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 Is Active Carbon 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

Activated carbon has actually been around for quite a while, and though it sounds quite scientific, our ancestors have made good use of it for at least the last two centuries. Back then, they already knew of activated carbon’s extraordinary absorption qualities. In the early 1900’s, the stuff was produced and sold commercially in the form of a powder. At the time it was only used to remove color from sugar or taste or smell from water. Although we didn’t know it at the time, that was barely the tip of what this stuff is capable of. In World War I, the military discovered that they could use activated carbon in gas masks, filtering chemical agents from the air for the soldiers. The soldiers also used it for water purification, just like their ancestors. By this point, it was also available commercially as a granular form instead of just powder, which was when it began finding uses in even more situations.

What Activated Means

So, what is “activated” carbon, and is there such a thing as non-activated carbon? The heat used in “activating” the carbon drives the impurities out of the carbon itself, leaving places for the impurities of the water or air or whatever it is the carbon is filtering to reside. In a way, carbon can act sort of like a sponge, only instead of squeezing out its contents, one heats it out. Once the activated carbon is full, it can be reactivated by re-heating it, though this is considered to be impractical and dangerous. Non-activated carbon would basically be carbon that has stuff in it already, such as soot or charcoal.

Are There Different Types Of Activated Carbon?

Basically, yes. Though there are different types of activated carbon, and it’s often described in various ways, all activated carbon is nothing more than amorphous carbon-based materials. These materials all have many holes, also known as a high degree of porosity, which cover a relatively large surface area. This is what gives the material such awesome absorbent quality, enabling it to work so extremely well in filtering both air and water.

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