KDCF00B Carbon Filter for Rangehood models KCRHSCK90 and RHSCK91. The internal Kleenmaid Activated Charcoal (or “Carbon”) Filter is used on a rangehood installed in recirculating mode i.e. not vented outdoors. There is a charcoal filter located inside each of these rangehood models, which removes cooking odours from the air. They cannot be cleaned and will require replacement. The effective life of the filters depends on the type and amount of cooking you do. Generally the life of these filters is approximately six months, however always replace the filters when they no longer absorbs odours effectively.