PF11000 11611801055 Filter Fan, 109 x 109mm, 18m³/h, 24 V dc. The filter fan has a new-to-the-market pleated fabric filter and louvre design that gives a high airflow at IP55. Its unique, patented water and dust pre-separation in the lamellas ensures that the majority of water and dust never reach the filter mat, extending its lifetime and therefore reducing the maintenance requirements.