What Is a HEPA After-Filter and How Does It Help Combat COVID-19?

HEPA After filter

Keeping the air in a facility clean is a difficult challenge that most industrial businesses face. The air quality directly affects the health and safety of employees, especially when it comes to containing airborne viruses such as COVID-19. There are many things that can be done to control how clean the air is including installing a dust collection system with the appropriate accessories.

Some brands of dust collectors, like A.C.T. Dust Collectors, have an option to add a High Efficiency Particulate Air (HEPA) after-filter. A HEPA after-filter is an additional filtering process to the clean air before it is returned to the facility where your employees are working.



When dirty air and dust particles are drawn into a dust collector, the filters work to allow only clean air to pass through while capturing the dust particles. As the dirty air flows through the main filters in the unit, it removes the larger particles of dust.  In some cases, ultrafine particulate may pass through the primary filters. A HEPA housing and filters are the solution to capturing those dangerous microscopic particles. The HEPA after-filter  is placed on the clean air side of the unit and will further clean the air before it returns to the building.

A HEPA after-filter is an additional set of filters, typically 24” x 24” x 12” in size, that can be added at the end of the process to further purify the air and capture dust. It is an extra option that can be added to specific applications in given circumstances. So as helpful as a HEPA filter is, you will need to consult a dust collection professionals before just bolting an after-filter housing to your unit.

Here are a few factors you need to consider

  • It is important to know the CFM of your dust collector as this determines the size of HEPA housing you will need.
  • Although a HEPA filter is not a guaranteed COVID-19 preventer, it will assist in purifying the air, which in turn helps prevent the transmission of COVID-19.
  • HEPA after-filters are one part of a multi-step defense strategy.



HEPA after-filters help to ensure that the cleanest air possible is being circulated around the building providing a safer working environment. Your employees will be happier if they are working in a clean and safe environment which then increases employee retention. The cleaner air also helps to prevent the buildup of dust and debris on equipment and makes the maintenance of equipment easier. These are just some of the factors of how a dust collection system and a HEPA after-filter can affect your bottom line .   

The combination of our HEPA filters  and our industry leading MERV-15 cartridge filters help provide the ultimate in air filtration. You may be thinking that your dust collector is capturing every micron when in fact there are a few microscopic particles that are slipping through. The HEPA filter is a great option to protect your employees while capturing the smallest microns.

HEPA after filter on Collector



HEPA filters are able to capture 99.97% of any particulate that passes through the filter, 0.3 microns or larger. These tiny microns are captured in the fibers of the HEPA filter .      

Usually the next question is, how big is a micron?

A “micron” is an abbreviated term for “micrometer”, or a millionth of a meter. To put this in perspective, 1 micron is 1/1,000,000 of a meter, which is approximately .00004 inches. The average bacteria is around 2 microns in size. HEPA filters will capture particulates even smaller than that as they are rated up to 0.3 microns.



Currently, COVID-19 is still surging across the country, and colder weather is driving more employees indoors and into closed door facilities. As a result, there is an increased risk for the virus to spread between employees in your warehouse facility. While face masks and work stations being placed 6 ft apart are recommended, employers can take the next step by purifying the air within the facility.

A HEPA filter on your dust collector to filter the air before returning it into your facility will help reduce the risk of airborne transmission of COVID-19.

Let the experience of our team help your work environment stay clean and safe with our dust collection systems and accessories. A.C.T. Dust Collectors offers solutions for dust collection needs and our expert-level team will walk you through purchasing a dust collection system for your specific application. Contact us today  to learn more about how a dust collector can help your employees stay safe and healthy.


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