Air Conditioning: Evaporator
The task of the evaporator is to cool and dry the air.
The refrigerant (the volume that is measured by the expansion valve) is sprayed into the evaporator. As soon as the refrigerant enters the cooling pipes, it evaporates due to the drop in pressure. During this process, heat is also extracted from the cooling pipes. The cooling pipes and the entire evaporator cool immediately. The refrigerant gas is then drawn out using the compressor.
The airflow is routed past the evaporator and is cooled and dried, and then forwarded to the passenger compartment via the air distribution ducts.
When the air entering the passenger compartment encounters the cold evaporator, the humidity in the air condenses on the evaporator. The water drains out under the vehicle via a drain hose. In the event of high humidity, this may be considerable quantities of water, which is often mistaken for a water leak from the engine for example.