Air conditioning control apparatus for vehicles

An air conditioning control apparatus comprising:

• a duct having an upstream end and a downstream end, said upstream end including an internal air induction port and an external air induction port, said downstream end including a foot outlet, a defrost outlet, and a vent outlet;
• an air blower provided in said duct such that said air blower moves air through said duct from said upstream end to said downstream end, wherein the air enters said duct through at least one of said internal air induction port and said external air induction port;
• a heater core provided in said duct such that said heater core heats the air in said duct, wherein said heater core heats the air by using engine cooling water as a heat source;
• a foot outlet opening/closing mechanism provided at said foot outlet, wherein said foot outlet opening/closing mechanism opens and closes said foot outlet;
• a defrost outlet opening/closing mechanism provided at said defrost outlet, wherein said defrost outlet opening/closing mechanism opens and closes said defrost outlet;
• a vent outlet opening/closing mechanism provided at said vent outlet, wherein said vent outlet opening/closing mechanism opens and closes said vent outlet;
• said opening/closing mechanisms being capable of being arranged in a vent mode, wherein said vent outlet is open and said defrost outlet and said foot outlet are closed;
• said opening/closing mechanisms being capable of being arranged in a foot mode, wherein said foot outlet is open and said defrost outlet and said vent outlet are closed;
• said opening/closing mechanisms being capable of being arranged in a defrost mode, wherein said defrost outlet is open and said foot outlet and said vent outlet are closed;
• said opening/closing mechanisms being capable of being arranged in a bi-level mode, wherein said vent outlet and said foot outlet are open and said defrost outlet is closed;
• a first PTC heater provided in said duct downstream of said heater core, wherein said PTC heater is positioned such that said PTC heater can heat air flowing to said foot outlet and said defrost outlet;
• a second PTC heater provided in said foot outlet;
• and
• a control unit for determining a shortage of heat generated by said heater core, and for supplying electricity to said first PTC heater and said second PTC heater when said control unit determines a shortage of heat generated by said heater core and said opening/closing mechanisms are arranged in said foot mode, and for supplying electricity to only said first PTC heater when said control unit determines a shortage of heat generated by said heater core and said opening/closing mechanisms are arranged in said defrost mode.