How does the HEPA Filter actually work?

Everyone promotes it, but almost no Buyer knows exactly what a HEPA Filter is and why it is so important for Air Purifiers and Filtering Devices. Named Filters achieve a particularly high Degree of Separation through the clever Application of physical Properties, and with them provide a reliable Result. By making use of the following Processes, HEPA Filters now even achieve a Separation Efficiency of 99.995%..

Inertia Effect

Since the Fibers inside the HEPA Filter are not arranged systematically, the Air does not flow through in a straight line and it has to make its way through the Thread Maze of the Filter Fabric. Particles have a certain Inertia due to their Mass. If such a Particle cannot follow the Movement of the Airflow due to its Mass, it will drift away and be intercepted by the Filter.

Explanation using the Example Car:

If you drive a Car too fast around a Curve, you don't manage to make the Curve and the Weight of the Car pushes the Car further straight ahead. This is exactly how Particles behave in the HEPA Filter. The Fibers in the Filter are randomly arranged, causing the Direction of the Airflow to change permanently, creating " Curves". The faster the Particles move, the easier they are captured.

Locking Effect

Smaller Particles tend to follow Air Streams that pass very close to the Fiber. Often these will nestle close to the Filter Material so that the Diameter of the Particle is greater than the Distance of the Airflow to the Fiber.

Explanation by example:

You are driving on the Highway on the left Lane through a Construction Site. At a marked Lane Change, the maximum Width is pointed out. If there is a wide Vehicle on the other Lane, it is often difficult to pass and since Particles do not have Brakes, they would collide with the Vehicle.

Diffusion Effect

The smallest Particles (<1 µm) do not follow any Currents and are caused to vibrate by colliding with the Molecules in the Air. These then stick upon Contact with the Media Fibers. As the Particle Size increases and the Flow Velocity to the Fibers increases, the Chance of the Particles sticking to a Fiber decreases.