Evaporator Core: Description and Operation

EVAPORATOR
The evaporator cools and dehumidifies the air before the air enters the vehicle. High-pressure liquid refrigerant flows through the expansion valve into the low-pressure area of the evaporator. The heat in the air passing through the evaporator core is lost to the cooler surface of the core, thereby cooling the air.

As heat is lost between the air and the evaporator core surface, moisture in the vehicle condenses on the outside surface of the evaporator core and is drained off as water.

When the evaporator malfunctions, the trouble will show up as inadequate supply of cool air. The cause is typically a partially plugged core due to dirt, or malfunctioning blower motor.
The evaporator core with a laminate louver fin is a single-sides tank type where only one tank is provided under the core.