HEPA vs. ULPA Filter Systems

HEPA vs. ULPA Filter Systems

Why does AeroShield™ FLOW use HEPA filters instead of ULPA filters?

While ULPA filters are certified to collect more particles in the 0.12-0.4 range, they are only necessary for specialized applications such as microelectronics, laboratories, removing particulates from cleanrooms, or electro-surgical operations. ULPA filters can actually hamper the efficacy of specific air filtration systems like the AeroShield™ FLOW. 

HEPA filters, by contrast, are much more broadly used because they're considered optimal for most biological applications, including healthcare and dentistry. Even hospitals use HEPA for their air filtration needs.

The other main disadvantages that come with using ULPA filters include: Restricted Airflow, Higher Cost, and Shorter Filter Life

Restricted Airflow: The main reason you can't just swap in a ULPA filter for a HEPA filter is that the ULPA filter is more restrictive on airflow. A key difference between HEPA and ULPA is airflow. Air flow is a key indicator of efficiency, especially for our application in extraoral aerosol evacuation - if you don’t have sufficient airflow, you can’t capture sufficient amounts of aerosols to be effective. So high airflow is of utmost importance and using a ULPA filter would significantly reduce the airflow to an unacceptable level without adding significant filtration benefits. This would end up ultimately lowering the air quality in the operatory. 

Higher Cost: Since ULPA filters have denser media and are harder to produce than HEPA filters, they generally cost about 35% more than HEPA filters. The cost of filters is only part of the story. Designing a ULPA system to deliver the same airflow as a HEPA system would require a larger filter to make up for the more restrictive flow, and possibly a more powerful motor, making the entire filter system larger, louder, and more expensive...not ideal for the dental operatory. 

Shorter Filter Life: Another thing that makes ULPA filters more costly is their shorter life, which averages 20-50% shorter than HEPA filters in similar use.