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Home >> Audi >> 2021 >> A4 Quattro Premium Plus, 2.0L Eng VIN B >> Repair and Diagnosis >> Heating, Ventilation & A/C (HVAC) >> HVAC Control Systems >> Air Conditioning (Refrigerant R1234YF Servicing) (2 Of 2) >> 87 Air Conditioning >> Refrigerant Circuit >> General Description - Refrigerant Circuit Components >> Evaporator

General Description - Refrigerant Circuit Components: Evaporator

The evaporator is available in different versions. Depending on the design and the function, the heat energy of the flowing air needed (for example, an evaporator in the heater and A/C Unit or in the battery cooling module) or flowing coolant needed (for example near the high-voltage battery heat exchanger) is extracted for refrigerant evaporation. Refer to Refrigerant Circuit .

NOTE:

Two versions of the evaporator are described.

Evaporator in the Heater and A/C Unit (or in the Battery Cooling Module)

Evaporator/High-Voltage Battery Heat Exchanger (Chiller)

The liquid refrigerant evaporates in the evaporator (heat exchanger). The heat required for this is extracted from the flowing coolant in the evaporator. The coolant cools, the refrigerant evaporates and is extracted with the absorbed heat by the A/C compressor.

Fig 1: Identifying Liquid Refrigerant Evaporates In Evaporator (Heat Exchanger)
GWWA87-11578Courtesy of AUDI OF AMERICA, LLC

A defined amount of refrigerant is supplied to the evaporator by a restrictor (or expansion valve) and a shut off valve. The flow rate of the refrigerant (or the coolant) is regulated so that only gaseous refrigerant escapes the evaporator outlet. Refer to Refrigerant Circuit .