Air Filters for Schools (2024)

Selection Criteria for Air Filters for Schools to Control Airborne Pollution

The deployment of high-performance air filters in densely populated indoor environments, such as school classrooms, is crucial in combating indoor pollution and airborne infection transmission. However, it's essential that schools apply sensible selection criteria for these classroom air filters to ensure optimal air cleaning results in these demanding settings.

Tip #1: Demand full test reports from independent test laboratories

School's should demand scientific evidence from independent test laboratories confirming that the specific air filters under evaluation (rather than just the technology in them) can effectively remove the types of air pollutants, allergens, or microorganisms that you want to control. If airborne traffic pollution is a primary concern for your school, it's crucial that the air filters reliably eliminate airborne fine and ultra-fine particulate matter. The schoolshould insist on a comprehensive ultra-fine particulate matter removal efficiency test, conducted by a professional and accredited test lab in a test chamber of at least 25 m³. Remember, the faster the school air filters can clear contaminants from the air in the room, the better. Access to the complete test report is essential; donot simply settle for a condensed marketing version of the test report.

Your school should:

Demand scientific evidence of the performance of the school airfilters
Ensure evidence is from an independent and reputable test laboratory
The test should be of the specific air filters under evaluation, not merely the technology
The test should show the effective removal of the specific types of contamination in question
The test should be conducted in a test chamber of at least 25 m³ or more
The quicker the school air filters clean the room, the better
Ask for the complete test report, not just a marketing summary

Tip #2: Do not use air filters with filtration technologies that can produce unwanted and potentially harmful by-products

We do not recommend using air filters in schools that employ electronic air cleaning technologies, such as photocatalytic oxidation, UV radiation, electrostatic precipitation, ozone generation, or ionization. Prominent government institutions and air quality authorities, including the US EPA and the CARB California Air Resources Board, caution against technologies that emit UV radiation or ions. Such emissions can interact with indoor air chemicals and particles, producing harmful by-products. CARB researchers have documented the widespread emission of ozone, formaldehyde, and ultra-fine particles from electronic air filters in numerous studies.

Additionally, electronic air cleaning technologies generally fall short in providing effective air purification and reliably destroying airborne microorganisms. This is because contaminated air typically passes through the air filters at a high rate, rendering the exposure time of infectious microorganisms too brief for effective destruction.

Do not use electronic air cleaning technologies in classroom environments

Tip #3: The school air filters must move enough air while also being quiet

Choose a school air filter capable of providing a minimum of 3 air changes per hour (ACH) for the room's air volume while maintaining an acceptable noise level for that specific environment—particularly in classroom settings. While a high maximum airflow rate (e.g., 400 m³/h) may seem impressive, it holds little value if the school air filters cannot operate at a noise level suitable for the intended indoor environment. Even in heavily frequented spaces, aim for an air filter that achieves at least 3 ACH with a maximum sound pressure level of ≤ 45 dB(A) ± 3 decibels. In environments less sensitive to noise, targeting a maximum sound level of ≤ 50 dB(A) is reasonable. Adhering to these standards ensures powerful air cleaning performance with minimal disturbance, reducing the likelihood of occupants turning off the air filters due to annoyance.

Choose school air filters that achieve several air changes per hour
Make sure the school air purifier achieves the air changes at the appropriate noise level
For a classroom environment, aim for a maximum sound pressure level of ≤ 45 dB(A) ± 3 decibels

Tip #4: Check the length of the guaranteed availability for replacement filters and parts of the school air filters

The manufacturer or reseller must offer a guaranteed minimum period during which replacement filters will remain available after the initial purchase of the air filters. To promote sustainability and deter the purchase of products designed with planned obsolescence, the availability guarantee for replacement filters should extend at least three times longer than the warranty period for the school air filters themselves.

Tip #5: Choose a manufacturer of school air filters with a strong track record in air filtration

Your school should select a manufacturer or brand specialising in the production of high-performance air filtersand replacement filters, with a demonstrated track record in providing solutions for airborne infection and pollution control across various medical and other critical facilities. True expertise in this field necessitates extensive experience in manufacturing air filters and replacement filters, particularly for applications related to airborne infection and pollution control. A company proficient in producing televisions, vacuum cleaners, or document shredders is typically not an authority in air filters manufacturing. Moreover, prioritize manufacturers who produce their filters in-house rather than relying on third-party suppliers. This ensures optimal system integration and dependable air-cleaning outcomes.

Your school should look for air filter suppliers and manufacturers:

With a strong track record of supplying air filters to sensitive environments
That have true expertise in manufacturing air filters
Who produce their filters in-house

Tip #6: An air filter for a classroom environment should offer intuitive controls

The air filters should offer intuitive controls that provide easy access to advanced settings. Essential control features include:

A selection of at least 6 to 8 fan speeds
An automatic timer allowing the programming of various fan speeds for different times of the day and days of the week (e.g., daytime/nighttime mode)
A filter life monitor that calculates the remaining filter life based on actual usage (running time, fan speed, and pollution levels)
An LED alert for filter replacement
A control panel lock function (child safety lock) to prevent unauthorized adjustments to selected settings