Last year, the National Energy Management Institute (NEMI) and the University of California - Davis began working on a white paper providing signatory companies a guide to assessing indoor air quality in California schools.

The white paper was based on a study conducted by UC Davis’ Western Cooling Efficiency Center and the Indoor Environment Group of Lawrence Berkeley National Laboratory. The study found over half of new heating, ventilation, air conditioning (HVAC) systems in schools had “significant problems” within three years of installation, and “the vast majority of classrooms in California continue to fail to meet minimum ventilation rates.” It also reported nearly 20 percent of classrooms had average daily maximum carbon dioxide levels above 2,000 parts per million (ppm), where an adequately ventilated classroom should not exceed a concentration of 1,100 ppm.

When carbon dioxide levels rise above 1,100 ppm it affects cognitive learning, productivity and absenteeism, costing school districts millions of dollars.


Initially, the goal of the white paper was to lay out a plan for certified and licensed testing, adjusting and balancing (TAB) companies to assess, maintain, adjust, and if necessary, repair existing HVAC systems to verify proper and efficient operation as well as safety standard compliance.

Additionally, it would recommend installation of carbon dioxide sensors in classrooms to verify proper ventilation. An HVAC Assessment Report would document the work performed and identify any additional needs to improve the system.

Then, COVID-19 hit.

Once shelter-in-place orders were lifted and there was talk of children possibly returning to classrooms in the fall, questions regarding indoor air quality (IAQ) went from common shop talk in TAB companies to features on the nightly news.

Chris Ruch, director of training for NEMI, and Theresa Pistochini, engineering manager for the UC David Energy and Efficiency Institute, pivoted their plans, edited the white paper, and prepared “Proposed Ventilation and Energy Efficiency Verification/Repair Program for School Reopening.”

hvac in schools

The revised paper outlines an assessment program developed to prepare schools for reopening during the COVID-19 crisis by certifying school facilities with functional air ventilation and filtration systems that meet or exceed OSHA and California Energy Commission requirements. Additionally, they also meet the recommendations for reopening schools set forth by the World Health Organization, the Centers for Disease Control and Prevention, and the American Society of Heating, Refrigerating and Air-Conditioning Engineers (ASHRAE).

“There are the things that make you feel good, like you’re helping — washing your hands, wearing a mask. But there are things occupants of buildings can’t see. They measure the temperature in the space, and they think that’s the end,” says Duane Davies, CEO/chairman National Air Balance Company and president of California’s chapter of the Sheet Metal and Air Conditioning Contractors’ National Association (SMACNA). “This is a very important step to getting kids back into a healthy and safe environment.”

air filter

Since the white paper was released this summer, Davies, along with Paul McGrath, principal, MEYERS+ ENGINEERS in San Francisco, were two of the first to complete an assessment on an independent school in the Bay Area with 7-, 20- and 30-year-old buildings, with only the newest building with an active mechanical ventilation system.

“This assessment has come at a good time,” McGrath says. “Quite a lot of people in the trades have kids in schools, and it’s a great concern.”

When the assessment was conducted at the beginning of August, McGrath wasn’t surprised at his findings. New classrooms built in the last seven years were not receiving requisite outside air. In fact, technicians wondered if the building had ever been balanced.

man working on hvac system
man working on hvac system

“That was fairly illustrative right there,” he says. During the assessment, technicians balanced dampers to boost the outside air. “We left it in a better place than when we started. By spending 20 minutes in each classroom, we were able to make major improvements, doubling the outside air volume. As bad as it was before we performed the assessment and TAB, I think this school was still better than most. It was eye opening.”

Other easier adjustments were to the filters and their proper installation. MERV 13 filters, recommended by ASHRAE, capture 89 percent of virus particles, as well as significantly more outdoor and indoor pollution compared to more standard, MERV 8 filters.

“Some adjustments took a few minutes. Others will require construction,” McGrath says.

hvac system

Because buildings can’t be redesigned and rebuilt, other fixes will take more time and creativity. Older buildings on the school’s campus weren’t designed with ventilation systems. Codes when they were built allowed operable windows to serve as the source of ventilation.

“How could we expect the school to keep the windows open when they are right beside the highway with all the pollution, or even worse, during the wildfires that are becoming the norm,” McGrath says. “They effectively have no fresh air, and this is where the kids are trying to learn.”

Less than half of the classrooms had a ventilation pathway and of those, none receive appropriate outside air or have relief air paths, according to McGrath.

Of the classrooms tested, 56 percent had no active ventilation; moreover, none of those classrooms met code ventilation levels prior to assessment and adjustment, McGrath says. All of the classrooms adjusted were able to meet the requisite ventilation levels for post-COVID occupancy without the installation any new equipment.

“It’s not just a learning issue, it’s one of social equity,” he adds. “Let’s help create a future where all California kids have the best start in life. COVID-19 has given us a good opportunity to hit reset on ventilation for schools.”

testing air quality

Even if school districts agree to assessments, it is still not going to be easy. Due to building age, design and maintenance, TAB technicians may face different challenges than commercial buildings. Davies encourages “initiative and creativity.” Discussing class sizes, building age, maintenance schedules, and complaints from occupants can help make the assessment more accurate and effective.

“The TAB technician is going to have to be proactive to find out what is and what was,” Davies says. “We’re going to have to be thinking outside the box on these.”

“We normally count on TAB technicians to diligently follow the air volumes noted on the design drawings when they balance,” McGrath adds. “In this case, we’re going to need creativity. There may not be drawings as a road map and being scheduled to assess a school for a day might be a one-shot opportunity for technicians to improve kids’ lives.”