An air conditioning system for a vehicle is provided. The air conditioning system includes a cooling module having a cooling duct and an evaporator core, and a heating module having a heating duct and an inner condenser. Additionally, an outer condenser is disposed extraneous to the heating duct, and a blower forms air flow in the cooling duct or the heating duct. The inner condenser, the outer condenser and the evaporator core are connected via a single refrigerant passage.