A charcoal filter is a metal cylinder filled with active charcoal. This will filter the air going out of your grow room from the strong marijuana smell. A charcoal filter can be connected to the air extractor.
Learn all about climate for growing marijuana:
More climate related terms:
Climate | Air circulation | Airtight | Extractor | Fancontroler | Fans | Hygrometer | Humidistat | Humidifier | Dehumifier | Heating