HEPA Air Purifiers Info

When picturing HEPA materials, you’re probably picturing something similar to an imaginary colander or screen. The materials in HEPA air purifiers actually do not look anything like that. Instead, they look like a very thin bail of fiberes, creating a veritible maze that the air has to find a route through, particle by particle. There are three different ways that HEPA filter air purifiers stop particulates. The easiest to understand is that a particle basically runs into a fiber and sticks. the second way is the particle getting within one diameter of a fiber in HEPA Air Purifiers and getting stuck on the fiber as it tries to skid by. Lastly, and the most complicated, is when very, very small particles (we’re talking 0.1 micron) travel in the gas flow, they sort of jump and juke due to the collisions with other molecules. This is called Brownian motion, and in itself can cause the molecules to be even more susceptible to the first two methods. To understand Brownian motion, picture bumper cars ramming into each other completely at random. Now picture the edges of the bumper car ring are actually sticky, or magnetic, holding the bumper cars to them. Now, to make things far more complicated, we’ll basically put edges all over the place so that the bumper cars have to navigate a treacherous maze. Only the other idiot bumper car drivers are still ramming each other, causing each other to get stuck, even if they would’ve skid through scot-free.

So you can see how HEPA air purifiers are capable of stopping bacteria, viruses, and mold spores, in addition to larger, more obvious items such as dust. For the most part, HEPA air filter purifiers can claim to be 99.97% efficient at removing the particles that are 0.3 microns from the air that passes through the HEPA air purifiers. The key word, though, is pass through. If the airflow doesn’t pass through the HEPA air purifieres, than it cannot be claimed. So, in essence, the claim of 99.97% is actually pretty inaccurate in those HEPA air purifiers that aren’t well designed, in which much of the airflow goes right around the HEPA air filters, and back into the room uncleaned. One series of HEPA air filters, the IQAir HealthPro series, is the only line that actually specifies that over 95% of air that enters their HEPA air purifiers goes through the actual HEPA filter.

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As good as HEPA air purifiers sound, they cannot remove gasses, chemicals, or odors. Consider that these are molecular level substances, and that the 0.3 micron holes are actually quite large compared to gas molecules. To compensate for this, most HepA air purifiers have some type of activated carbon based material that will absorb chemicals and odors. There are a number of different varieties of activated carbon that is included in most HEPA air filters. For example, the Air-O-Swiss unit has a thin mat in it to cancel out smells. In the Austin Air Purifier, there are pounds of activated carbon that do the same job. Regardless of the form, the carbon absorbs the gasses that would otherwise not be caught by HEPA air filters. These chemicals usually either cause unpleasant odors, or are possibly dangerous, harmful gasses.

Worth mentioning is the Blueair product line. The Blueair product line uses a different approach to HEPA. Not only do they provide a large surface area for air to pass through in their products, but they also have much larger openings in their filters, which are polymer based. This allows the Blueair to use a much smaller and less noisy fan and still achieve far more airflow. To compensate for this, these air purifiers use electrostatic brushes in the airflow just before the HEPA element. The result is that the pollution particles are charged electronically and end up getting stuck to the filter media, despite the larger passageway and increased air flow.

HEPA filter air purifiers are actually quite simple, in reality. A fan shoves airflow through a filter. As the same air passes back through the filter, it gets purer and purer. Therefore, the bigger the room, the bigger the product. Another approach, though, is more small air purifiers, which tend to work better. Think of a long, narrow room. If you put HEPA air purifiers at each end, the air only has to move half as far as if you were to put one larger purifier at one end, or even in the center. This results in cleaner air as not only does more air get treated, but the same air gets treated repeatedly, far more often than with just one of the HEPA air filters. Many times, the price is either comparable or better, and if a problem develops in one of your HEPA air filters, you only lose one and still have one small one in operation until you’re able to replace or repair the other.

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Activated carbon in HEPA air purifiers may seem strange to you, unless you own a water purification system which uses carbon or are an aquarium hobbyist. Even so, you may not understand exactly what it is activated carbon does.

For most people, though, the first time they encounter activated carbon will be in choosing HEPA air purifiers. Most customer begin their search for air purifiers due to asthma or allergies. As they learn more about HEPA air purifiers, though, they’ll learn that many of their respiratory problems come from chemicals and odors in the room. Therefore, most quality HEPA air purifiers are designed to address the chemicals and odors as well as the allergens themselves.

Believe it or not, humans were using activated carbon to purify water as many as two centuries ago. Even back then, we knew of activated carbon’s exceptional absorption qualities. It was not until the early 1900’s, though, that the stuff was produced in a form that could be sold commercially. Produced commercially, activated carbon was sold as powder. Back then, it was used only to remove smell or taste from water and to remove the color from sugar. As World War I got into full swing, we discovered that activated carbon could be used in gas masks to protect soldiers from chemical agents in the air. Not only that, but it was used for war time water and air purifying. At this point, instead of being used in powder for, it was used in a granular form. This was the beginning of activated carbon being used in many ways.

You’re probably wondering why we’re referring to this carbon as “activated.” Is there such a thing as non-activated carbon? Well, the heat used in “activating” the carbon is what drives out the impurities in the carbon itself. This leaves a place for the impurities in whatever it is the carbon is cleaning to reside. So activating carbon is kind of like emptying a sponge, only with head instead of pressure. After activated carbon becomes full, it can actually be reactivated by re-heating it. This is, however, not a good idea, and is considered dangerous and impractical. Non-activated carbon is basically charcoal or soot.

There are a variety of types of activated carbon, and it is described in a variety of ways, but generally activated carbon includes a wide range of amorphous carbon-based materials. These materials have a high degree of porosity (lots of holes) and a relatively large surface area. Basically, this means it has excellent absorbent characteristics. These absorbant characteristics are why activated carbon works so well filtering air and water both.

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