Do Air Purifiers Work for School Classrooms?

Schools have long been a breeding ground for many illness-causing germs. Several factors contribute to this, like having large groups of people in confined spaces, or insufficient cleaning of communal spaces and features. School-aged children are more susceptible to illnesses because their immune systems are still developing, so parents and schools must take necessary precautions and ensure the students’ safety.

As we continue to ease out of the pandemic, there remains a heightened awareness for hygiene and health, especially for airborne pollutants and disease-causing germs. Can air purifiers help keep students from getting sick in school?

Are Air Purifiers Effective in School Classrooms?

Yes, air purifiers are effective in capturing disease-causing pollutants in school classrooms, but only if they are built with the right filters. To ensure maximum air filtration, go for a purifier with a true HEPA filter. HEPA (high-efficiency particulate air) filters were first developed by the U.S. Department of Energy to protect people from airborne contaminants due to nuclear testing in the 1940s.

Don’t be fooled by filters marketed as “HEPA-like,” because a true HEPA filter must capture at least 99.97% of airborne particles that are 0.3 microns in diameter. Furthermore, HEPA filters have different levels of efficiency. The Sans air purifier has a HEPA 13 filter, one of the highest HEPA grades, capable of trapping 99.97% of airborne particles that are as small as 0.3 microns in diameter and 99.95% of those as small as 0.1 microns.

How small is 0.3 microns in diameter, and is this enough to protect kids in school? For perspective, most common bacteria range from one to two microns in diameter, while viruses can range from 0.02-0.2 microns in diameter. So, a true HEPA filter can capture most of these microscopic pathogens and prevent them from causing diseases in the body. 

Additionally, the Sans air purifier is equipped with a three-stage filtration system, including a pre-filter to reduce the burden on the HEPA 13 filter and an activated carbon filter to neutralize foul odors and volatile organic compounds. The three filters are protected by a UV-C light which sterilizes the inside of the air purifier, disabling the bacteria and viruses trapped by the filters to prevent them from growing and compromising the air quality. 

Common Airborne Diseases in Schools

These are the top airborne diseases that frequently spread in schools. 

Common Cold

Colds are normally not a cause for concern. However, because many of the symptoms of the common cold are like some symptoms of COVID-19 – stuffy nose and sneezing, sore throat, cough, mild headache or body pain, low-grade fever, and feeling generally unwell – it can be hard to distinguish between the two contagious illnesses and may cause false alarms. 

Studies have shown that children are key vehicles for the common cold. In 2021, researchers in Hong Kong reported a steep increase of common colds among students when they returned to classrooms after almost a year of remote classes. The outbreak was nearly seven times more than in 2017, 2018, and 2019.  These findings parallel the cases observed in the UK, wherein cases of the common cold among adults increased within two weeks of children returning to school, which affirms that school-aged kids are primary carriers of the virus to adults. 

One study indicates that the common cold may be difficult to avoid because surgical masks, while effective against COVID-19 and many other airborne germs, are not as effective in blocking the rhinovirus, one of the most prevalent causes of the common cold. Furthermore, the rhinovirus has a robust outer envelope which enables it to live longer on surfaces and is harder to wash off hands, making them more transmittable. 

Influenza or Flu (Influenza A Virus) 

Caused by the Influenza A virus, the flu is a highly contagious disease that is spread by an infected host via coughing and sneezing. In a study conducted by the University of Arizona, the Influenza A virus was detected in up to 50% of tested school surfaces. This supports the 2015 study by Marshfield Clinic, which indicated that the flu was the cause of 47% of missed school days due to an acute respiratory disease.

While many people might not consider the flu as a serious illness, the numbers prove that it can potentially be critical. According to the CDC, 2019-2020 saw an estimated 35,000,000 symptomatic cases of the flu, as well as approximately 16,000,000 medical visits, 380,000 hospitalizations, and 20,000 deaths. 


Also known as “pinkeye,” this disease can be caused by various kinds of viruses and bacteria, most commonly the bacterium Staphylococcus aureus. Conjunctivitis is typically spread and contracted through close personal contact, coughing, sneezing, and touching an infected surface. 

A 2016 study conducted in Guangzhou found that this bacterium was present on 8% of classroom desks and 12.5% of classroom floors. Because of its highly contagious nature, most children experience pinkeye at least once in their early development stage.

Strep Throat

Primarily caused by the bacteria, Streptococcus Pyogenes, strep throat is a highly transmittable throat infection. The CDC estimates there are between 11,000 and 24,000 cases of invasive strep throat annually in the U.S., and between 1,200 and 1,900 strep throat-related deaths. It’s transmitted by coughing, sneezing, and talking, which makes it far more common among school-aged kids versus adults and children aged below two years old. 

One Nepalese study conducted on 468 students found that 10.9% of the participants were carriers of the Streptococcus Pyogenes bacteria.

Measles (Rubeola Virus)

Measles is an extremely infectious illness because the virus that causes it, the Rubeola virus, can persist in the air for up to two hours after being expelled by an infected person. The virus lives in the mucus in the nose and throat of the infected person and is transmitted via coughing and sneezing. A person can contract the virus when they breathe the infected air or touch their eyes, mouth, or nose after touching an infected surface. 

It’s so contagious that once a child is infected with measles, there is up to a 90% chance that the people in close contact with them will contract it as well. Additionally, according to a 2016 study, it would only take one infected child to cause a school-wide measles outbreak.

Whether at school or home, help protect kids from airborne illnesses with the right air purifier. Shop the Sans air purifier today.