HVAC Heat Exchangers

Last update: 07 May. 2025

What is an HVAC Heat Exchanger?

Valeo is the leading thermal specialist among automotive Heating, Ventilation and Air-Conditioning (HVAC) system suppliers in Europe. There are 2 types of heat exhangers located in the HVAC unit: a heater core and an evaporator.

Evaporator:
In cold weather, the windows quickly fog up and it is essential to reduce the level of humidity in the cabin. The outside air is thus cooled as it passes through the evaporator. Some of the humidity in the air condenses on the fins of the evaporator. The condensates (water) are then evacuated under the car.
Fresh air is then blown into the cabin at temperatures between 2°C and 10°C with a lower humidity level, allowing optimum demisting.

Heater Core:
The heater core of an ICE vehicle uses engine coolant to increase the temperature in the passenger compartment. It demists and defrosts windscreens and windows.
The radiator core is located inside the Heating, Ventilation and Air-Conditioning system, after the evaporator.
In the case of an EV, the heater core can be replaced by an electrical air heater and/or surface electrical heaters.

Inner Condenser/Inner Evaporator:
The heat pump air conditioning system of an EV is provided with a compressor to which a front-end condenser and a inner condenser are connected through a three-way valve. The inner condenser is connected to an inner evaporator through an expansion valve. The air conditioning system further includes a control unit which defines a relationship among the heating needs, the workload of the compressor is varied, and the thermal operating condition of at least one of the inner evaporator and the inner condenser.