Activated carbon filters are used in the last step of filtration. When air enters the box, the contaminant is absorbed and remains imprisoned there. The air can thus be recirculated in the room. The usual life expectancy of these filters is one year. The activated carbon filter can filter out odours.
Efficiency: 99.97% above 0.3 microns
Use: Chemical absorption of odours and certain contaminants (welding).