Difference Between HEPA and ULPA Filters

One of the decisions you will need to make in choosing an air cleaner is which air purifier filters to choose: a HEPA filter or an ULPA filter. Both of these technologies are effective but as you’ll see, there are some important differences with these two items.

Lets take a look at HEPA and ULPA filters to see which one is right for you…

true HEPA filter

What are HEPA Filters?

HEPA stands for High-Efficiency Particulate Air, and it is a designation used to describe a variety of filters that are able to trap at least 99.97% of all particles measuring 0.3 microns or larger. HEPA filters have a rich history (which we will describe below), and they are one of the most important inventions for air purification. They have a high efficiency and are very reliable.

Most HEPA filters are made of interwoven synthetic or glass fibers that are twisted and turned in many different directions to create a maze of fabric. As small particulates in the air go through this maze, they stick to the fibers and are trapped. As a result, they are removed and the indoor space has a higher air quality.

Particulates that pass through a HEPA filter are captured using a variety of methods. For some, they are trapped by direct impaction. This means that they travel in a straight path and are stuck when they come into contact with the fiber. Direct impaction is usually used to trap larger airborne particles, such as dust, mold spores, and pollen.

Sometimes sieving is used. Essentially, this is the process where particulate matter passes between two fibers and are stuck because they are not small enough to pass through. In this case, the particle becomes ensnared and is removed from the air.

In some cases, airflow is rerouted around the fibers. However, some particles maintain momentum and continue forward, colliding with the HEPA filter. Because of inertia, they do not flow with the air and are instead flung at the filter.

HEPA filters are excellent for removing a variety of particle sizes, but they usually cannot remove odors, gases or chemicals.

The solution for gas removal is to use a substance such as activated carbon. An air cleaner that has a combination of HEPA and activated carbon is a complete solution to remove many forms of indoor air pollution.


History of HEPA Filters

What do modern air purifiers and the development of the atomic bomb have in common? Not much, except for the presence HEPA filters.

HEPA air filters are considered by many to be a recent invention, but they date back to the mid 20th century. During World War II, the United States government commissioned the development of a massive bomb, what we now call the atomic bomb. This secret project, the Manhattan Project, needed advanced filtration methods to keep radioactive particles away from the researchers. HEPA filters were developed for this purpose, but they actually remained a classified technology until after the war was over.

The HEPA filter, once released for widespread use, then became a common source of air purification for commercial and healthcare facilities. They were primarily used in hospital rooms, pharmacy labs, and manufacturing centers. Aerospace engineering put HEPA filters to use, as did manufacturing facilities for computer chips.

In the 1950’s, the term HEPA was a registered trademark. However, the term is now used broadly to describe many different air filters that are highly efficient and effective.

Air filters have continued to evolve, becoming more efficient and more effective at trapping small particle sizes.


What are ULPA Filters?

Essentially, these are filters that are very similar to HEPA filters but are even more efficient at removing fine particulates from the air. While a HEPA filter removes 99.97% of particles down to .3 microns, a ULPA filter removes 99.999% of particles measuring down to .12 microns. So not only do ULPA filters remove more contaminants from the air, they also rated to remove finer particles from the air.


How are HEPA Filters and ULPA Filters Similar?

Despite their differences, HEPA and ULPA filters share a variety of similarities. Of course, both types of filters are used to filter microscopic particles, so they are not only useful in the home, they are useful for commercial applications as well. They can be used to essentially create an environment that has far superior air quality and can be a much healthier area for people who are vulnerable to health risks from air pollution. Even if someone is not particularly vulnerable to air pollution, both types of filters are useful.

One of the ways that they are similar is that they are useful in homes with people who are allergic to certain substances. For example, if you or someone in your family is allergic to seasonal pollen, a HEPA filter or a ULPA filter will meet your needs. Both have the capability to remove allergens from the air, creating a more comfortable and welcoming home.

The two filters can also be used for commercial applications because they filter a small particle size. If you have a business that needs advanced filtration, such as manufacturing or a business that works with chemicals, a HEPA filter or a ULPA filter may be able to meet your needs. This versatile capability makes both filters extremely popular, and it’s why they are found in both homes and businesses across the country.

The two filters are also similar in the way they clean the air. Both are made up of a material that allows air to pass through and traps airborne particles to improve indoor air quality.

Overall, the filter construction is another similarity, as both filters have a similar, although slightly different, construction. The air filtration process is the same, as both move air through a filter material that traps air pollution. Also, these two types of filters generally cannot remove gases and odors. In order to remove odors, you will need a different type of filter, such as an activated carbon filter. (More on carbon filters below.)


The Difference Between HEPA and ULPA Filters

Of course, the differences between HEPA and ULPA filters are numerous. The biggest difference is how efficient each filter is when it comes to removing air pollution.

A HEPA filter needs to be able to remove 99.97% of all particles 0.3 microns and larger. This is an incredibly small size; a typical human hair is roughly 75 microns and most allergens are larger than 1 micron. Therefore, a HEPA air filter is sufficient to solve air quality issues in a home or office.

An ULPA filter needs to remove airborne particles that are even smaller. In this case, the technology can remove a higher percentage of particles as small as .1 microns. This means they can be more effective in removing ultra-fine particulates.

To achieve the additional efficiency, ULPA filters have more filter media and a higher air flow resistance, also known as pressure drop. So, while an ULPA filter can do better with the smallest of airborne substances, they have less air flow so you will have less air changes per hour.

The price difference between these two filters can also be a factor. In general, you will find that ULPA filters are more expensive. This is one of the main advantages of HEPA filters, and it’s also one of the reasons that HEPA filters likely enjoy more widespread use.


When is a HEPA Filter the Best Option?

HEPA filters are likely the better option when you need to filter relatively larger particles, such as dust, pollen, mold spores and pet dander. While HEPA is known to filter fine particulate matter, ULPA filters can remove even smaller items from the air, but you may not need this advanced form of filtration from your home.

HEPA filters are also an ideal choice when you need a cost-effective option. HEPA filters have been developed for decades, and manufacturers have created highly effective ways to create these products, allowing them to sell for a bit cheaper. Also, HEPA filters contain less material, so it only makes sense that they would be more affordable.


When is a ULPA Filter the Best Option?

A ULPA filter, on the other hand, may be the best option if you are needing to filter extremely small particles such as in a clean room or certain manufacturing environments. ULPA filters can remove some of the most microscopic particles in the air. They are ideal for commercial and medical areas, and can also be used in residential homes that have people with allergies, asthma, or other respiratory conditions.

ULPA filters are also best if you are not on a tight budget and can achieve the air flow and noise level requirements for your space.


What Other Air Filters are Available?

We have talked a lot about HEPA and ULPA filters, but there are other options available. Activated carbon filters, for example, are an effective material for air filtration when you need to remove smoke or odors. These filters are made from carbon material like charcoal that has been processed to have a high amount of pores. These pores give the material a high surface space, which allows them to grab a lot of chemicals and air pollutants.


The Right Filter and Air Purifier is Waiting for You

If you are looking for top-quality air purifiers with excellent purifier filters and leading technology, including HEPA and activated carbon filters. We have a variety of air purifiers that can ensure cleaner, healthier air in your home by removing allergens, dust, pet dander, mold spores, and other forms of air pollution.

When you need high efficiency, one of the top options for your home is the EJ120 air purifier. This powerful air purifier uses a true HEPA filter and an advanced carbon filter to effectively clean larger spaces.

If you need air purification in a smaller space, consider the Max or the OV200 air cleaner, both are good options for your home.

From large offices to small bedrooms, we have the right air purifier for your specific space.
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