HEPA filters are composed of a mat of randomly arranged fibres. The fibers are typically composed of fiberglass and possess diameters between 0.5 and 2.0 micrometers. Key factors affecting its functions are fibre diameter, filter thickness, and face velocity. The air space between HEPA filter fibers is typically much greater than 0.3 μm. The common assumption that a HEPA filter acts like a sieve where particles smaller than the largest opening can pass through is incorrect and impractical. Unlike membrane filters at this pore size, where particles as wide as the largest opening or distance between fibers can not pass in between them at all, HEPA filters are designed to target much smaller pollutants and particles. These particles are trapped (they stick to a fiber) through a combination of the following three mechanisms:
Interception
where particles following a line of flow in the air stream come within one radius of a fiber and adhere to it.
Impaction
where larger particles are unable to avoid fibers by following the curving contours of the air stream and are forced to embed in one of them directly; this effect increases with diminishing fiber separation and higher air flow velocity.
Diffusion
an enhancing mechanism that is a result of the collision with gas molecules by the smallest particles, especially those below 0.1 µm in diameter, which are thereby impeded and delayed in their path through the filter; this behavior is similar to Brownian motion and raises the probability that a particle will be stopped by either of the two mechanisms above; this mechanism becomes dominant at lower air flow velocities.
Diffusion predominates below the 0.1 μm diameter particle size. Impaction and interception predominate above 0.4 μm. In between, near the most penetrating particle size (MPPS) 0.21 μm, both diffusion and interception are comparatively inefficient.Because this is the weakest point in the filter's performance, the HEPA specifications use the retention of particles near this size (0.3 μm) to classify the filter. However it is possible for particles smaller than the MPPS to not have filtering efficiency greater than that of the MPPS. This is due to the fact that these particles can act as nucleation sites for mostly condensation and form particles near the MPPS.
Product Details
Type: Mini-pleat HEPA filter Gasket: CR,EVA,EPDM,PU
Frame: Extruded aluminum. Face guard: Baking finish
Separator: Hot-melt beads. Filter class(EN1822):H12, H13,H14
Media: H&V Glass fiber, PTFE Recommended final pressure drop.: 500 Pa.
Temperature / Humidity: 70°C / 100% RH
Why choose us
1,Advanced and new machinery equipment
2, More than 10 years’ experience in filtration field
3,Professional exporting sales with 7 years’ experience
4,Closed biggest port ,Shenzhen port
5,Sincere honest and trustworthy
Standard Size
We not only produce all kinds of different normal size Mini-pleat HEPA filter,but also accept all kinds of customized
size Mini-pleat HEPA filter.Please choose what size you want to buy refer to the below table,
Model Dimensions
(W×H×D) mm
| Filter grade
EN1822 | Airflow / pressure drop m³/h / Pa (± 15%) | Unit
volume m³ |
| 610x610x50 | H13 | 603/130 | 0.041 |
| 1170X1170X50 | H13 | 2218/125 | 0.082 |
| 1170x570x50 | H13 | 1080/130 | 0.073 |
| 610x610x70 | H13 | 603/110 | 0.026 |
| 1170X1170X70 | H13 | 2218/105 | 0.052 |
| 1170x570x70 | H13 | 1080/110 | 0.046 |
| 610x610x90 | H13 | 603/85 | 0.033 |
| 1170X1170X90 | H13 | 2218/80 | 0.066 |
| 1170x570x90 | H13 | 1080/85 | 0.060 |
| 610x610x50 | H14 | 603/140 | 0.041 |
| 1170X1170X50 | H14 | 2218/135 | 0.082 |
| 1170x570x50 | H14 | 1080/140 | 0.073 |
| 610x610x70 | H14 | 603/120 | 0.026 |
| 1170X1170X70 | H14 | 2218/115 | 0.052 |
| 1170x570x70 | H14 | 1080/120 | 0.046 |
| 610x610x90 | H14 | 603/95 | 0.033 |
| 1170X1170X90 | H14 | 2218/90 | 0.066 |
| 1170x570x90 | H14 | 1080/95 | 0.060 |
