September 2, 2021
Last Updated On:
July 12, 2022

True HEPA vs. HEPA Filter: What's The Difference?

Portable systems often contain essential filtration media such as a HEPA filter; however, not all "HEPA" filters are made the same.

Last Updated On:
July 12, 2022

Proper air filtration and air purifiers are vital to improving air quality in all indoor spaces. While some areas may require more filtration, clean air is essential for overall public health in light of the COVID-19 pandemic. While there is a focus on viral mitigation strategies, reducing airborne contaminants, particulate, and biological aerosols should now be a top priority. One of the most common methods to reduce these airborne contaminants is mechanical and electronic air purifier systems.

These portable systems often contain essential filtration media such as a HEPA filter. However, not all "HEPA" filters are made the same and are often rated to capture particulate of varying micron sizes. When researching portable air purifier solutions for your facility, knowing the difference between HEPA, True HEPA, HEPA-Type, and other HEPA filter types is crucial. 

These considerations regarding HEPA filters are essential when your goal is to reduce aerosol viral transmission. Read on to learn more about the differences between various HEPA filter types and why you should consider purchasing an air purifier with True HEPA.

Air Quality and Rating Scales

Regarding air quality, facility managers, homeowners, and government officials should understand an air filter's efficiency to ensure you appropriately address your mitigation needs for clean air. There are many different filters, but you will still have poor air quality if the filter lets too many particles through. 

There are specific rating scales that determine the efficiency of a filter. The commercial industry standard is the MERV rating scale, which rates filters from 1 to 20. As you may have read, the CDC COVID-19 guidelines recommend using a minimum of a MERV 13 filter within HVAC systems. 

Another air filter rating measurement is HEPA. HEPA filters can be used in any setting, including industrial, commercial, healthcare, and by consumers. Also, there are many variations on HEPA, including HEPA like, Permanent HEPA and True HEPA. 

PM 2.5 Indoor Air Quality Monitor

What is a HEPA Filter?

HEPA is a type of pleated mechanical air filter known as a "high-efficiency particulate air filter" and refers to its air quality cleanliness measurement developed by the Department of Energy (DOE) following the Manhattan Project in the 1940s. 

As defined by the DOE, HEPA filters can capture up to 99.97% of airborne particles sized 0.3 microns (µm), also known as the most penetrating particle size (MPPS). HEPA filters theoretically can remove:

  • Dust
  • Pollen
  • Pet dander
  • Viruses
  • Bacteria
  • Mold
  • Or, any airborne particles with a size of 0.3 microns

How Do HEPA Filters Work?

Understanding how HEPA filters work will help you understand why you should be opting for a True HEPA over a basic HEPA. 

A HEPA filter is a fibrosis air filter typically made of plastic fibers (polypropylene), fiberglass, or borosilicate glass fibers. These fibers are bound closely together (often using a 5% acrylic binder) to restrict certain particles from getting through. 

Most HEPA filters are mechanical and commonly paired with electrostatically charged filter media, like in electronic air cleaners, which help move the air through the filter in a two-stage process. In this two stage-process, the particulate air has an electrical power source that charges the particles that pass through the filter.  

In Sanalife products, this charge is ionization, and it helps to encourage particles to bind to other particles, making them easier to capture by the air filter. The charcoal pre-filter also captures smoke, odor, harmful gases, and volatile organic compounds (VOCs), which HEPA filters can't catch. Leveraging ionization technology allows you to capture more airborne debris so that the HEPA filter can do its job more efficiently.

A HEPA filter on its own is a mechanical filter that will capture any airborne particles through a series of diffusion, interception, and impaction. The airflow, the randomness of the media filter, and the fiber types create a barrier of resistance that captures particles as the air passes through the filter. 

As you can guess, a filter with more spread-out fibers won't be as effective as it would let more particles pass through. 

PM 2.5 Capable True HEPA Filter

True HEPA vs. HEPA Filters

HEPA filters are the most commonly used filtration technology in both commercial and residential settings. It is partly due to its effectiveness at capturing 99.97% of particles 0.3 microns and is efficient in commercial and residential spaces.

A True HEPA filtration device or filter is the only type of HEPA filter that truly conforms to the DOE standard for HEPA filtration, has the highest efficiency, and hits the 99.97% threshold.

If the HEPA filter does not meet the DOE's standards for HEPA filtration, then it is not considered True HEPA. While the filter could perhaps still capture particles sized 0.3 microns and capture a high percentage of them, unless confirmed a True HEPA, it cannot claim to meet the DOE HEPA standards.

When purchasing a True HEPA, you should be able to source third-party testing that also proves the brand went through the proper steps to adhere to the DOE's HEPA standards and test its efficiency.

Explore Our Custom Air Quality Solutions

HEPA-Type Filter vs. True HEPA

A HEPA-type filter is genuinely an inferior version of the True HEPA. Unfortunately, due to trademarking, a HEPA-type filter can be sold under pretenses to trick consumers into believing that the HEPA-type is close to or as effective as the True HEPA. 

A HEPA-type filter only has an efficiency rating of 99%, and they are effective at capturing 0.2 microns sized particles. While this may look more impressive (compared to the 0.3 effectiveness of the True HEPA), it is not.

The 0.3-micron particle is the MPPS (most challenging particle to capture), and through the technology of the True HEPA, the 0.3 micron-sized particles bounce into particles of 0.1 microns in size. They can capture these smaller particles (usually viruses and bacteria such as the common flu virus). 

Removing HEPA Type Filter From Portable Air Purifier

Can I Get a HEPA-Type Filter?

If you get the HEPA-type filter, you know how efficiently your air filtration device is working and if you're getting clean air. And if you need to reopen your business during the COVID pandemic, you need to trust that the filter within your air filtration system will efficiently clean the air.

To provide the cleanest and safest air, you want to get the best filter for your businessoffice spaceschoolhealth facilityorganization, or home. The best way to accomplish your air quality goals is with a True HEPA product.

True HEPAs last longer and can operate 24 hours a day, 365 days a year. You can effectively eliminate dust, pet dander, pollen, bacteria, viruses, and other airborne contaminants with a durable, water-resistant True HEPA filter. 

Sanalife's True HEPA portable air purifiers have multi-stage air cleaning power to provide the cleanest air possible. View our portable True HEPA air purifier systems by visiting

Let's Build Your Solution Together

Uncertain where to begin with an IAQ or disinfection solution for your business, school, or facility?

Sanalife Newsletter Signup Arrow Icon

Sign Up For The Sanalife Monthly Newsletter

Our best stories on indoor air quality and facilities management delivered straight to your inbox.

By signing up, you agree to our Statement and to receive marketing and account-related emails from Sanalife. You can unsubscribe at any time.