What is a HEPA Filter?

We all are well aware of the necessity of air in our life. It is an indispensable element for us to live. But due to many reasons, it gets contaminated, resulting in unhealthy air quality inside your abode. It never really matters whether you stay in a rural town or dense area. The polluted air will eventually create health hazards. So, what is the solution to get healthy air?

There are several technical assistance out there to provide healthy air. One such technology is the HEPA filter and is one of the most reputable and efficient filtration technologies in today’s world. Modern electric appliance brands manufacture their products with HEPA filters to offer you a healthy and peaceful life. However, different companies use various filtration systems.

But these systems might produce byproducts like Ozone, carbon, Nanosilver Filter and ionizers. So, they do more harm than good to human life. Hence, choosing a proper filtration system is a troublesome job. That is why in this article, we are going to talk about the HEPA filter concept, the materials used, and its principal benefits and drawbacks. It will help you get a detailed idea of the HEPA filters.

Also Read: HEPA vs Ionizer Air Purifier

The Concept of a HEPA Filter

HEPA Filter

HEPA is a short form of High-Efficiency Particulate Air. While these filters have become popular in recent years, their technology is not anything new. The technology of these filters dates as far back as during World War II or the development of the atom bomb. Scientists used these filters to trap the particles released during the manufacture of the atom bombs. These filters are capable of trapping about 99.97% of airborne particles of 0.3 microns in size.

Now you might be thinking, why 0.3 microns? Well, scientists refer to that particular size the most because those particles are the hardest to trap for an air filter. Scientists refer to that size as the most penetrating particle size. They are most effective when it comes to evading filters. Now, there is another factor that can cause some problems. There are multiple kinds of HEPA filters found in the market. They have names such as HEPA, ultra HEPA, and more. So, which one do you choose? Well, in most cases, manufacturers use those terms to make their product more tempting.

However, there is a difference between True HEPA and other kinds of HEPA filters based on the standards set in Europe and America. In Europe, a filter can get HEPA certification if it can catch up to 85% of particles that are 0.3 microns in size. But in the USA, a filter can only receive a HEPA certification if it can catch up to 99.97% of those particles. Therefore, the term True HEPA refers to the American standard of HEPA filters. The filters that cannot trap 99.97% of those particles do not get the HEPA label.

How Does a HEPA Filter Work?

HEPA Filter Work

So we have learned that HEPA filters can block up to 99.97% of the most penetrative particles in the air. But how do they work? Well, their working process is quite simple. You can think of a HEPA filter as a net. Now, with that in mind, we will look at how it handles particles of different sizes. In a HEPA filter, three kinds of filtration methods take place, each for several sized particles.

Particles that are larger in size

As the HEPA filters work like nets, the way they deal with larger particles is pretty uncomplicated. The net gaps of HEPA filters are generally about 1 micron large. So, any bigger particles than that end up getting stuck into the net itself and are not capable of breaching it. Experts call this process straining or sieving.

Particles that can get through the net

So the bigger particles get stuck in the filter, but what about the particles that can get through? We mentioned that the gaps in the net are around 1 micron in size. So, anything smaller than that can get through the net. These are the 0.3 micron-sized particles that get through the net and follow the air along. However, they are quite heavy when compared to very minute particles. So, they fail to move quickly and get stuck in the fabric of the filter. This method is the interception method.

The miniature particles

The filters do not affect the very minute particles like those smaller than 0.3 microns. But even then, the filter is capable of catching them. That is possible because those particles are so small-sized that they cannot fly in a straight line. Whenever they hit a gas molecule, their lack of sufficient mass makes them bounce around wildly. Because of this, they get stuck in the fabric undoubtedly. Scientists call this method diffusion.

These are the methods that help HEPA filters trap most of the particles present in the air. However, while the straining and diffusion methods are excellent, interception is the most troublesome method to pull off. That occurs in the case of 0.3 micron-sized particles. They are not affected by either of the other methods, and that is why those particles are so troublesome.

The Importance of HEPA filters

Importance of HEPA filters

It should be no surprise that air filters are necessary for today’s climate. And HEPA filters do an excellent job at that. It allows you to protect the indoor air from all small harmful particles. So far, we have talked a lot about 0.3-micron particles. Now, what particles are 0.3 microns in size? Below, we present a table that describes the general dimensions of the particles found in the room.

Particles  Sizes (in microns)
Bacteria1-10
Fine sand65
Human hair17-181
Dust mites100-300
Pollen10-1000
Viruses0.0005-0.3
Smoke0.01-4
Copier toner0.5-15

So, you can see that among the particles present inside the room, only a few are of 0.3 microns size. However, you should never ignore them to protect your health. As most filters cannot catch those particles, they can create the most problems and health hazards. As such, HEPA filters are necessary to clean out the air of such particles. But there is one more type of air filter that exceeds the HEPA filter inefficiency. These filters can catch up to 99.99% of such particles and are known as ULPA filters. Therefore, as per ISO guidelines, the effectiveness of air filters is as follows.

Filter type  Filtration rate
EPA (Efficient Particulate Air filter)85-99.97%
HEPA (High-Efficiency Particulate Air filter)99.97-99.99%
ULPA (Ultra Low Penetration Air filter)99.99%

The above values depend on the efficiency of the filters regarding 0.3-micron particles. So, you can see that HEPA filters are efficient, with only the ULPA filters performing better. Those ULPA filters can be quite expensive in some cases. Therefore, it is necessary to purchase a HEPA filter so that you can breathe clean air.

The materials used to make the HEPA filters.

To make these filters, the manufacturers are using tiny glass thread. These threads are so small that it is the 1-micron diameter in size or less than that. Besides, the making process involves tangling and glass thread compression to make a filter mat media. The mats are smaller than 0.5-micron and allow the filter to trap down 0.3-micron particles.

The Features of The HEPA filter

The HEPA filters also have some features. The features determine why modern manufacturers are adopting this filtration system instead of others. Below we have shared its principal features to offer you some idea about this technology.

  • Hassle-free installation system
  • The pleated configuration ascertains a low-pressure drop.
  • No chance of bypassing
  • High dirt handling capability
  • Much efficient than other filtration methods
  • Excellent mechanical potency

The Principal Benefits of The HEPA Filter

After reviewing the HEPA filter concept, working method, and importance, now it is time to discuss its principal advantages. With technological elevation, the HEPA filtration system is versatile among the manufacturers and excellent user reliability. But if you want to buy any electrical device with the HEPA filtration system, you ought to know its benefits. Additionally, if you have some misunderstanding on the HEPA filter, then the below advantages will surely change your perception of this.

  • A HEPA filter will eradicate toxic contaminants from the air. It will help you and your family against breathing-related problems. Besides, it will protect your lungs from dust or debris.
  • These filters effectively diminish the smoke particles, odors, gases, and fumes.
  • An electrical device with HEPA filter technology can remove pet dander, protecting you from the other allergy-causing molecules.
  • The HEPA filtration system is of much help for people having asthma. It eradicates the mold spores and airborne dust particles by creating a safeguard around them.
  • They can refine very minute particles up to 0.3 microns.
  • These filters do not concede any moisture and lubricant contents to move through it.
  • Several filtration technologies emit Ozone while operating. But the HEPA filters do not produce any byproducts like them.
  • Their efficacy level is a matter of discussion. The HEPA filters are capable of diminishing contaminants at great effectiveness of 99.97%.

The Principal Deficiencies of The HEPA Filter

The HEPA filters also have few drawbacks like all the other filtration methods. So, it is time to look at the deficiencies. But what is the benefit of knowing them? Remember that your well-being is your initial preference, and it is obvious to choose an appropriate filtration technology to protect your health. That is why we have distinguished some deficiencies of the HEPA filtration system in this segment. They are as follows.

  • One of its prominent drawbacks is the form and compactness. The HEPA filters are thick and dense. The shape can hinder the airflow process. As a result, your device needs to work hard to flow the air without any interruption. It may result in consuming more electricity and damage to the system.
  • Remember that these filters have a principal drawback compared to other filters. They cannot trap the small contaminants under 0.3 micrometers.
  • Though the HEPA filters can attack the bacteria and several airborne particles, they cannot destroy them permanently. So if you do not take any further steps, the toxic particles will still create problems through respiratory illness, allergy, and many more.
  • These filters require frequent replacement. The ideal changing period is once every three months. Thus it is not cost-effective compared to other filtration systems.
  • Most of the filters out there are washable. But the HEPA filters might be washable or not, depending on the device you are using.

Can you wash a HEPA filter?

You might clean several filters, but this is not in the HEPA filter case. Cleaning them with water or vacuuming is not appropriate for them. If you wash or vacuum the HEPA filter, it might cause damage to the glass threads.

Final Talk

Hence it is evident why the HEPA filters are one of the best among other filtration technologies. The invention of these filters is of immense help. From capturing the airborne particles at a high percentage of efficiency to improving the indoor air condition by diminishing allergens, the HEPA filters are great to use. It efficiently saves you from several situations like massive smoke infiltration, water contamination, and the excessive VOC level. But remember to replace the filter frequently to avoid any mishaps. So, do not waste time. Do some research about HEPA filters and purchase them to provide you and your family with a healthy and secure life.

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