HEPA filter: The basicsThe abbreviation, HEPA, stands for high-efficiency particulate air. The HEPA filter itself works by using a fine mesh to trap pollen, pet dander, tobacco smoke, and dust mites contained in the air. This particular action classifies HEPA filters as a type of mechanical air filter.Using a HEPA filterAlthough HEPA filters can usually bought individually, they normally arenâ¤™t intended for use as a single unit. Instead, HEPA filters are usually installed in air conditioners, air purifiers, and other air quality and building environment management systems. As an alternative to a HEPA filter-equipped appliances, some vendors also offer portable and reliable HEPA filter masks.