What are Hepa Air Purifiers?  Obviously it’s a device that filters air, but what exactly does HEPA mean? HEPA stands for High Efficiency Particulate Arresting. These filters have been around for quite a while, though they’re only more recently seeing public use. Way back in the ’50’s, the United States government, or more specifically the Atomic Energy Commission had a need for something to remove the tiny radioactive particulates that are created in the process of creating atomic energy. Since that time, HEPA filter air purifiers have been using HEPA technology to clean the indoors in various situations, from beauty parlors to clean rooms. Allery and asthma doctors use HEPA air filters to help alleviate sufferers of allergies and asthma. But how does HEPA work, exactly?

To understand how HEPA air purifiers work, you have to have a good imagination, and at least a passable grip on physics.

Imagine particles floating through the air, all of different sizes. Sort of like how you can actually see dust particles when the sun bounces off them at the right angle. Now imagine a filter that doesn’t allow the larger particles through; only the tiniest. We’re talking particles so small that the human eye couldn’t hope to catch a glimpse of them. If a single sheet of this HEPA paper were placed in front of a fan that was constrained, such as in HEPA air purifiers, very little air would be able to pass through because of the tiny size of the holes. HEPA filter air purifiers made in such a way would need constant filter changes since the holes would be plugged quite rapidly. So, double the size of the sheed, and we’ll get twice the filter life and air flow. This only works to a degree, though, because you can only grow the sheet so large before it becomes completely impractical. Instead, HEPA air purifiers are built with these sheets folded back and forth on top of itself so that a very large surface area is presented to the airflow, and the HEPA air filteres are made far more efficient. This is very similar to how real-world HEPA filters are made in actual HEPA air purifiers. In some cases, there is as much as 40 square feet of filter material folded up in the HEPA section of a single filter. These sheets are constructed of either fiber, paper-like, or a polymer material, depending on the actual filter.

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