More about HEPA and Carbon activated Filters

It is easy to see that the air inside your home is loaded with all kinds of things that can cause discomfort. Just take a look at where sunlight is coming through a window. Suspended in the air you will see dust, flooring fiber, dust mites, and even dead skin. Worse than what you do see is the stuff you do not; bacteria, viruses, microbes, and particles too fine to be seen. This is the stuff that will end up in your lungs and can make you sick.

Truth be told, it is not your fault, however. No matter how clean a home you keep, or steps you take, some dust is inevitable. Humans cannot help but shed millions of cells a day. You can, though, look into some type of air purifier to clean as much of this stuff as possible.

A HEPA (high efficiency particulate air filter) type air filter has become the most popular method of trapping the particles that get stirred up every time we walk across the floor or sit on the furniture. Most folks will use a HEPA filter as part of the exhaust on the vacuum cleaner, as the dense filtering material works to catch dust and assorted pollutants by two methods. This first is of course the interlocking of the media fibers, and they physically catch dust and larger stuff; they keep it from passing through. Second, the fibers are also “sticky.” So, if something is smaller than the holes in the media (if they were no holes, air could not pass through), it gets stuck when it comes in contact with the filtering media.

In order to qualify for a HEPA rating, the filter has to filter out 99.7% of all particles smaller than .3 microns in size. To give you an idea of that size, a human hair is 17 microns in size. Depending on the brand HEPA filters can last several years and do not require much maintenance. HEPA filters will actually work better after time because as more contaminants get trapped in the filter it is able to trap even finer particles. When purchasing an air purifier with a HEPA filter it is important to make sure the HEPA filter is true HEPA. Often time’s companies state their product has “HEPA-like” or “HEPA-style” filters which is not true HEPA. This means that the filter is not guaranteed to remove 99.7% of contaminants. A good HEPA filter should last at least a year and can even last up to 5 years depending on the brand.

No matter what type of air filter you ultimately decide to go with, make sure you understand the benefits and limitations of the machine. Certain types of filters are more effective at removing different contaminants. Like we discussed earlier, HEPA is the most effective at removing larger particles such as dust, dust mites, allergens, pet dander, bacteria, pollen and mold. However, if you are looking to remove odors, chemicals, gases and viruses you will need a filter that is specialized in trapping these small particles. The best filter to remove odors and gases is the carbon activated filter.

Activated carbon works by adsorption – the process by which a gas bonds to the surface of a solid. When air passes through the filter the chemical gases and odors will react with the carbon and effectively stick to it. The clean air then flows out of the system. Activated carbon works like a sponge and the more of it there is the more effectively it will work. Thus, it is important to find a purifier that comes with a respectable amount of carbon. Many systems carry 2lbs which is not enough to remove strong odors and gases and will not last very long. Systems that carry up to 15lbs of carbon will be very effective in removing these small particles and will last several years.

Since both of these filters do a job each other cannot do, it is often that they are used in conjunction. Many air purifiers carry both a HEPA and an activated carbon filter in the purifier so they can clean a wide range of contaminants. It is often times we will have problems with both odor and allergens and cannot bear to choose one purification method.

Read Next: What is HEPA Filtration?

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