HEPAfiltered

HEPAfiltered describes air, environments, or devices in which the air has passed through a High Efficiency Particulate Air (HEPA) filter. A HEPA filter is a dense, pleated media designed to capture a large fraction of small particles as air flows through it. In many standards, HEPA filters are specified to remove at least 99.97% of particles with a diameter of 0.3 micrometers, a size often used as a benchmark because it represents a challenging particle size for many filter media. European classifications include H13 (about 99.95%) and H14 (about 99.995%), while U.S. definitions commonly cite the 99.97% figure at the 0.3‑µm MPPS (most penetrating particle size).

HEPA-filtered systems are used in a wide range of applications, including residential and commercial air purifiers, vacuum cleaners, and the exhaust paths of cleanrooms, laboratories, hospitals, pharmaceutical facilities, and some nuclear or industrial environments. They are also integrated into many automotive cabin air systems and other enclosed spaces where particulate control is important.

Performance and reliability depend on proper installation and maintenance. Sealing must prevent air bypass, and prefilters are often employed to extend the life of the HEPA element by capturing larger debris. Filter replacement frequency varies with usage, airflow, and environment; excessive moisture or physical damage can degrade performance or shorten service life.

Limitations include the inability to remove most gases, odors, or volatile organic compounds. For such contaminants, activated carbon or other technologies may be used in conjunction with HEPA filtration. The term “true HEPA” is sometimes used to denote filters meeting the standard, whereas “HEPA-type” may indicate lower or nonstandard performance.