An air conditioning unit for a vehicle has a unit case enclosing a blower fan, a cooling heat exchanger (evaporator) and a heating heat exchanger (heater core), and defining therein an air conditioning passage for conveying air from the blower fan through the cooling heat exchanger and the heating heat exchanger, to an upper outlet opening. The air conditioning passage has an upstream passage section extending downward on a first side of the blower fan to convey the air from the blower fan downward, an intermediate passage section extending under the blower fan in a first direction from the first side to a second side of the blower fan, and a downstream passage section extending upward on the second side of the blower fan to the upper outlet opening for directing the air over the blower fan in a second direction, opposite to the first direction, from the second side toward the first side (toward the passenger compartment of the vehicle).