How effective is activated charcoal in air filtration?

How effective is activated charcoal in air filtration?

Using activated charcoal in air filtration processes is one of the most common and cheapest technologies. And yet, it has been proven to be a very effective one. Indeed, activated charcoals efficiently absorbs pollution in the air. Let’s see how activated charcoal works and its main advantages are.

How activated charcoal works when filtering air

Activated charcoal is a type of coal that has undergone a series of specific treatments aimed at increasing its absorption properties. Once treated, activated charcoal retains a lot more of the molecules that it come into contact with. Activated charcoal can retain both aqueous and gaseous allergens thanks to its very porous, highly reactive surface. Only one gram of activated charcoal is enough to absorb pollution particles present in an area of ​​400 to 2500 m².

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Activated charcoal typically comes in a cartridge or bag and is widely use in air filters. Depending on the cell diameter of the filter, it is also capable of trapping denser and thicker particles such as dust or hair.

How efficient is activated charcoal in filtering air?

As mentioned above, activated charcoal acts both on aqueous and gaseous components, making it ideal for broad use in air purification. Below is a list of applications where activated charcoal is used.

  • Elimination of allergens

Activated charcoal is a very common component in air purifier filters. It can serve to eliminate a wide range of pollutants present in the indoor air of a house, apartment or even office. Even higher-end ventilation systems are rarely enough to eliminate allergens from indoor air. Filters using activated charcoal filter can help you get rid of the most common allergens such as dust, pet hair, tobacco smoke, mites, pollen or even fungi. Depending on their density, some activated charcoal filters can also help remove from the air many chemical substances invisible to the naked eye such benzene, harmful gases and other volatile organic compounds contained in our sprays, cleaning products and cosmetics.

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  • Professional air purifiers and industrial filtration systems

Activated charcoal as a component in air filters has a wide range of application, including in the industrial world, hospitals, or the world of medical research. Ever since its invention, activated charcoal has been used in production plants across various domains. The fumes and vapors produced by the various machines are filtered by air purification systems with the help of activated charcoal which presents a great capacity of absorption of gases and impurities. Inexpensive yet devilishly effective, activated charcoal remains the most common component in air purification filters in the professional world.

Uses and benefits of activated charcoal air filters

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Activated charcoal serves numerous functions in air filters:

  • Anti-odour function: activated charcoal filters can be placed in bathrooms with too much moisture, in bedrooms, kitchens and even in refrigerators. This to help provide fresh and odour-free air throughout the entire house. Other examples include high-end cheese boxes or vacuum cleaners which sometimes come with activated charcoal filters.

  • Sanitation function: as part of larger air filtration system, activated charcoal can act on pollutants that vitiate the air. Exposure to fumes such as formaldehyde, styrene, benzene or charcoal dioxide is harmful and they must therefore be properly filtered out. The sanitation capacities of activated charcoal extend to mould, fungi and bacteria present in our homes or in labs and hospitals.

  • Purification function: Activated charcoal helps to break down allergens and fumes for sensitive people. Exposure to second-hand smoking can be greatly diminished by the simple use of air purifiers with activated charcoal. Purification is even more effective when combining several components and filtration layers.

Factors of effectiveness

The effectiveness of activated charcoal filters depends on several factors.

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The quality of the specific treatments they undergo varies a lot less than that of the materials used to source the coal. Whether it is from wood, coconut, marl, etc.

You also have to take its shape and density into account. It can come in several different forms such as powder, fibers or granules, extruded or milled charcoal. This combined with the different manufacturing steps will have a direct impact on the effectiveness of the final material in eliminating impurities.

The contact surface between the sucked in air and the charcoal is also a crucial factor. The larger the contact surface, aka the reactive surface, the more effective the air purification process will be. Unlike other purification processes such as ionization or UV purification, activated charcoal filters are not meant to be compact. The larger they are in a given air purifier, the more effective they will be.

Finally, the relative air humidity is also a decisive factor. That is because activated charcoal not only reacts with molecules in a gaseous state but also in the liquid state. So if the humidity in a room is too high, the activated charcoal will absorb a lot of water and lose its effectiveness. In such cases, it should be changed more often, or be used in association with an air dehumidification system.

Depending on the chosen air purification system, the activated charcoal filter should be cleaned or changed after several weeks, months or years. It remains one of the most affordable purification items.