Activated carbon filter for Sirius S-DD2 120 (2pcs) cooker hood. Cooker hood in circulation mode: In this mode, the extracted air, passing through the grease filters, also passes through an activated carbon filter, which somewhat filters out unpleasant odors and vapors, and then the cleaned air is returned to the kitchen air . In this case, the capacity, depending on the state of the carbon filter (wear and tear), is approx. It drops to 60-80%. This mode of operation is only recommended if there is no outlet. Activated carbon filters must be replaced every 3-6 months, depending on use.