Electric fan unit including a casing defining a passage for an air flow and comprising a central support; a fan mounted rotatably on the central support; a shutter comprising a system of slats movable between a configuration in which the passage is completely open and a configuration in which it is completely closed, and a centrifugal regulator having a base element connected in rotation to the fan; an axially movable actuating memberconnected for operation to the system of slats in order to move them towards their maximum opening configuration when the fan is activated; at least two articulated arms connecting the actuator member to the base elementand movable by centrifugal force in such a way as to cause the axial advance of the actuating member; and a slidable couplingfor guiding the axial translational movement of the actuating member relative to the base element. The fan is mounted rotatably on axle connected fixedly to the central support; the axle defines the axis of rotation (z) of the fan and has a through cavity within which a rotating shaft is coaxially housed, a front end of this shaft being connected fixedly to said fan, while a rear end of the shaft is connected integrally to the base element of the centrifugal regulator. The base element is mounted rotatably on the axle, on the opposite side of the central support from the fan.