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The Air We Breathe: Why Good HVAC Systems Are an Essential Resource for Our Students and School Staff


This post is part of LPI's Learning in the Time of COVID-19 blog series, which explores evidence-based and equity-focused strategies and investments to address the current crisis and build long-term systems capacity.

As many as 10 million students and more than 1 million public school employees who are engaged in some form of in-person learning may be at risk of heightened exposure to COVID-19 due to outdated and poorly functioning heating, ventilation, and air conditioning (HVAC) systems. The risk is greatest in schools serving predominantly students of color and students from low-income families, where districts typically lack the resources to repair or upgrade older, less healthy systems.

HVAC systems are critical to COVID-19 mitigation efforts due to their ability to control airborne pollutants and viruses and to distribute fresh outside air in classrooms. A recent Government Accountability Office (GAO) report, however, estimated that one third of k–12 public schools need HVAC system updates, and more than half have multiple buildings that need system updates or replacements, including HVAC and plumbing. The need is especially pressing for high-poverty districts, which are more likely to rely on state funding to pay for improvements to school facilities and thus are disproportionately impacted by state-level budget cuts—first during the Great Recession and now during the COVID-19 crisis. Building maintenance often receives the largest cuts during budget reductions, meaning that, without targeted intervention, HVAC systems may be under-prioritized at every level.

Why Are Ventilation Systems So Important?

Even beyond the pandemic, HVAC systems play a major role in creating a safe and comfortable learning environment for students and school staff by regulating indoor air quality and maintaining comfortable temperature levels. The Environmental Protection Agency has ranked indoor air pollution as one of the top five environmental risks to public health, and health risks associated with poor indoor air quality (including skin and eye irritation, allergies, and asthma attacks) have the potential to directly impede student learning and achievement. According to a literature review conducted by the Lawrence Berkeley National Laboratory, increased ventilation rates are associated with higher student performance in reading and math, as well as reduced respiratory health effects and absenteeism.

The Environmental Protection Agency has ranked indoor air pollution as one of the top five environmental risks to public health, and health risks associated with poor indoor air quality... have the potential to directly impede student learning and achievement.

HVAC systems are also among the largest energy consumers in schools, and powering inefficient systems imposes a substantial financial and environmental cost. In many schools, energy expenses represent the second highest expenditure after salaries. System improvements could cut the $6 billion that public schools spend on energy annually by up to 25%—that’s a potential savings of a whopping $1.5 billion. Needless to say, initial investments have the potential to yield significant returns that could instead be used to increase student access to well-prepared and effective teachers, school health and wellness supports, after-school and summer programs, or high-quality preschool.

Creating Healthy Buildings

One key to keeping students and school staff safe during the COVID-19 pandemic is reducing the risk of airborne transmission of the virus. The Harvard Healthy Buildings Team recommends that schools prioritize minimizing indoor air recirculation and maximizing fresh outdoor air as much as possible. Air filtration is key when the total elimination of recirculated air cannot be achieved, but installing higher-grade filters, such as HEPA filters or those rated MERV 13 or higher, is too costly for most districts to do on their own. Conducting routine building maintenance, including testing ventilation and filtration performance and replacing filters frequently, is essential for maintaining efficient systems that promote good indoor air quality and yield cost savings. Yet even this level of service can be beyond the budget of many schools.

One key to keeping students and school staff safe during the COVID-19 pandemic is reducing the risk of airborne transmission of the virus.

The Cost of Healthy Air

Very little has been written about the statewide or national costs of improving school ventilation systems. The lack of state or national estimates may have to do with the fact that the more than 96,000 school buildings nationwide range in size, age, and location. These variations mean that it is difficult to establish a single per-building cost for improving HVAC systems. The HVAC system in a school building that is 10 years old may require only a cleaning and some new filters to keep students and staff safe, while a building that is more than 100 years old may require tens of millions of dollars in upgrades, or even a complete replacement of its HVAC system.

For state and federal policymakers to understand the current condition of the HVAC systems in public schools, districts will need to conduct inspections of all their school buildings. However, GAO estimates give a sense of the level of investments needed and where they are needed most. In June of this year, the GAO estimated that approximately 36,000 school buildings in the United States have substandard HVAC systems. The GAO report put the price tag for upgrading to modern ventilation systems at $1 million per building. The cost for new HVAC systems ranges between $30 and $50 per square foot. If half of the 36,000 buildings with sub-standard HVAC systems require upgrades and the remaining 50% require new ventilation systems, it would cost approximately $72 billion to ensure safe and healthy air quality in all schools and classrooms.

The Case for Federal Investment in Healthy Classrooms

School ventilation systems rarely make the headlines, yet they play an essential role in fighting the pandemic today—and providing long-term health benefits to students and school staff even after the threat of the virus goes away. Unfortunately, the schools most likely to need new systems are also the least likely to be able to afford them.

Funding for school facilities primarily comes from local sources (82%), with some state funding (18%) and very little federal support (less than 1%). Local funding for facilities comes almost exclusively from property taxes. This means that schools in communities with low property wealth—often serving students from low-income families and other historically underserved students—are the least able to raise the funds needed to improve HVAC systems. Most states, for their part, are trying to fend off cuts to their k–12 education budgets and are not in a position to increase funding for facilities. In short, the federal government is the only entity that can provide the needed resources to ensure safe and healthy air quality in our schools.

A federal aid package should clearly allow funding to be used for districts to repair or replace their unsafe ventilation systems. Districts need financial assistance for everything from replacing HVAC filters to purchasing new ventilation systems. Without an additional investment by the federal government, about one-in-five public school students and school staff will be at greater risk of contracting COVID-19. These schools are, for the most part, in the same low-income communities of color that have been disproportionately impacted by the pandemic—where people are getting sick and dying from the virus and losing their jobs at higher rates than white and higher-income communities. Longer term, a failure to act means that 20 million students and the supporting school staff will be teaching and learning in unhealthy schools, even after the virus subsides.

Given the stakes, we do not have a minute to waste.