What is an Activated Carbon Charcoal Air Filter? How Does it Work?

In Brief: What is an activated carbon charcoal air filter?

Activated carbon (charcoal) air filters can remove harmful gaseous pollutants, odor, and VOCs (Volatile Organic Compounds) present in the atmosphere and improve the air quality. Activated carbon filters are the best for purifying VOC impurities. The filter consists of activated carbon (charcoal) in a powdered or granular form or honeycomb-like pattern.

There are several technologies for air purification available on the market today. Each has its pros and cons and is suited for certain circumstances.

If you are wondering if an air purifier with an activated carbon adsorption technique is right for you, in our article, we will address this in-depth, including its working, benefits, and in which situation it is best suited.

This article will help you decide whether you should choose activated carbon air purifier to solve your problem.

What is activated carbon charcoal air filter technology?

Activated Carbon filter technology uses filters or adsorption phenomena to remove the harmful gaseous contaminants like VOCs, NO2, CO2, etc present in the air and enhances the air quality. Adsorption is one of the preferred techniques as it does not produce by-products.

An activated carbon filter uses activated carbon to filter the gaseous impurities from the atmosphere.

Activated carbon is a form of carbon made up of materials with carbonaceous content.

These materials are subjected to carbonization (removal of non-carbon content) and activation (formation of pores) to create activated air.

Thus, we have activated carbon with small, low-volume pores and increased surface area suited for adsorption.

Now let us discuss the working of the activated carbon air filter. There are two techniques used in carbon air filters, the Adsorption method and the Filtration method.

Adsorption method – Adsorption is a surface-phenomena where the atoms, molecules and ions, adhere to the solid surface. Activated carbon is a universal adsorbent and is used in carbon air filters.

The activated carbon filter has bonding sites (pores) that trap the gases. The impurities found in these gases are removed by adsorption.

Thus, the gaseous impurities are removed from the atmosphere.

Filtration method – In this method, the contaminants from air or liquid are removed by forcing the air through the filters.

The filtration is done using several techniques, namely thermal oxidation, catalyst, regeneration, and reverse reactor.

Thermal oxidation – In this method, the air that flows through the filter is heated to a certain temperature.

It is then oxidized using thermal oxidizers to remove the VOC contaminants in the air. The filtering efficiency of this method is 99%.

Catalyst – In this method, the impure air is heated to 303ºF and then sent to a heat exchanger for further heat treatment.

It is then passed through a honeycomb-shaped catalysis bed where catalytic oxidation takes place and the impurities are eliminated.

The filtering efficiency of this method ranges from 90-95%.

Regeneration – In this method, the contaminants in the air are removed as it passes through the chamber containing shell on one side and activated carbon wrapped with Teflon on another side.

The activated carbon is regenerated by electrical heating in the presence of nitrogen gas.

The nitrogen gas is then purified by gas purifiers containing silica gel and mol.

Reverse reactor – In this method, the impure air that enters the filter is dried and sent to a pressure-controlled chamber. It is then sent to an adiabatic bed reactor where the filtration takes place.

These are some of the filtration techniques used in Activated carbon filters for eliminating the gaseous impurities.

I hope you would have gotten a clear image of the activated carbon air filter.

Benefits of activated carbon charcoal air filters

Now let us discuss some of the benefits of the activated carbon air filter.

Eliminates VOC – Activated carbon filters can remove chemical disinfectants, VOCs such as benzene, ethylene, glycol, etc, that are suspended in the air. It is one of the main benefits of carbon filters.

Low cost and easy maintenance – Activated carbon filters are of low cost compared to other filters and are easy to maintain.

Removes Odor – Activated carbon filter can eliminate any type of odor in the air and provides pure and fresh air to breathe in.

Improves Air Quality – An activated carbon filter removes dust, pollen, VOCs, and odor thus, improving the air quality.

Controls Humidity – Activated carbon filters control the humidity in the air.

Limitations activated carbon charcoal air filter

Pros and cons are the two sides of the same coin. Now let us discuss some of the limitations of the activated carbon air filter.

Poor filtration – Activated carbon filters cannot filter gaseous impurities like (sodium, nitrates, heavy metals, etc) that do not have a carbon content in them.

Ineffective against microbes – Activated carbon air filters are ineffective against microbes. To protect them from bacterial growth, the filter is traced with a small amount of silver.

These filters are called silver-impregnated activated carbon filters.

Short life-span – The filters in the air purifiers are short-lived. Once the binding site of the filter is filled with contaminants, it stops working and gets replaced.

Where to use Activated carbon Air Filters?

Now let us discuss some of the roles played by Ionizer air filter technology in our day-to-day life.

Home – Activated carbon air filters are used in the home to improve the air quality. It also removes the food odor, pet odor, cigarette odor, smoke, and other VOCs released by the commercial products.

Industries – Activated carbon filters are used in industries to remove unwanted compounds such as hydrogen sulphide, VOCs and reduce air pollution. It also eliminates the odor produced during the industrial process.

HVAC units – Activated carbon air filters play a role in many HVAC units. The amount of pollutants emitted by HVAC units is reduced to a considerable extent by these filters.

Car cabins – Activated carbon filters are used in car cabins to protect the car and passengers from impurities like dust, pollen, spores, bad odor and improve the air quality.

The filters are coated with an anti-bacterial coating and prevent the entry of bacteria into the cabinets.

It also keeps the A/C evaporator clean and allows it to cool at peak efficiency.


Thus, the Activated carbon air filter improves the air quality by removing the gaseous pollutants and foul odor from the atmosphere using adsorption and filtration techniques.

Now, you must have a good understanding of the Activated carbon charcoal air filter, its pros and cons, and its application in various fields from the above article.

In case of further information, please type in the comment box below or reach us through email.

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