Vehicle air conditioning system

A vehicle air conditioning system comprising:

• a duct configured to provide air to a vehicle cabin interior;
• a refrigerant evaporator disposed in the duct;
• an air conditioning cooling flow passage configured to provide cooled refrigerant to the refrigerant evaporator;
• a heater core disposed in the duct at a position downstream of the refrigerant evaporator;
• a heater hot fluid flow passage configured to provide hot fluid to the heater core;
• a heat exchanger configured to exchange heat between a refrigerant flowing in the air conditioning cooling flow passage and hot fluid flowing in the heater hot fluid flow passage;
• an electric heater that is disposed along the heater hot fluid flow passage in a position downstream of the heat exchanger and configured to further warm hot fluid that has undergone a heat exchange in the heat exchanger;
• an electrical component cooling flow passage configured to cool an electrical component installed in the vehicle by passing heat from the electrical component through a cabin exterior heat exchanger;
• a communication flow passage configured to connect the heater hot fluid flow passage and the electrical component cooling flow passage together such that the heater hot fluid flow passage and the electrical component are arranged in parallel, the communication flow passage including a first flow passage into which the hot fluid from the heater hot fluid flow passage flows and a second flow passage through which the hot fluid returns to the heater hot fluid flow passage, the first flow passage being connected to an inlet port of the cabin exterior heat exchanger, the second flow passage being connected to an outlet port of the cabin exterior heat exchanger;
• a fluid temperature sensor configured to detect a temperature of the hot fluid flowing in the heater hot fluid flow passage;
• and
• a flow passage selector valve that is disposed at a connecting portion between the heater hot fluid flow passage and the communication flow passage and configured to allow hot fluid flowing in the heater hot fluid flow passage to flow into the electrical component cooling flow passage when a temperature of the hot fluid detected by the fluid temperature sensor is higher than a prescribed temperature.