摘要 |
The invention relates to an air filter unit (10) comprising at least one main air filter (1) and an additional air filter (2) which is connected to the main air filter (1) by means of an air line (3) and comprises at least one additional filter element. The additional filter element is formed, on the untreated air side of the main air filter (1), by an at least partially porous wall of the air line which is closed on the suction side. Conversely, when the additional filter element is applied to the treated air side, it is arranged inside the air line connected to the main air filter. |