Very briefly, a Hepa air purifier is an air purifier with a HEPA filter as the main filter. But what is a Hepa filter? HEPA was originally developed for aerospace, but is now also used in air purifiers to filter pollution from the indoor air. HEPA literally means: High Efficiency Particulate Air. HEPA are air filters that retain between a minimum of 85% and a maximum of 99.999995% of all dust particles (most penetrating particle size) of 0.1 micrometer (µm), depending on the specific filter type. A HEPA filter is specified in the European Union Standard 1822:2019 and can be found in several classifications:
| E10 | > 85 % | — |
| E11 | > 95 % | — |
| E12 | > 99,5 % | — |
| H13 | > 99,95 % | > 99,75 % |
| H14 | > 99,995 % | > 99,975 % |
| U15 | > 99,9995 % | > 99,9975 % |
| U16 | > 99,99995 % | > 99,99975 % |
| U17 | > 99,999995 % | > 99,9999 % |
Only if a filter falls within the above class, it may be called a HEPA filter. An H13 or H14 filter is usually recommended when purchasing dust extraction with HEPA filter and this is also what Euromate offers in its solutions. This rating indicates a filtration of 99.75% and 99.97% respectively, so all dust particles larger than 0.1 micrometers (µm) are retained.
How does a Hepa air purifier work?
A HEPA air purifier contains a fan that sets the air in motion. On the one hand, this creates a suction effect (the air is attracted). On the other hand, the air that goes through the HEPA air purifier is blown back. The great thing is that because of the air that is set in motion, an air cleaning application can be added by placing a HEPA filter. As already mentioned above, the HEPA filter has a number of classifications. With this one knows to what size the particles are removed.
In practice: which particles can a HEPA air purifier filter and which not?
A HEPA air purifier removes particles as small as 0.1 microns from the air with an effectiveness of 99.97%. How small is 1 micron actually? One micron is one millionth of a meter (so very small). A hair is about 70 microns thick and barely visible to the naked eye. A HEPA air purifier removes a wide range of contaminants from the air such as coarse dust, fine dust, components of smoke, mold, viruses, bacteria, aerosols, pollen, dander and allergens from the house dust mite.
The indoor air in the medical sector and care, but also in schools, companies, etc. is polluted by all kinds of contaminants that can be filtered with a HEPA filter. This makes the air clean again. Air purification is also really necessary, because our nose, mouth and throat simply cannot absorb all contaminants and they therefore end up in the lungs. There they cause all kinds of complaints: asthma, respiratory problems and “sick building syndrome”. A HEPA air purifier ensures that all these complaints are drastically reduced or even solved!
A HEPA air purifier must be maintained periodically to ensure proper functioning. HEPA filter gets dirtier and dirtier due to (intensive) use. There will come a time when it needs to be replaced. The costs of this are small, but it is really necessary to be able to continue to guarantee clean air. HEPA filters are disposed of as waste after use and are therefore not reusable, unlike an air purifier with an ionizer.
Can a HEPA air purifier filter viruses (such as SARS-CoC-2) from the air?
Virus particles will always be surrounded by a cocoon of breathing fluid (aerosols). The total diameter of these aerosols including the virus particle depends on the air humidity but cannot be smaller than the dimension of corona virus particles. These have a size of 0.12 µm. There is then an aerosol liquid around it. Based on the filter efficiency and the aerosol dimensions that may contain the corona virus, it is concluded that a HEPA H13 will capture this virus. This reduces the aerosol concentration that may contain the virus in a room during the operation of the system.
