AIR CONDITIONER FOR VEHICLE

摘要

PROBLEM TO BE SOLVED: To provide a heat pump type air conditioner for a vehicle which prevents or suppresses an outdoor heat exchanger from being frosted while heating inside of a cabin during energization by use of a plug-in connection so that excellent cabin heating is achieved during driving and a travel distance is extended.SOLUTION: An air conditioner for a vehicle comprises: an injection circuit 40 which splits coolant discharged from a radiator 4 to return the split coolant to the coolant that is being compressed by the compressor 2; and a controller which includes frost formation estimation means estimating frost formation on an outdoor heat exchanger 7. When performing a heating mode while electric power is supplied from an external power source to the compressor 2 or a battery supplying electric power to drive the compressor 2, gas injection into the compressor 2 is performed by the injection circuit 40 if frost formation on the outdoor heat exchanger 7 is predicted.