Knowledge King

Fine particles are pollutants that are 2.5 micrometers in size or smaller. You may have seen them abbreviated as particulate matter 2.5 or pm2.5. HEPA (High-Efficiency Particulate Air) filter is one of the best solutions to clean the air.

Does a HEPA filter remove fine particles? A HEPA filter is guaranteed to remove particles that are as small as 0.3 micrometers in size. Therefore, it does remove fine particles. However, there are other methods that can be used in conjunction with a HEPA filter to increase the likelihood of removing even the finer particles, such as activated carbon, UV light, and even upgrading your air filters

A HEPA filter employs several mechanisms to trap particles, and all those methods combined are guaranteed to be effective on fine particles that are 0.3 micrometers in size and larger. In case you’re curious, a HEPA filter uses 4 methods – impaction, sieving, interception, and diffusion.

Particles smaller than 0.3 micrometers may escape until they enter the filter again in the next air change cycle. But sooner or later, the HEPA filter will be able to trap them by diffusion. Meaning that in theory many of those particles will naturally get sucked in across the membrane of the HEPA filter and eventually be filtered out by sticking in the mesh with the larger particles.