The purpose of the evaporator is to condition the air in the vehicle passenger compartment. As air is blown across the surface of the evaporator fins, cold refrigerant flowing through the evaporator will remove heat and cool the air. As the air cools, moisture will condense into water on the fins lowering the humidity. The water will collect some of the dust and pollen filtering the air. Evaporators are made of aluminum to resist corrosion and are pressure tested at the factory.
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