Ten actions for clean air where children learn.

1.Bring quiet, classroom-sized air cleaners into classrooms, starting where the need is greatest

These are unobtrusive HEPA units, sized to the room and quiet enough to run all day without disturbing teaching. They cost about $1,000 per classroom, last 10 to 20 years, and come to roughly $5 to $10 per student per year including filters and labor.

Most districts and networks phase them in, and the right starting point depends on local conditions. Factors worth weighing together include:

• Outdoor air: nearness to highways, bus depots, ports and industrial sites, and local PM2.5 levels, including how often bad-air days occur.
• Student health: asthma rates and other health indicators in the school community.
• Buildings: age, condition, and whether the school has mechanical ventilation.
• Long-term plans: the facilities master plan, which can show where classroom units fill a gap before major HVAC work and where they complement upgrades already planned.

2.Get full value from the HVAC systems you already have

Many classrooms get less fresh air than their systems were built to deliver, often because of stuck dampers, disabled controls or fans set to cycle off. A system check can find these problems, and an engineer can confirm which systems can take higher-grade MERV-13 filters. Running fresh air at design levels whenever students are in the building, starting before they arrive, and retesting on a regular schedule help keep the gains in place.

3.Cut pollution at the school gate

Children also breathe outdoor air at drop-off, at recess and on the bus. Cities and districts have several options for cutting pollution around schools: enforcing no-idling rules for buses, delivery trucks and parent cars; moving the first electric buses onto routes that serve the most-exposed schools; and siting new schools away from highways and freight corridors where possible, with strong filtration where a site can’t move. These steps vary in complexity and cost, and they reach children outside the classroom.

7.Adopt a written clean-air standard for every classroom

A written standard gives everyone the same target, and it outlasts changes in leadership and budgets. It can be adopted as school or network board policy, ideally with a matching city council resolution, with targets for both the equipment and the air.

Noise belongs in the standard rather than a footnote. It is the most common reason pandemic-era units failed: they were loud, teachers turned them down or off, and the air went back to what it was. The 45 dBA figure is already a compromise, since the classroom acoustics standard (ANSI/ASA S12.60) sets 35 dBA for an empty room.

8.Make the standard binding on everything you buy and build

Writing the standard into purchasing and building rules means each new unit and project meets it without a fresh decision. The Model RFP we developed with the Center for Green Schools at the U.S. Green Building Council turns the targets into bid language a district can issue largely as written. It scores bids on independently tested clean air delivery rather than manufacturer claims, and requires UL 507 safety listing. The same targets can go into design standards for new construction, major renovations and HVAC replacements.