Air conditioning system for automotive vehicles

An air conditioning system for an automotive vehicle has high heating power and includes an intake duct (1) formed with a port (8), a blower unit (2) for drawing air from a vehicle compartment via the intake duct (1), and an air conditioning unit (3) including a heater core (17) utilizing engine coolant as a heat source thereof for heating air from the blower unit (2). The air conditioning unit (3) can be disposed below a vehicle floor, whilst the intake duct (1) is disposed above the vehicle floor. Further, an electric heater (9) is disposed within the intake duct (1), as an auxiliary heat source.