- Electric fan capable of generating a pressure differential between a first zone, named upper pressure zone, and a second zone, named lower pressure zone, the pressure of said upper pressure zone being greater than the pressure of said lower pressure zone, said fan comprising: - a stator; - a ventilation rotor rotationally mounted relative to the stator, said ventilation rotor being capable of generating a pressure differential between the upper pressure zone and the lower pressure zone; - a drive device for driving the ventilation rotor, said device comprising: • an electric motor adapted to be able to rotate the ventilation rotor relative to the stator; • a casing having a wall delimiting an internal space of the casing, said casing being disposed in said upper pressure zone; • an electronic device, said electronic device being disposed in said internal space of the casing, wherein the stator comprises a chassis supporting the ventilation rotor and the drive device and comprising: - a main support disposed in the lower pressure zone; - at least one arm (33a, 33b) rigidly connected to the casing and the main support, wherein each arm comprises at least one duct, named aeration duct, outside the casing and comprising at least: - one opening, named first opening, disposed in the upper pressure zone in the vicinity of an outer face of the wall of said casing; - one opening, named second opening, disposed in the lower pressure zone; and, - an opening, named air inlet opening, emerging into the upper pressure zone, characterised in that it comprises at least one air guide mounted on an outer face of the wall of the casing, said air guide forming, with the casing, a passage along part of the outer face of the wall of said casing between a first opening at a first end of the air guide and a second opening at a second end of the air guide, said second opening being disposed facing the air inlet opening of an arm comprising an aeration duct; and, said air guide being arranged to guide an air flow along a portion of the outer face of the wall of the casing up to the second opening of the air guide. - a stator; - a ventilation rotor rotationally mounted relative to the stator, said ventilation rotor being capable of generating a pressure differential between the upper pressure zone and the lower pressure zone; - a drive device for driving the ventilation rotor, said device comprising: • an electric motor adapted to be able to rotate the ventilation rotor relative to the stator; • a casing having a wall delimiting an internal space of the casing, said casing being disposed in said upper pressure zone; • an electronic device, said electronic device being disposed in said internal space of the casing, • an electric motor adapted to be able to rotate the ventilation rotor relative to the stator; • a casing having a wall delimiting an internal space of the casing, said casing being disposed in said upper pressure zone; • an electronic device, said electronic device being disposed in said internal space of the casing, - a main support disposed in the lower pressure zone; - at least one arm (33a, 33b) rigidly connected to the casing and the main support, - one opening, named first opening, disposed in the upper pressure zone in the vicinity of an outer face of the wall of said casing; - one opening, named second opening, disposed in the lower pressure zone; and, - an opening, named air inlet opening, emerging into the upper pressure zone,