RC4/8 carbon

In Australia the finest carbon is mined from rare millions of years old deposits, activated 3 times and then sieved to the exact size suitable for air filters. This is RC4/8 carbon. There are many types and sources of activated carbon, but only Phesh Filters has access to this quality and sice RC4/8 carbon.

RC4/8 is a lightweight carbon with a very large surface area: one gram of activated carbon has a surface area of 1030 m2! The surface structure of the RC4/8 carbon makes it ideally suitable for adsobing large organic particles.

Phresh Carbon filters

Iodine number
Surface area
Fixed carbon
Volatile content
Total ash content
Inherent moisture
Apparent density
1030 mg/g
1030 m2/g
< 90%
< 0,5%


Phresh Filters are light weight filters. This is not only due to the light weight carbon but also to the aluminum flange and base

The carbon bed is machine compacted. Using very intense vibrations when filling the filter with the carbon the filter is filled to the max. So no air leaks or shifting carbon inside your filter.

Immediately after production the Phresh filter is bagged and sealed to preserve all the good qualities during transport.

Each Phresh Filter comes with two outer filters, which can be easily mounted around the filter with a Velcro seam. We supply two filters so you can replace the outer filter regularly and can wash the dirty filter at your own convenience.We recommend to change and clean the filter 2-4 times a year, depending on the level of saturation.

To easily connect ducting we supply 4 ducting clips. It is sometimes very hard to keep the ducting on the flange when you install it, especially when for example you are working in confined spaces ot high over your head. With the ducting clips installed on the flange, the ducting will not slide back from the flange, enabling you to connect it easier. Especially when you install insulated ducting this can be a real time saver. If you use single ducting we recommend to tape the ducting when using the clips, as they penetrate the ducting.


We recommend to install the filter in the highest area of your room.

- Keep humidity below 75% at all times to prevent reduced adsorption and reduced life time.
- Keep the outer filter clean: a clogged filter will create a pressure drop, diminishing the capacity of your extraction system.
-  Prevent bends and corners in your flexible ducting and always stretch it out to assure optimal airflow.

Phresh filters are designed to be used with flexible ducting. It is not recommended nor neccessary to connect the filter directly to the fan. This will cause more noise in your filter. We recommend to always use some flexible ducting (preferably insultated flexible ducting) between your fan and your filter to reduce fan noise in


The only maintenance you need to do is keep the outer filter clean. When changing the outer filter you can use a soft brush to clean the mesh.

In any case keep the humidity below 75%.