School Teachers Nationwide Are Concerned About Air Quality in Classrooms – But Many Are Turning Down or Off In-Room Air Purifiers Due to Noise

National survey shows two-thirds of K-12 educators are concerned about classroom air quality and nearly 70% of teachers are turning down or turning off portable, in-room, HEPA air purifiers – one of the most frequently deployed air cleaning technologies in schools – because of student complaints and impact on teaching

CHARLOTTE, NORTH CAROLINA (November 23, 2021) A new national survey of K-12 teachers, commissioned by Global Plasma Solutions, shows that more than two-thirds are turning down or turning off portable, in-room, HEPA air purifiers (one of the most frequently deployed technologies) as a result of the noise they can generate in classrooms. Turning the portable units down or off reduces or eliminates the impact they can have on airborne pathogens and particles, potentially impacting more than 35 million students1 across the U.S.

Key findings from the survey of 750 public and private school educators underscore the importance of comprehensive air quality solutions – from increased ventilation to emerging filtration technologies – and the importance of using a range of modalities tailored to the unique needs of each local school district.

Specifically, teachers report the following:

  • Two-thirds (67%) of K-12 educators report being concerned about the air quality in their classrooms. Fewer than one-in-four teachers (23%) are extremely confident that the air in their classrooms is clean and safe.
  • Nearly seven-in-ten (69%) of K-12 teachers in the survey turn off or turn down their in-room portable HEPA filters due to the noise they produce.
  • Two-thirds (67%) of teachers often have the portable HEPA filters in their classrooms set to a level below “High” (including off) – most air cleaning systems are designed and tested with the expectation that portable air filters will run at maximum power.
  • Four-in-ten (40%) of teachers surveyed say that the noise levels from in-room air filters makes it harder for them to teach or harder for their students to learn. Three-in-ten (31%) report that students ask for in-room filters to be turned off or down either daily or weekly.

“Indoor air quality is complicated, especially in high traffic buildings like schools. Complex issues demand comprehensive solutions that work hand-in-glove with one another as part of a multi-layered approach to safely deliver cleaner air,” said Glenn Brinckman, chief executive officer of Global Plasma Solutions. “Portable indoor HEPA air purifiers can be part of the equation. But like any standalone technology, they are not silver bullets for solving indoor air quality. It is critical that school systems look carefully at how their systems work in real world settings and in different kinds of school conditions to ensure that they are truly delivering the air quality results needed for their students and teachers.”

According to the U.S. Department of Education National Center for Educational Statistics, Digest of Educational Statistics, more than 60 million students and teachers are in classrooms each day throughout the school year. Many schools, particularly older ones with aging HVAC systems, have invested in portable in-room HEPA filters among other air cleaning technologies.

For a more detailed overview of the survey’s findings, see below. To learn more about the challenges of maintaining indoor air quality in schools, please click here.

1 Based on data from Hanson, Melanie. “K-12 School Enrollment & Student Population Statistics”,, September 19, 2021,

About the National Teachers Survey:

The survey was conducted by Group SJR on behalf of GPS. 750 teachers from both public and private schools in 47 states who have portable HEPA filters in their classrooms participated in the online survey between September 10-30, 2021. This included elementary (294), middle (188) and high school (268) teachers.

About Global Plasma Solutions:

Since its founding in 2008, GPS’s NBPI technology has been installed in thousands of locations, including research labs, healthcare facilities, schools, universities and airports. NPBI uses a unique and patented low energy, soft ionization technology application that quietly works in concert with HVAC systems as part of a multi-layered approach to help reduce airborne particles and improve indoor air quality. GPS is one of the only manufacturers in the world to offer UL 2998 certification, UL’s stringent zero ozone emissions safety standard, across its entire brand portfolio. To learn more, visit GPS’ website.


Stephen White

National Survey of Teachers with an indoor portable HEPA filter device in their classroom


The global COVID-19 pandemic has shined a spotlight on indoor air quality (IAQ), perhaps none brighter than on IAQ in schools, where one-sixth of the U.S. population spends time on any given weekday during the school year. Since the beginning of the pandemic, many school districts have purchased and installed portable indoor HEPA air filtration devices (HEPA filters) in classrooms as part of a multi-layered approach to improving IAQ to help facilitate a safe return to in-person learning.

GPS commissioned a national survey to capture K-12 teacher attitudes, observations and practices around efforts to improve IAQ in classrooms, including use of portable HEPA filters, to help understand potential impacts on the teaching and classroom atmosphere.

Impacts of HEPA Filters on the Classroom Environment

Many teachers report that the HEPA filters are disruptive and that their students frequently request that they be turned off or down.

  • Nearly seven-in-ten (69%) of teachers who have a portable HEPA filter indicate they turn off or down the HEPA filter due to noise.
  • 85% of teachers indicate they are able to turn the HEPA filters on and off, while just over three-quarters (77%) of teachers indicate they are able to adjust the settings.
  • Four-in-ten (40%) teachers agree that noise levels from the HEPA filters make it harder to teach/harder to learn. When segmented to High School teachers, the percentage of teachers rises to 47%.
  • Slightly more than three-in ten (31%) teachers indicate that students ask for the in-room air filter to be turned off or down either daily (11%) or weekly (20%).
  • Two-thirds (67%) of teachers indicate they most often have the HEPA filter set to a level below High (including off).

Mask and Vaccine Mandates

There is strong teacher support for mask and vaccine mandates as well as additional technologies to improve indoor air quality.

  • Two-thirds (67%) of teachers indicate they are concerned about the air quality in their classroom and are in favor of mask and vaccine mandates to help ensure the safety of the classroom.
  • 93% of teachers indicate that they feel safer at school when a mask mandate is in place.
  • 77% of teachers support implementing mask mandates for everyone entering a school.
  • 76% of teachers would support school districts mandating vaccines for teachers and all other school employees.
  • Three-quarters (75%) of teachers would prefer to have additional technologies that can eliminate viruses and particles.


An online quantitative survey of 750 teachers from both public and private schools who have portable HEPA filters in their classroom was conducted between September 10-30, 2021. This included elementary (294), middle (188) and high school (268) teachers.