What is activated carbon filter

Are you wondering what is an Activated Carbon filter?

Or how does an Activated Carbon filter work?

Well, you’re not alone.

This is one of the least understood types of filters on an air purifier.

Sometimes it’s also referred to as Activated Charcoal air filter, which adds to the confusion.

And with so many different air purifier filters to choose from these days, you may curious to find out how Activated Carbon filters work and what the benefits of using one.

In this article, we’ll explain everything you need to know about Activated Carbon filters and how it can help purify your indoor air.

By the time you’re done reading, you’ll know exactly why this feature is so important and why most of the top 10 air purifiers include it.

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What is Activated Carbon Filter?

Activated Carbon filters are made up of small bits of carbon (i.e. charcoal) that are processed in a granular or powdered form or woven into a honeycomb-like pattern.

The word “activated” refers to the carbon being specially treated so that it’s extremely porous.

In fact, it’s so permeable that 1 gram of activated carbon can have a total surface area of 500 m2 (5,400 sq ft) or more.

This massive surface area is what enables Activated Carbon filters to adsorb many more contaminants than traditional untreated carbon.

Surface adsorption is a chemical process where the adhesion of atoms, ions, or molecules from a gas, liquid, or dissolved solid sticks to a surface.

The more porous the activated carbon material is and the larger the filter size, the more contaminants the air filter can capture.

How Do Activated Carbon Filters Work?

An Activated Carbon filter work inside a home air purification system to remove gases, chemicals, and Volatile Organic Compounds (VOCs) from the air.

Polluted air enters into the filtration system and must pass through the active carbon material.

During this process, the chemical reaction of adsorption takes place to trap gas, liquid, and solid contaminants.

After the contaminated air flows through the Activated Carbon filter, it becomes purified and returns back into the room for you to breathe.

The adsorption process of Activated Carbon is what delivers cleaner, fresher smelling air indoors.

If an Activated Carbon filter is used in combination with a HEPA filter, the activated carbon material also works as a pre-filter.

As a pre-filter, larger solid particles like dust, hair, and dirt are trapped by the Activated Carbon filter and enable the HEPA filter to be more efficient and last longer.

HEPA filters are used to capture microscopic contaminants such as allergens, bacteria, smoke, pet dander, mold spores. The efficiency rate can be as high as trapping 99.97% of particles as small as 0.3 microns.

Are All Activated Carbon Filters the Same?

Activated Carbon filters are typically designed in two forms:

  • A thick honeycomb-like filter with activated carbon making up the bulk of the material.
  • A granular form placed into multiple small packets that make up the entire size of the filter.

Some Activated Carbon filters are also infused with other compounds to improve their air purification abilities. This includes elements like magnesium dioxide, copper oxide, potassium permanganate, or potassium iodide to remove specific chemicals such as formaldehyde, ethylene oxide, and ozone from the air.

Benefits of Activated Carbon Filters

When used in an air purification system, Activated Carbon filters can provide the following benefits:

  • Removal of dust, dirt, lint, and hair.
  • Reduce household odors from smoke, cleaning chemicals, and garbage.
  • Eliminate smells from mold spores.
  • Remove second hand smoke. (See our guide on the best air purifier for smokers.)
  • Get rid of toxic airborne chemicals and Volatile Organic Compounds (VOCs) like benzene and formaldehyde. (See our guide on the best chemical air purifier.)
  • Improve the quality of life for people with Multiple Chemical Sensitivity.
  • Reduce diaper pail odors. (See our guide on the best baby air purifier.)

Summary on Activated Carbon Filters

You know the answer to what is Activated Carbon filter and how do Activated Carbon filters work.

As you discovered, Activated Carbon filters are an important element for any air purification system, especially air purifiers.

These filters with specially treated charcoal material are very porous and highly adsorbent.

When used in conjunction with other filters like a HEPA filter, an Activated Carbon filter can remove a significant number of contaminants from the air.

And whether you choose a filter that’s designed with granulars, a powdered form, or woven into a honeycomb-like pattern, you can breathe cleaner air that’s less polluted with gases, chemicals, and Volatile Organic Compounds.

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About David Morrison

David is an Air Quality & Comfort Technician. He has expert knowledge on the technology and design of air purification, air conditioning, and heating systems. His main role is to write content that helps people get the most value out of their air purifiers, air conditioners, and heating units. (See Full Bio)