Evaporator Core: Description and Operation

The A/C evaporator core is the plate/fin type with a unique refrigerant flow path.
- A mixture of refrigerant and oil exits the Thermostatic Expansion Valve (TXV) and enters the evaporator tank area through the 1/2 inch (12.7 mm) tube.
- The tank area is divided into three sections: front inlet, front outlet and rear tank.
- The refrigerant enters the evaporator core tank area at the front inlet, flows down through the core and up the back side in a "U-flow" pattern.
- The refrigerant moves into the rear tank area and across to the other half of the core. The refrigerant moves down through the core and back up the front side of the core to the front outlet tank area.
- The refrigerant at this point is in a gaseous state. It exits the evaporator through the 5/8 inch (15.9 mm) tube then passes through the TXV.