What Is A HEPA Filter?

24.09.2024

Brooke Kirshne

With the increase in population, industrialization, deforestation, urbanization, and many other things, the air quality in this modern world is decreasing rapidly. This global problem is threatening all life forms on Earth and its environment. Many organizations are trying to fix this issue but it will take time and effort. So a question must be coming into your mind: what should you do now? You must have thought that you’d be safe if you lived inside your home most of the time, and if you were going to do this, think about it again.

Research conducted by the US EPA (United States Environmental Protection Agency) shows that the air quality inside your home is 2 to 5 times worse than the air which is outside of your house. You can’t do anything about the outside air but there’s a way to improve indoor air quality and that is using an HEPA air filter. The word HEPA stands for high efficiency particulate air, an air filter is a medium between air and the HVAC system and HEPA is a filter type that ranks on the top. So in this blog, you are going to learn about HEPA filters. To know every information you must read every section carefully.

In this section, you are about to learn what is a HEPA filter? It is a type of filter that falls in the category of mechanical air filters. These filters are a very important part of your HVAC system which is the heating, ventilation, and air conditioning system of your home. These filters are specially designed and have high MERV (Minimum Efficiency Reporting Value) ratings so that they can capture particles and separate them from the stream of air very effectively and this helps to remove around 99.97% of airborne particles. These filters are made of many randomly arranged fibers using materials like polypropylene, fiberglass, or polyester. The fibers are arranged in a way so they can have a diameter between them less than 1 micrometer. Different sizes of airborne particles are captured with the help of different mechanisms by the mesh made of fibers.

MERV Rating	Removal Of Particles Of Size 3.0 to 10 Microns	Removal Of Particles Of Size 1.0 to 3.0 Microns	Removal Of Particles Of Size 0.3 to 1.0 Microns	Types Of Air Filters
MERV 1	20% Or Less	20% Or Less	20% Or Less	Fiberglass Filters/Washable Filters
MERV 2	20% Or Less	20% Or Less	20% Or Less
MERV 3	20% Or Less	20% Or Less	20% Or Less
MERV 4	20% Or Less	20% Or Less	20% Or Less
MERV 5	20% - 34%	20% Or Less	20% Or Less	Pleated Filters/Electrostatic Filters
MERV 6	35% - 49%	20% Or Less	20% Or Less
MERV 7	50% - 69%	20% Or Less	20% Or Less
MERV 8	70% - 85%	20% Or Less	20% Or Less
MERV 9	85% Or More	50% or More	20% Or Less
MERV 10	85% Or More	50% - 64%	20% Or Less
MERV 11	85% Or More	65% - 79%	20% Or Less
MERV 12	90% Or More	80% - 90%	20% Or Less
MERV 13	90% Or More	90% Or More	75% Or More
MERV 14	90% Or More	90% Or More	75% - 84%	Pleated Filters
MERV 15	90% Or More	95% Or More	85% - 94%
MERV 16	90% Or More	95% Or More	95% Or More
MERV 17	99% Or More	99% Or More	99.97%	HEPA Filters/ULPA Filters
MERV 18	99% Or More	99% Or More	99.997%
MERV 19	99% Or More	99% Or More	99.9997%
MERV 20	99% Or More	99% Or More	99.99997%

How Does A HEPA Filter Work?

The HEPA filter most of the time contains many layers of filter material kept in between the peated separator structures. The layers are woven between the separator plates that help to increase the surface area of filtration material as a result the filter captures a huge amount of airborne particles. This design ensures that the pollutant must go through a consistent thickness of filter material that provides a high filtration efficiency. The contaminants are filtered through many different mechanisms and here they are:

Direct Impact And Absorption

This mechanism is also known as inertial impact filtration because the particle-capturing process starts from here. The large particles are captured in this process because when the air stream goes directly through the filter the big contaminants can’t change their direction and become unable to pass through the filter’s fiber and get stuck. The large particles travel in a straight line so they get absorbed by the filter in the first few layers.

Interception

In this filtration mechanism, the small particles are captured that were able to pass through the fiber layers in the initial stage. These small particles can move with the direction of air to prevent this, the airflow is interrupted in this process of filtration. Most of these particles have enough distance so they can travel through the small space of filter fibers but due to interrupted airflow, some particles are absorbed by the filtration materials.

Indirect Diffusion

You can call this process diffuse filtration also. When the particles get very small, they don’t follow the direction of air because these particles start following Brownian motion which means the particles move randomly in the air. The indirect diffusion mechanism helps to capture these small particles that move randomly and can penetrate the filtration material.

Electrostatic Attraction

As you can understand by the name of this mechanism, electrostatic charge is used to capture particles. The airborne contaminants are attracted to the filtration material with the help of electrostatic attraction. When the small particles are charged they are captured and removed from the air streamline and provide extremely efficient filtration.

Types Of Other Air Filters

In the above sections you learned about the HEPA filters and their functions but there are other types of air filters also available in the market that can help you to capture airborne particles. Every type of filter has a different mechanism and feature to provide filtration. So here are some of the air filters other than HEPA:

Pleated Filters

The pleated filters are one of the most used filters, the filters are made of cloth or paper that are folded in a series of small pleats which are made with materials like polyester or nylon. Their construction increases the surface area which provides them the ability to capture more airborne contaminants. These filters can remove small particles that have a size between 1.0 and 3.0 microns. One of the main advantages of pleated filters is the ability to capture large particles as well as small particles which makes them a good choice for residential use.

Electrostatic Filters

The electrostatic air filters use static electricity that’s the reason these filters have this name, another name of these filters is electronic air filters. The mechanism of filtration of these filters is to attract airborne pollutants with the help of static electricity. The main benefit of these filters is that they come in reusable options which makes them cost-effective for long-term uses. You just need to use them once a month to make sure they are working properly.

Activated Carbon Filters

These filters are also known as activated charcoal filters because they use charcoal to remove contaminants from the air. These filters help you to remove VOCs (volatile organic compounds), which are toxic gasses that are released by some chemical home cleaners, newly polished furniture, etc. The activated carbon filters use a process called adsorption which means the airborne pollutants are stuck on the surface of the filter during the filtration process.

UV Light Filters

Filters that use UV-C light (short-wave ultraviolet light) to eliminate bacteria, mold, and other types of contaminants from the air are known as UV light filters. The filtration process of these filters is simple, when the air passes through the filter then the airborne particles get terminated due to the exposure to UV light. These filters are great for places where a sterile environment is needed.

Washable Filters

Air filters that are washable and used again and again are known as washable air filters. These filters are usually made of woven polypropylene media and they usually last for 5 to 10 years. Just remember these filters require a wash once a month and by doing this the efficiency of the washable filter stays optimal for a long time.

Pros And Cons Of Air Filters

Air Filter’s Type	Pros	Cons
HEPA Filters	Exceptional Filtration Efficiency Long Lifespan Create less Noise	High Cost High Airflow Resistance Not Supported By Every HVAC System
Pleated Filters	High Filtration Efficiency Long Lifespan Durable	High Cost High Airflow Resistance Not Supported By Every HVAC System
Electrostatic Filters	Cost-Effective Low Airflow Resistance Customizable	Low Lifespan Limited Filtration Efficiency Frequent Replacement
Activated Carbon Filters	Remove Odors And VOCs Support Most HVAC Systems Improve HVAC Lifespan	Limited Air Filtration Frequent Replacement High Cost
UV light Filters	Removes Germs And Pathogens Low Maintenance Prevent Mold Formation Inside HVAC System	High Cost Energy Consumption Limited Filtration Efficiency
Washable Filters	Cost-Effective Long Lifespan Eco-Friendly	Low Filtration Efficiency Regular Maintenance Frequency Not Supported By Every HVAC System

Benefits Of HEPA FIlters

After learning about HEPA filters and how they work you must be thinking are there any benefits to using a HEPA air filter? A simple answer to your query is yes using these filters can provide you with many benefits and some of these benefits can be life-saving. Yes, life-saving wanna know how? If yes here are some of the key benefits of using a HEPA filter:

Removes Harmful Contaminants

A HEA filter is specially designed to capture and eliminate particles of microscopic size that can affect you and your environment. Particles like pollen, pet dander, bacteria, mold spores, and many more are terminated by this filter. These filters have a dense network of fibers which makes them efficient at capturing particles of size 0.3 microns or less which ensures that your home is free of harmful contaminants.

Reduces Health Risks

Do you know that some of the airborne pollutants can cause severe health risks? If your answer is no then you should know that some airborne contaminants can cause health issues to children, elderly people, and those people who have respiratory problems. One of the key benefits of HEPA filters is that they remove pollutants that cause health risks and ensure that your home has a healthy environment.

Help With Allergies And Asthma

In recent years, health problems like pollen allergies and respiratory conditions like asthma have increased. A HEPA filter helps individuals to get relief from these issues caused by poor air quality by eliminating allergens like pollen, pet dander, and dust mites from the air. This provides you with an allergen-free home and allows individuals to breathe comfortably without triggering their asthma and allergy symptoms.

Improves Indoor Air Quality

As mentioned earlier the air inside your home is 2 to 5 times worse than the outside air and if you don’t fix this problem it can cause many issues to you and your home. The main benefit of a HEPA filter is that it captures almost every type of airborne particle and aerosol-released by-products that you use inside your home which improves indoor air quality and provides you benefits like good quality sleep, a less dusty home, and many more.

Downsides Of HEPA FIlters

As said by old people, everything in this world has benefits and downsides too, this goes the same for the HEPA filters. In the above section, you learned about the benefits of these filters like improving air quality, preventing health risks, and many more. In this section, you will learn about the downsides of HEPA filters, so here are some of the downsides:

Maintenance

One of the main downsides of HEPA filters is that they need proper maintenance to work efficiently. Users of these filters must change them every 12 to 18 months which can be a problem because you need to find a filter that fits properly to your HVAC system and even if you tackle this issue there are other things that you need to maintain. You should inspect these filters for damage every 1 to 3 months because sometimes these filters create air leaks due to damage.

Cost

HEPA filters provide you with highly efficient air filtration but that comes with a high price. These filters are pretty expensive. The price of these filters can range between hundred and thousand dollars which is very costly for many individuals. So people who want to purchase a HEPA filter should think many times and that makes it one of the main downsides of these filters.

Compatibility

Compatibility can be a problem with a HEPA filter because many HVAC units don’t support the airflow resistance that is caused by these filters. Airflow resistance means pressure put on air while passing through a medium like an air filter. HEPA filters create high airflow resistance which makes the HVAC unit work harder and that can cause problems for the unit.

Conclusion

The air quality is decreasing day by day in the outside world but the air that is inside your home is much worse and to fix this air filters are created. A HEPA filter is a type of air filter that helps individuals improve indoor air quality by eliminating 99.97% of airborne particles. There are other types of filters available such as pleated filters, electrostatic filters, UV light filters, and many more. HEPA filters come with many benefits like reducing harmful particles from the air in your home, helping individuals to relieve allergies and asthma, and reducing health risks that can be caused by some airborne pollutants. But every good thing comes with a downside and this is the same in the matter of HEPA filters.

These filters are pretty expensive because their price ranges from a few hundred to several thousand dollars. These filters have high prices because of their complex manufacturing and air filtration ability. Maintaining these filters can be challenging sometimes because you need to check them every one to three months for damages which can affect its filtering performance. Overall a HEPA filter is a great choice for commercial uses but you can also use them in residential places. Are you looking for an air filter that fulfills your filtration needs? Here at Custom Filters Direct, we are known for providing high-efficiency MERV-rated filters. To know more about us contact us at (877) 812-7983.

MERV 8 Air Filters

MERV 11 Air Filters

MERV 13 Air Filters

Frequently Asked Questions

Who Should Use HEPA Filters?

Individuals who want an environment that doesn’t have most of the types of airborne pollutants should use a HEPA filter. These filters are efficient at removing the smallest particles that other filters can’t provide. In places like laboratories where people work on chemicals that get affected by contaminants of air and require a sterile environment, these filters can be very helpful.

Why Are HEPA Filters At The Top?

The HEPA filters are at the top because of their ability to clear almost 99.97% of airborne contaminants and this feature is not provided by any other type of filter. With the help of these filters, individuals can eliminate particles of size 0.3 micrometers which is considered very small. These filters are efficient at clearing microorganisms such as bacteria and viruses. All of these features are the main reason that HEPA filters are at the top.

Should I Use A HEPA Filter In My Home?

The answer to this question depends on your requirement for air filtration. HEPA filters are efficient at providing extremely clean air and this kind of requirement is most of the time needed in laboratories and hospital-like places. So individuals who want to use HEPA filters should consider that they need extreme filtration or moderate. Most people require only moderate filtration because they don’t work on highly reactive substances and don’t require the sterile environment that is needed in hospitals.

How Often Should I Change My HEPA Filter?

The frequency of replacement of your HEPA filters depends on many factors but according to experts, you should change your filter every 6 months to a year. The time for replacement can also increase depending on the quality of your HEPA filter, and the condition of your house. For example, a high amount of dust in your house can make your filter dirty fast as a result you may need to replace it more often.

What Are HEPA Filters Made Of?

The HEPA filters are made of thin fiber which are arranged in layers. Usually, materials that are used to make these filters are polyester, polypropylene, or fiberglass. The design of these filters captures particles of different sizes because every layer of the fibers can eliminate particles of various sizes. Due to their complex construction, these filters are highly efficient at capturing small particles.

Can A HEPA Filter Damage My HVAC System?

Yes, a HEPA filter can damage your HVAC system and this can happen due to airflow resistance. The meaning of airflow resistance is pressure put on air while it is passing through the air filter. The HEPA filters have high airflow resistance which will make your HVAC unit work more and if this happens for a long time then the unit can get damaged if it is not able to support the required airflow resistance.

What Is A HEPA Filter?