Structural element of a vehicle passenger compartment comprising a selective air distribution module

The beam has an air inlet (8) communicating with an opening in the component for discharging air. A set of air discharge openings (9, 9, 14, 14) ventilates corresponding zones of a passenger compartment, where the number of discharge openings is lower than number of air distribution openings. A set of air distribution modules (7, 7`) is supported by a casing of an air conditioning system.