Most Penetrating Particle Size (MPPS) refers to the particle size that is most difficult to capture. The MPPS is important to consider when choosing an air filter, as it is the worst-case scenario for particle removal efficiency. For HEPA filters MPPS is generally between 0.1-0.2 microns. The standard determines efficiency based on this critical value. We can say that particles smaller or larger than MPPS are captured at higher efficiency compared to MPPS efficiency.
There are several factors that can affect the MPPS of a filter, including the type of filter media, the thickness of the filter media, and the air velocity passing through the filtration media.
HEPA Filter Efficiency
The minimum efficiency of HEPA filters are 99.95% for class H13 and 99.995% for class H14 at most penetrating particle size (MPPS) according to the EN1822 standard.
We can give an example to explain what removal efficiency means;
The maximum number of particles that can pass through H14 filter is 5 from 100,000 particles of MPPS (0,005×100.000)/100 =5)
The maximum number of particles that can pass through H13 filter is 50 from 100,000 particles of MPPS (0,05×100.000)/100 =50)
