Apparatus for exhausting dust (ventilation); Apparatus for exhausting fumes (ventilation); Apparatus for exhausting gases (ventilation); Apparatus for exhausting mists (ventilation); Apparatus for exhausting particles (ventilation); Apparatus for extracting dust (ventilation); Apparatus for extracting fumes (ventilation); Apparatus for extracting gases (ventilation); Apparatus for extracting mists (ventilation); Apparatus for extracting particles (ventilation); Industrial ventilation apparatus; Ventilation (air conditioning) installations for buildings; Ventilation (air conditioning) installations for laboratories; Ventilation apparatus; Ventilation grilles being parts of extractor fans