A method for operating an HVAC system includes the steps of adjusting a heating temperature of a heat exchanger disposed in a first flow passage, directing a first partial air mass flow through the first flow passage, directing a second partial air mass flow through a second flow passage, and directing the first partial air mass flow and the second partial air mass flow downstream of the first flow passage and the second flow passage, wherein the heating temperature of the heat exchanger required to at least one of achieve and maintain a desired climate in the passenger compartment of the vehicle is set as a maximum heating temperature for the heat exchanger, and wherein only an amount of energy required to at least one of achieve and maintain a desired climate in the passenger compartment of the vehicle is added to the HVAC system.