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What Is a HEPA Air Filter?

a homeowner changing out a hepa filter

Studies show that the air inside our homes is often much more polluted than the air outside. That is why many people have started turning to air purifiers to help make the air in their home healthier. However, not all air filtration systems are the same. Some offer a much higher level of protection.

HEPA air purifiers offer one of the highest levels of protection available to homeowners. HEPA stands for “high efficiency particulate air,” and it indicates the product uses a certain type of air filter. For a product to say it is a HEPA air purifier or HEPA air filter, it must meet the standards set by the U.S. Department of Energy.

This means that anything labeled as a HEPA filter must remove at least 99.97% of particles from the air that are just 0.3 microns in diameter. A micron is a unit of measurement used to determine the size of some of the smallest objects. For comparison, a human hair is usually between 50 and 70 microns in diameter. This means a single strand of hair is about 200 times wider than the particles that HEPA filters trap.

Particles of this size are too tiny to see, but they are small enough for people to inhale. This includes tiny substances you might find in the air in your house like bacteria, dust, mold and pollen that can make people sick.

How Do HEPA Filters Work?

Different kinds of devices, such as air purifiers and vacuum cleaners use HEPA filters to remove contaminants from the air. A HEPA filter is a mat or fine mesh made of synthetic materials or glass fibers, which traps particles in its fibers as air flows through it. These types of filters use a few different methods to capture particles. One way they do this is by working kind of like a net. When air flows through the filter, some of the particles are too big to pass between the fibers in the filter and they get stuck.

Some other types of particles are too heavy to move quickly around the filter’s fibers, so they end up getting trapped in the filter. A final way that HEPA filters capture particles is related to extremely small particles (those that are smaller than 0.3 microns). These tiny particles weigh so little that they bounce around in the air in zigzag patterns. They are small enough to fit between the fibers in a HEPA filter, but they end up getting trapped in the fibers when they bounce into them.

A good way to figure out how efficient an air filter will be is to look at its MERV rating MERV stands for “Minimum Efficiency Reporting Values.” This rating system shows how good a filter is at trapping airborne particles that are between 0.3 and 10 microns in diameter. The higher the MERV rating, the better the filter is at trapping particles.

Typical filters that people often use with their air conditioning system have MERV ratings between 5 and 13. Filters with lower ratings capture some contaminants like dust, pollen and mold particles. However, they will not trap as many particles as a HEPA filter.

HEPA filters typically have a MERV rating between 17 and 20. This means these filters are better at purifying air. But it usually takes a higher powered motor to push air through HEPA filters because they are so dense. If you try to use one of these filters with an HVAC system that was not made to handle a HEPA filter, you may end up needing AC repair.

That is why it is best to contact a licensed heating and cooling specialist before using a HEPA filter. These professionals would be happy to answer any questions you have about air filters and air purifiers. Plus, they can install filters for you and set up a regular maintenance schedule to keep your system working well.

a white kitchen

HEPA Filter Types

In order for a product to be a HEPA filter, it must meet the standards set by the U.S. Department of Energy. This means that all filters that are truly HEPA filters remove at least 99.97% of 0.3 micron-sized particles from the air. These products sometimes have the label “True HEPA” or “Absolute HEPA” on them. True HEPA filters are also considered to be medical-grade quality.

There are other products on the market that might have the word “HEPA” on them. However, these filters do not meet government standards to be qualified as HEPA filters. Instead, they might have labels such as “HEPA Like,” “HEPA Style” or “HEPA Type” filters. This is a marketing tactic instead of a standardized classification for a product. These filters might remove some harmful toxins from the air, but they probably do not work as well as true HEPA filters.

If a product has one of these misleading labels, it is important to read the product description. If the label lists its MERV rating, it can help you understand how efficient the filter might actually be.

Even easier, you can contact an air conditioning and heating professional instead of trying to figure it out on your own. They have the expert knowledge and skills to explain the pros and cons of various kinds of filters. These specialists can help you decide which filter might work best in your home and can even advise you on ways to save on your heating bill.

a beige couch in a living room

Can You Wash a HEPA Filter?

While there are some types of filters that are washable, HEPA air filters generally should not be washed. In fact, rinsing or vacuuming these filters can often damage them instead of making them last longer.

However, there are other steps you can take to keep your air clean. For one, regularly clean your air purifier using a vacuum to remove dust from the outside of the vents. Also inspect the inside of the unit and use a dry, clean cloth to remove dust that has collected inside.

It is also important to check the filter once a month and replace it when it gets clogged. Clogged filters can lead to more serious issues, such as frozen coils. In general, HEPA filters typically need replacing about twice as often as regular air filters. This is because HEPA filters clean more contaminants from the air than regular filters, so they usually get clogged faster. Exactly how often you should change out your filters depends on a variety of factors, such as:

  • Whether you live in an area with a lot of dust, smoke or pollution
  • The size of your house
  • Whether you have pets or young children in the home

While it is not a good idea to wash your HEPA filter, there are some steps you can take to help it last longer.

How to Make Your HEPA Filter Last Longer

One way to prolong the life of a HEPA filter is to use a pre-filter when possible. A pre-filter can help block larger particles like pet hair before they reach (and clog up) the HEPA filter.

It is also important to keep windows and doors closed when you can. This will help reduce the amount of outdoor particles like pollen that your filter will have to deal with. Another way to cut down on the amount of particles that pass through your air purifier is to wash your curtains at least once a year. Dust can build up on your curtains and release irritants into the air. To clean up dust in other areas in your home, you can use a vacuum cleaner that has a HEPA filter.

During a regular AC maintenance check-up, a professional can give you other, specific tips on how to keep the air clean in your home.

ABC Can Advise You on the Best Air Filter for Your Home

We understand that you want to provide the best environment for your family. The professionals at ABC Home & Commercial Services have a thorough understanding of HVAC systems and the filters that run best with them. While we’re there, we can assess your system and find ways to make your HVAC system more efficient. We even have a filter delivery service, so you never have to worry about running out of filters again.

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