| This guidance sheet forms part of a series of guidance sheets on preventing and managing offensive odours, and should be read in conjunction with EPA Victoria’s Odour Guidance for Industry webpage. |
Description
A carbon filter is placed within an exhaust/odour capture system that contains carbon, usually in the form of activated charcoal pellets which remove contaminants and impurities from filtered air.
Carbon filters vary in size and design, from a small filter for your home kitchen to large activated carbon packed beds. The charcoal pellets are treated to be porous to enable a large variety of pollutants, allergens, and other odour causing substances to be captured from the air.
Type of control
Physical filtration.
When you would use this?
Carbon filters are commonly used in residential homes and smaller businesses to remove odours or gaseous pollutants from sources such as tobacco or cooking smoke, paint fumes, and cleaning products. They can also be used in combination with other odour treatment systems such as bioscrubbers at larger sites.
Suitable for: generic odours, and other generic gaseous pollutants.
Industries that would use this: many industries could benefit from the inclusion of a carbon filter within their ventilation systems, odour capture systems, or exhausts as they are broad spectrum treatments.
Details and considerations
While carbon filters are a broad-spectrum solution to many odour risks, there are many things to keep in mind when using a carbon filter:
- If you process large volumes of odorous air, the frequency of replacement of filters may be cost prohibitive.
- Carbon filters cannot remove all fine particles such as mould, dust, or pollen from the air.
- A good maintenance routine will ensure you optimize odour removal performance of your carbon filter.
- The carbon within a carbon filter needs to be periodically changed to maintain optimum filtration, and to avoid moisture and particle build up clogging the system. It is important to understand the volume of air being filtered, and how this will affect carbon replacement.
- There is no clear way to determine whether your carbon needs changing. For some industries it may be smell, but this is not reliable. It is important to follow manufacturer’s directions to determine change frequency.
Carbon filters are commonly filled with activated charcoal/carbon. This means, the carbon inside the filters has been processed to form countless tiny/low volume pores which filter air and trap pollutants within.
The carbon filters air using the process of adsorption, where pollutants physically stick to the surface of the carbon. This is why activated carbon is used, as the pores created within the carbon result in a far greater surface area, allowing for more pollutants to be filtered before the carbon needs to be changed.
For specific filtration needs, activated carbon can be treated with different compounds to enable the adsorption of more complex or volatile pollutants.
Further information
Also see: metal mesh filters guidance sheet or metal sintered filters guidance sheet.