Complete Guide to Carbon-Activated Filters

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Complete Guide to Carbon-Activated Filters

A car or truck is the driver's sanctuary, with comfortable seats, entertainment at the touch of a finger, and environmental controls to keep the temperature just right. When smoke, pollution, and other contaminants enter a vehicle through the air vents, the odour can ruin the experience for the driver and passengers. As an upgrade from standard paper air filters, carbon-activated filters work to naturally filter these contaminants, offering relief to the occupant's irritated eyes, nose, and throat.


How carbon-activated filters work

Also known as a charcoal air filter, a carbon-activated filter uses a two-step process to filter out dust, mould spores, dirt, pollen, and diesel particles measuring just a few microns across. The static electrical charge in the filter catches these particles before they have a chance to enter the car's passenger compartment. Activated carbon or charcoal saturates the filter to traps the odours, resulting in clean air passing into the vehicle's cabin.

Health effects

Pollen, dirt, and microorganisms that enter and remain in the car can affect the comfort and health of the occupants. Using a filter that prevents the contaminants from entering in the first place can help keep drivers and passengers healthy and alert. If allowed to persist, these contaminants can exceed the pollutants and particulates outside the vehicle by as much as six times.

Improved vehicle efficiency

A properly functioning carbon air filter also optimises the car's heat and air conditioning efficiency. When dirt and debris from the air and the road block the air intakes or air flow bonnet, the heater never gets warm enough and the air conditioning airflow is weak and lukewarm.


Particulate vs. carbon-activated filters

Particulate air filters contain a polyester layer that catches large dust and grit particles. They also feature a second layer that is electrostatically charged to trap and hold the smaller particles that make it through the first layer.

Carbon-activated filters feature another layer in addition to the paper and polyester layers in standard air filters. Surrounded by layers of nonwoven fibres, a layer of activated charcoal or carbon traps noxious odours, exhaust fumes, and other gases that would otherwise pass through the paper and polyester layers and into the passenger compartment. Carbon-activated filters are especially useful for those who spend a lot of time in congested traffic or dusty areas.

Adsorbing the fumes

Manufacturers treat the porous charcoal layer with chemicals and heat so that gases adhere to the surface. This process, called adsorption, differs from absorption in that the molecules, ions, or even atoms from any material stick to a surface instead of fluid being absorbed into a solid or liquid material. Some filters use natural ingredients, such as porous coconut shell-based activated carbon.


Choosing a carbon-activated filter

When selecting a carbon-activated filter, shoppers should note the year, make, model, and trim package of their vehicle. Because the filtering function relies on a tight, accurate fit to be effective, it is important that the filter fits the shopper's vehicle type. When installed, any padding around the housing edge should fit without gapping.



Installation instructions and procedures vary depending on the vehicle's year, make, and model. All air filters are located in the ventilation and air conditioning system on the receiving end of the fan. Many fan housings include an inspection door that the owner or mechanic can access to examine and replace the filter. Owners should refer to their car's manual for the location, schematic, and instructions. A professional auto shop can replace a charcoal filter in 15 minutes or less. Most filters are located under the bonnet, under the dash, or behind the glove compartment.


Care and maintenance

Once the carbon-activated filter is fitted in the car, the owner should note the odometer reading and date of installation. Typically, these filters need changing every 15,000 km or once a year for city drivers. Drivers who spend most of their time on unpaved, rural roads may need to change filters every six months or 7,000 km. If a filter becomes saturated, the passenger cabin may start to fill with pollutants.


How to buy carbon-activated filters on eBay

Carbon-activated filters are a simple and budget-friendly way to keep the air inside your car or truck clean and healthy. Once you have identified the right carbon-activated filter for your vehicle, simply enter the type of filter you need into the search box on any eBay page, such as "Ryco air filter" or "BMW charcoal filter" and browse the results. You may wish to pick up a few spares or buy in bulk so that you have replacements on hand to keep your car's interior environment clean and its heat and air conditioning systems running efficiently.

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