Hepa filters are the number one choice for air purification across most industries. Hepa filters cannot be cleaned to remove particulate and dust loading and must be replaced as a complete assembly often at significant yearly cost.
Hepa Wikipedia
You may not need that much protection but if you re shopping for an air purifier it s good to know how each filter type performs.
What do hepa filters remove. The hepa standard came about in the 1950s. Normal hepa filter air purifiers can filter viruses. The answer is no.
In europe hepa filters must remove 99 95 iso of particles. In the us they must remove 99 97 of particles. How do hepa filters work.
Today hepa is used as a generic term for highly efficient filters. In america a hepa filter must remove atleast 99 97 of particles which are 0 3 micrometers or larger in diameter. Hepa filters as defined by the united states department of energy doe standard adopted by most american industries remove at least 99 97 of airborne particles 0 3 micrometers μm in diameter.
The energy star branch of the environment protection agency epa defines hepa filters as being able to remove more than 99 percent of all airborne pollutants 0 3 microns or larger a micron is a. The filter s minimal resistance to airflow or pressure drop is usually specified around 300 pascals 0 044 psi at its nominal volumetric flow rate. But what about pollutants that are smaller then 3 microns.
When following the iso or european rules filters that capture 85 of particles but less than 99 95 are called epa filters or efficient particulate air filter. Hepa air purifiers are not a silver bullet. Their capacity to capture particulates as small as 3 microns make them extremely efficient at removing pollutants and improving indoor air quality.
They can filter out viruses from the air in homes offices and schools but other steps such as good hygiene and disinfectants should still be used in conjunction with hepa air purifiers. In one of the more extreme examples gas masks usually contain a hepa filter to remove nuclear fallout bacteria and viruses as well as a carbon filter that eliminates chemical toxins. Hepa filters wikipedia link are made up of a mat of randomly arranged fibres.
As the particle load increases so will the resistance to flow and hence the pressure drop across the filter. Do hepa filters remove vocs.