HEPA filters are very common in industrial gas filtration, but there are some common misconceptions about HEPA filters.

Misunderstanding 1: The larger the particle size, the easier it is to be removed by HEPA.

Analysis: The purification principle of the HEPA filter is not simply to filter out particles larger than the mesh like a sieve to purify the air. Instead, it relies on the van der Waals force between the fine particles and the filter to form an adsorption effect. It has a good filtration efficiency for particles above 0.5 μm and below 0.1 μm.

Particles below 0.1 μm do Brownian motion. The smaller the particle, the stronger the Brownian motion, the more times it is hit, and the better the adsorption effect.

The particles above 0.5μm do inertial motion, the greater the mass, the greater the inertia, and the better the filtering effect.

In comparison, particles with a diameter of 0.1-0.3 μm have become difficult to remove by HEPA. This is why the industry defines HEPA filter grades by the filtration rate of 0.3μm particles.

Misunderstanding 2: HEPA can purify 0.3μm microparticles with a purification efficiency of more than 99.97%, so its purification effect on 0.1μm microparticles is not sure, right?

Analysis: Same as the misunderstanding, PM0.3 is easier to break through the protection of the HEPA filter because it is less susceptible to the influence of van der Waals force. Therefore, the filter with a 99.97% effect on PM0.3 may be more effective on PM0.1 Well, even 99.99%.

Myth 3: The higher the HEPA filtration efficiency, the better.

Analysis: Everything is too much, the higher the HEPA filtration efficiency, the greater the resistance, and the actual ventilation volume will decrease. As the air volume decreases, the number of purifications per unit of time will also decrease, and the purification efficiency will decrease.

Therefore, only the most reasonable combination of fan, filter, and air circulation design can achieve an excellent model.

It should be noted that during the initial period of use, the filtration efficiency of the HEPA filter will increase instead of decrease. This is because the accumulation of pollution particles makes the structure of the filter more and more complex. The incoming pollution particles not only stick to the fibers but also stick to the existing pollution particles.

Although the filtration efficiency of the HEPA filter increases, the wind resistance increases, and the overall purification effect decreases.

If you are interested in our products, or have any questions, please feel free to contact us.