Air Filtration & Purification: A guide for schools & workplaces

19 January 2022

Air Filtration & Purification: A COVID-19 guide for schools & workplaces.

The role that air ventilation & filtration plays in limiting the spread of COVID-19 is complex. Over the course of the pandemic, we’ve learned more about the ways in which the virus can be transmitted. Some schools & workplaces have been scrambling to upgrade their HVAC systems – placing bulk orders for air purifying devices for classrooms and offices.

Air purifiers fitted with HEPA filters are recommended by some bodies to help mitigate the risk of airborne virus transmission. Air purifiers are typically made of a filter (or multiple filters) and a fan designed to suck in and circulate air. As air moves through the filter, pollutants and particles are captured, while clean air is pushed back out into the surrounding space. HEPA filters are designed to meet specific HEPA standards. The standards state that filters must be able to capture over 99.97% of all particulate pollution.



But questions still remain about the effectiveness of these measures and the approach that’s most likely to succeed. We’ve taken a look at different views on ventilation, filtration, air purifiers & the related mitigation measures.

It’s critical that schools, other educational settings & workplaces take steps to provide safe environments for pupils and staff, particularly looking at considering the impact of low indoor air quality. Recommended actions need to be taken to ensure adequate ventilation systems are regularly maintained, and high-grade air filters have been identified as beneficial.

Why is air purification in schools & workplaces important?

COVID-19 particles can live in the air for up to three hours. More ventilation (air movement) and better filtration (air cleaning) helps to cut down on the number of airborne particles that linger when an infected person coughs or exhales indoors. Particularly within either school or workplace environments this is important, as airborne infection is 15 to 20 times more likely to occur indoors than outdoors.

The HVAC systems of large buildings typically filter air before it is distributed throughout a building, so considering upgrading HVAC filters as appropriate for specific buildings & HVAC systems is a good idea. The variety and complexity of HVAC systems in larger buildings requires professional interpretation of technical guidelines, and it is recommended that air filters are upgraded to the highest efficiency possible and compatible with the system.

Understanding the key elements for good air quality in schools & workplaces is important. Analyse the below questions when establishing whether you need to upgrade your filtration & purification systems.


  • How much outside air gets into the building?
  • How often the indoor air gets filtered before being recirculated?
  • How much air inside the building recirculates from one place to another?


Effective air filtration in schools and workplaces use HEPA filters to successfully capture virtually all airborne particulate contamination that goes through the air purifiers filters. Further to the removal of viruses and bacteria from the air, HEPA filters are effective in reducing traffic pollution – which has been a significant concern when air pollution penetrates into schools and workplaces and effecting their air within the building.

Experts agree that proper ventilation does help prevent COVID-19 spread, as the virus is airborne. For many, working from home became routine, meaning that as the transfer back to schools & offices continues, many will want the reassurance that maximum measures are taken to prevent transmission of COVID-19 and air quality is improved. There are four critical issues that businesses & schools should consider when choosing an air purifier.


  • How efficient are the devices’ filters?
  • Does it have a high clean air delivery rate (CADR)?
  • Is there an option for a service to maintain the filters safely?
  • Is it cost-effective?


With portable air purifiers, employers & schools are acknowledging a right to breathe safe air. Contact one of our team about HEPA filters & our personalized HEPA filtration systems. You can read more about HEPA Filtration in another article here.