The ceiling grilles are intended for installation in industrial and commercia premises. They are suitable for tall premises (e.g. workshops, airports, theaters, bank halls) as well as for lower spaces with a height of more than 3,80 m (e.g. assembly workshops). The lamellas are adjustable and allow the creation of horizontal airflow under cooling and vertical flow in heating. The ceiling grilles are connected to the air ducts by means of a pressure box, which may be of a vertical or horizontal configuration.