HEPA filter
Sign in to saveHEPA (, high efficiency particulate air, or high efficiency particulate arresting) is an efficiency standard of air filters. A HEPA filter is an air filter meeting such a standard.
Article
19 sectionsContents
- Mechanism
- Gas filtration
- Pre-filter and HEPA filter
- Specifications
- Specifications for respirators
- Marketing
- Efficacy and safety
- Applications
- Biomedical
- COVID-19
- Vacuum cleaners
- Heating, ventilation, and air conditioning
- Vehicles
- Airlines
- Motor vehicles
- History
- See also
- References
- Further reading
HEPA (, high efficiency particulate air, or high efficiency particulate arresting) is an efficiency standard of air filters. A HEPA filter is an air filter meeting such a standard.
A HEPA filter must satisfy certain levels of efficiency. Common standards require that a HEPA air filter must remove—from the air that passes through—at least 99.95% (ISO, European Standard) or 99.97% (ASME, U.S. DOE) of particles whose diameter is equal to 0.3 μm, with the filtration efficiency increasing for particle diameters both less than and greater than 0.3 μm. HEPA filters capture pollen, dirt, dust, moisture, bacteria (0.2–2.0 μm), viruses (0.02–0.3 μm), and submicron liquid aerosol (0.02–0.5 μm). Some microorganisms, for example, Aspergillus niger, Penicillium citrinum, Staphylococcus epidermidis, and Bacillus subtilis are captured by HEPA filters with photocatalytic oxidation (PCO). A HEPA filter is also able to capture some viruses and bacteria which are ≤0.3 μm. A HEPA filter is also able to capture floor dust which contains bacteroidia, clostridia, and bacilli.