing FMs to cost-effectively outfit their school facilities.

Advanced cleaning technologies

The Harvard T.H. Chan School of Public Health suggests “filtration of indoor air, supplement[ed] with portable air cleaners” can be used to achieve better IAQ within school environments. Air filtration and cleaning technologies capture contaminants that can linger in the air, and one of the latest innovations in air quality is the use of electronic air cleaners (EACs), which use an electric charge to help remove solid and liquid impurities from the air without impeding air flow. EACs apply energy only to the particulate matter to be collected without significantly impeding the flow of air.

EACs can be paired with a UV system that emits ultraviolet light, which, when used properly, has been shown in laboratory testing to damage the DNA structure of certain microbes at the cellular level and inactivate various viral, bacterial and fungal organisms. Some EACs with UV systems are able to be installed inside a commercial HVAC system as a retrofit due to low pressure drop, so FMs do not need to remove old equipment and install a new system entirely — another way to upgrade at a lower cost while also recouping some of the cost in the form of energy savings.

Additionally, HEPA filters are one of the most effective defenses for airborne pathogens because of their high-capture efficacy. HEPA filters can be at least 99.97 percent efficient at filtering particles in standard test results, according to Radiation Protection Systems.

Real-time analytics

The World Green Building Council notes IAQ is just one of a range of tools and strategies that should be employed to make buildings safer but adds, “It is clear that an effective approach should... encompass an increased focus on the monitoring and management of air quality.”

A properly configured building management system (BMS) that takes all aspects of a building and occupant needs into consideration — paired with analytics and sensing technology — can give FMs the insight and control they need to create a healthier built environment. Centralized monitoring and control via dashboards make management of a school simpler and more user-friendly while supporting IAQ strategies. Analytics systems can be integrated into a BMS, allowing FMs to monitor humidity, ventilation, temperature, pressure and pollutant levels through real-time data on dashboards. FMs also can run reports to analyze historical data and spot trends.

A BMS 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 in use certain days of the week or times of day) — which can lower overall energy costs.

Better IAQ, better schools

Air may be invisible, but most people will never take IAQ for granted again. As awareness of the importance of IAQ grows, authorities and governments may enact more laws and regulations to keep pace with science.

And, importantly, there is not one single solution to creating better quality IAQ. The “Swiss cheese” model of risk management — first proposed by University of Manchester researcher James Reason in 1990 — serves as a reminder that the best way to prevent issues and eliminate any single points of failure is layering together different layers and types of defenses.

To improve school buildings to support the success of everyone inside them — in the near term as well as in the future — FMs must design a multilayered indoor air quality strategy for school facilities that leverages IAQ best practices and the latest technologies.