Abstract: A fan assembly (1) for an extractor hood to be used in a kitchen over a hob includes a body or casing (2) and an impeller (22) driven by an electric motor (20), with the casing having an internal cavity (4) which is bounded by a wall (3) and suitable to contain the impeller and the electric motor. The impeller (22) is located in the cavity (4) in such a manner as to define, with the wall of cavity, a spiral duct (25) for the vapours taken into the cavity, with the duct opening into a terminal outlet (5) and the casing (2) being open (at 8, 9) on opposite sides (6, 7) to favour the entry of vapours at the level of the impeller (22). The wall (3) of the casing includes a plurality of transversal portions having radii or radial configurations which differ from one another.

Abstract: A fan (1) for a smoke and/or vapor extraction system that includes an impeller (3) located within a diffuser or volute (2), the impeller (3) being driven by an electric motor (24); the impeller (3) having a body (20) having a flat part (21) from which a plurality of radially arranged blades (33) extend; these blades are separated from each other by a variable distance based on a periodic function. In addition to this, the diffuser (2) has an air delivery or discharge conduit (5) having a cross-section increasing from an inlet to its outlet (6).

Abstract: A fan (1) for a smoke and/or vapour extraction system that includes an impeller (3) located within a diffuser or volute (2), the impeller (3) being driven by an electric motor (24); the impeller (3) having a body (20) having a flat part (21) from which a plurality of radially arranged blades (33) extend; these blades are separated from each other by a variable distance based on a periodic function. In addition to this, the diffuser (2) has an air delivery or discharge conduit (5) having a cross-section increasing from an inlet to its outlet (6).