Pollution and toxins in the air are on the rise everywhere, leaving people suffering from breathlessness, suffocation, bronchospasms, severe allergic reactions, etc. As this leads to uncertain changes in weather affecting the masses.
For people, who are suffering from asthma, life is hell like. As a preventive measure and safety precaution to keep you and your loved ones safe, you’re probably looking out for an air purifier because of the increased levels of pollutants in the air.
If you’ve already started searching, it is very likely that you’ve come across the term HEPA used with regard to air filtration.
You might be having many unanswered questions like, What is a HEPA filter? And if you have already heard of it, you may be wonder how it works. To make an informed decision when it comes to buying air purifiers, it important to understand what HEPA filtration is, especially since it is an important and popular form of air purification.
What is a HEPA Filter?
HEPA is an abbreviation, and it stands for High-Efficiency Particulate Air. The point being that a HEPA filter is a High-Efficiency Particulate Air filter. Filters, be it for an air purifier or any other purpose, come with some benefits and claims.
There is something that sets HEPA filters apart from the rest, and that is the fact that their claims are more than just claims. The reason for that being to be called a true HEPA filter, it requires to go through a series of tests that then need to be approved, for the sole reason that you are safe and know exactly what to expect.
According to the Institute of Environmental Sciences and Technology, a HEPA filter is expected to trap 99.97% of particulates that equal to or larger than 0.3 microns. This may cause you to misunderstand that the filter is incapable of trapping particles that are smaller than 0.3 microns. There are a lot of HEPA filters that can do that. It is just that to reach the HEPA name, a certain threshold must be reached.
What is a Micron?
Particles range from extremely tiny, i.e., microscopic to visible to the human eye. A micron is a unit of length which is equivalent to one-millionth of a meter.
Particles are measured using this measure. To understand what one means by micron in terms of physica representation, the thickness of the human hair ranges from 17 to 181 microns, also keep in mind that we cannot see anything less than 10 microns with our naked eye. On the other hand, bacteria range from 0.3 to 60 microns.
Micron Comparison Chart
|Spores||3 – 40 microns|
|Mold||3 – 12 microns|
|Bacteria||0.3 – 60 microns|
|Car Emissions||1 – 150 microns|
|Pure Oxygen||0.0005 microns|
How do HEPA Filters Work?
In simple words, the HEPA filters just trap the contaminant and pollutants in the air in its complex web of fibers. It all depends on the size of the particle. Based on that, this can happen in four different ways, i.e., Inertial Impaction, Interception, Diffusion, or Sieving.
All the larger contaminants are filtered out via inertial impaction and sieving. These larger particles either collide or get trapped within the fibers or are trapped while trying to travel through the fibers. As the medium-sized particles move through the filter, they are grabbed by the fibers via interception and the smaller particles are simply dissipated as they travel through the filter and eventually collide with fiber and are then trapped.
Are all HEPA Filters the Same?
No, not all HEPA filters are the same, that is a popular misconception. There are significant differences in composition and utilization of different HEPA filters. It depends on the type of technology a particular air filter is using to purify the contaminated air.
It depends on the thickness of the fibers used, the number of layers, the environment it is being used in and the frequency of use. A very important factor to consider is what is your main cause of concern, is it the sulphur or spores or both? Once you know what you want, the choice is simple.