Unless you’re an aquarium hobbyist or own a water purification system that uses carbon, the idea of activated carbon in HEPA air purifiers probably seems strange to you. Even if the concept isn’t completely foreign, most still don’t know exactly what activated carbon actually does.

How Activated Carbon Is Used In HEPA Air Purifiers

Choosing HEPA air purifiers is often the first time most people encounter activated carbon. They begin their search because of allergies or asthma, but they have no real idea how these machines work. As they look deeper, they’ll start to learn that odors and chemicals are what’s actually causing the vast majority of the issues they’re trying to remedy. Most quality HEPA air purifiers are designed to eliminate allergens as well as odors and chemicals in the air. This is where the activated carbon comes in.

Activated Carbon Before HEPA Air Purifiers

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.

What The Word “Activated” Means

Most people have a general idea of what carbon is – it’s a mineral. The most basic example would probably be charcoal. Activated carbon is what you get after heat is used on the carbon to drive all of the impurities out, leaving room for more to take their place. Think of it as a sponge, only instead of using pressure to extract the contents, we’re using heat. Once the activated carbon is full, it can actually be reactivated by re-heating, though this is considered by most to be both impractical and dangerous. So, in this case, activated basically means empty.

Different Types Of Activated Carbon

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 absorbent characteristics are why activated carbon works so well filtering air and water both.

Harry writes articles about his HEPA air purifier, and HEPA air purifiers in general.