When it comes to air filtration, HEPA and ULPA filters are two of the most popular options. Both are designed to trap very small particles from an air stream, but ULPA filters are more effective at removing submicron particles than HEPA filters. ULPA filters are 99.9% effective at removing particles of 0.12 microns or more in diameter, while HEPA filters are 99.97% effective at removing particles 0.3 microns in diameter or more. Both HEPA and ULPA filters consist of countless tiny threads of randomly arranged borosilicate glass microfibers.
The design of the HEPA filter is based on the fact that the worst-case particle size is 0.3 micrometers, making it the recommended standard for those responsible for minimizing dust and airborne pathogens during construction in healthcare environments. However, when it comes to removing pollutants from the air, there is a filter that technically blocks more pollutants than a HEPA filter. This filter is known as an ultra-low particulate air (ULPA) filter, which requires 99.99% efficiency with a target particle size of 0.1 micron. With a design similar to that of a HEPA filter, ULPA filters have a dense network of randomly arranged fibers. In addition to trapping more and smaller particles than HEPA filters, ULPA air purifiers also require an additional step for maximum effectiveness: UV-C light treatment. This process helps reduce the amount of pollutants that pass through the filter by first passing through the HEPA filter and then going through the UV-C process. Overall, ULPA filters are more effective than HEPA filters when it comes to trapping very small particles from an air stream.
However, for those responsible for minimizing dust and airborne pathogens during construction in healthcare environments, HEPA filters are still the recommended standard.
