A common EV thermal management system topology involves a compressor and heater working together in the same system by splitting responsibilities, as shown in Figure 2-1.

To cool the cabin, the refrigerant is first heavily compressed, turning it into a very high temperature gas. Then, refrigerant is cooled in the condenser, thus turning it into a liquid and warming the air in the process. Then, the liquid refrigerant enters the expansion valve, decreasing the pressure thus cooling the refrigerant. The refrigerant is then warmed in the evaporator, and the resulting cold air is blown throughout the cabin. When cooling the high voltage battery, a similar method is used, but the chiller is used as a heat exchanger to cool the coolant and transfer it to the battery to cool it.

The PTC is responsible for generating heat. This heat is then spread through the cabin via air from the blower. The pump helps coolant pass though the PTC, to then send to the high-voltage battery to warm it, as shown in Figure 2-2.