Duct fans are designed to effectively remove air, moisture, unpleasant smells or acarus. They are used to support gravitational ventilation through a network of ventilation ducts that have a suitable diameter. Duct fans can effectively transport air from and into small rooms. Duct fans Dospel can be used both in public utility builidngs (shops, restaurants, pubs), sanitary rooms, residental premises, and industrial buildings (halls, warehouses, workshops, garages). Duct fans do not require frequent inspections, however not less that once a year. They are adjusted to the constant work. The advantage of Dospel's duct fans is that they are silent and highly efficient.