Air conditioning unit for a vehicle

A housing (1) defines an air passage having main passage (2) which branches into two separate passages (2a,2b) that lead air cooled by evaporator (3) in main passage or heated by heat exchanger (4) in main passage, to front and rear areas of the passenger compartment respectively. Control flaps (K1-K4) e.g. plate doors are provided to adjust an air flow from the evaporator and heat exchanger into the separate passage (2a).