Evaporator Core: Description and Operation

Operation
In the evaporator, the incoming refrigerant expands and boils, taking up heat from the surrounding air. The cooled air is then led into the cabin.
The evaporator has fins and a refrigerant manifold. When heat is absorbed, condensation builds up on the outside of the evaporator. This condensation is drained out through a hose in the lower part of the evaporator casing and out into the engine compartment. The drain hose is required in order to protect against dirt and to prevent a higher noise level in the cab and to maintain cooling. In addition. odor may be generated if condensation is not satisfactorily removed.