What is a HEPA filter? How does it work?

When investing in an air purifier, you will be advised to choose device with HEPA filters. HEPA filters are to air purifiers what 3D glasses are to 3D movies; essential that is. Here is everything you need to know about this feature in air purifiers.

HEPA is an acronym that means High Efficiency Particulate Air, so a HEPA filter is a filter that is Highly Efficient while filtering air. Filters, whether for an air purifier or other implementation, come with many claims and benefits.

According to The Institute of Environmental Sciences and Technology, a true HEPA filter must trap 99.97% of particulates 0.3 microns or bigger. This does not mean that the filter cannot ensnare particles smaller than 0.3 microns, because quite a few HEPA filters can; it is simply the verge that must be reached in order to brand a product with the HEPA name.

How it Works?

To put it plainly, HEPA filters trap air contaminants in a compound web of fibers. Depending on the size of the particle, this can happen in four diverse ways: Inertial Impaction, Interception, Diffusion, or Sieving.

Bigger contaminants are trapped via sieving and inertial impaction. The particles either are trapped while attempting to travel through the fibers or collide with the fibers and become trapped. As they move through the filter, Medium sized particles are grabbed by the fibers through interception. Smaller particles are degenerated as they travel through the filter and eventually collide with a fiber and are trapped before passing through with the air.

A comparison of the size of common pollutants:

●      Spores: 3 – 40 microns

●      Mold: 3 – 12 microns

●      Bacteria: 0.3 – 60 microns

●      Car emissions: 1 – 150 microns

●      Pure oxygen: 0.0005 microns

It is important to be aware of the fact that not all HEPA filters are alike. Some brands couple the HEPA feature with others like activated carbon, ozone, ionizing, and UV technology to make the air purifiers more efficient. HEPA filters are usually classified using the five letters A through E, based on how well they resist airflow and capture particles. Type A that while still meeting the basic criteria for HEPA, are the least effective. Type E, at the opposite end of the scale, are military grade filters competent in coping with radiological, chemical or biological particles. HEPA filters also have a classification based on whether filters are fire resistant (type 1) or semi-combustible (type 2).

HEPA filters have proven to be advantageous for use in both homes and offices. Conventional vacuum cleaners do not adequately trap dust particles and they also expel minute air pollutants back into the air we inhale.  Switching from air purifiers with traditional filters to those with HEPA filters greatly improves indoor air quality. HEPA filters help prevent flare ups to those who suffer from asthma or allergy symptoms as they trap the minute pollutants that trigger these reactions.  HEPA filters can help eliminate smoke, dust, mold, bacteria, and pollen.

Head over to Carypure to find the most efficient air purifiers with HEPA filter.