How many levels does the filter have?
Some people who think about it will think of high-efficiency air filters. The word “efficient” is purely a rhetorical slogan? Is there an “inefficient air filter”?
It’s really true, it’s also a filter, it has different uses, and naturally there are different filter levels. Among them, we currently use the classification of European standards and Chinese standards.
- China Standards: It is divided into several grades such as coarse effect, medium efficiency, medium efficiency, sub-efficiency, high efficiency and ultra-efficiency.
- European standards: European standards are more commonly used. Starting from the European standard EN 779-1993, EN 1882-1998, the system is divided into G1-G4, F5-F9, H10-H14, U15-U17 a total of 4 grades, 17 grades. G-F-H-U corresponds to several grades of coarse, medium-efficiency, medium-efficient, high-efficiency and ultra-efficient.
From G1 (filtering rate of coarse particles above 5 microns above 50%) up to U17 (99.999995% for MPPS, ie 0.012 micron).
Attentive readers will notice that on top of HEPA, there is also ULPA, the ultra low particulate, which is not used by ordinary home users.
- MERV (Minimum Efficiency Reporting Value): MERV is divided into 20 grades, of which M15 or H15 is roughly equivalent to European standard F9~H10, and M17 or UH17 is roughly equivalent to European standard H13.
Why are you dividing so many levels?
Because of the complete industrial purification, different efficiencies are required to achieve the combined number of stages, achieving uniformity of air supply volume, purification efficiency, maintenance convenience and economy, overall performance and cost.