Activated carbon is a granular charcoal material found in a range of air and water filtration products, cosmetics and supplements. This versatile material features a high porosity, meaning that one gram of activated carbon has an effective surface area equivalent to more than 1500 square feet. This is equal to the average size of a new home in 1973.
Keep in mind that when talking about the surface area of activated carbon in regards to filtration, we’re describing the ability of a surface to “grab” molecules or atoms found in the air or in liquids.
These molecules and atoms from the scents or tastes that we associate with odors we identify as being unpleasant. When these reach the olfactory nerve, we “smell” or “taste” the molecule. So how does carbon reduce odors?
How Carbon Filters Reduce Odors
Activated carbon air filters can reduce odors found in the air as a result of intermolecular forces that mediate how atoms and ions act on each other (attraction or repulsion). When molecules with a specific electrical charge reach the surface of carbon, that molecule will either bounce off and flow out of the filter or will attach to carbon and remain trapped.
Over a long enough period of time, the surface of carbon reaches capacity and is no longer able to attract new molecules. There are no visual indicators that a carbon air filter has passed its effective life; rather, smelling the air for new odors is the best indicator that it is time to replace the filter.
Types of Activated Carbon
Activated carbon is classified based on several criteria, including its preparation and application. These include:
- Powdered activated carbon
- Granular activated carbon
- Extruded activated carbon
- Bead activated carbon
- Impregnated carbon
- Polymer coated carbon
- Woven carbon
Granular activated carbon (GAC) is most commonly found in air and water filtration. This is the result of its larger particle size that presents a high contact area for smaller particles while helping to retain flow rates. So we know how it works, but is carbon good enough?
Find and Clean The Source of Odors
Running carbon air filters will help to reduce airborne odors, but they won’t prevent new odors for reoccurring and clogging the carbon material. To deal with odor problems and extend the life of carbon air filters, the first step is to identify the source of odors and clean them.
Nobody wants to hear that they should be cleaning more, but it’s the most effective measure against future odor problems. To make things a bit easier, we wrote a blog about the 11 Monthly Tasks For A Clean Home.
Follow the 11 steps we outlined in the blog above, and you’ll a cleaner, better smelling home!
When shopping for carbon air filters, consider purchasing a carbon pre-filter. These are installed behind the air filter on the intake side. A separate carbon filter may be ideal because the life of the air filter material and carbon can be different. Having two individual filters lets you control air quality without paying for new filters when they still have life in them.
Have you ever tried a carbon filter? Did it work? Let us know in the comments below.