LEMON Manuals: Even more car manuals for everyone: 1960-2025
Home >> Audi >> 2021 >> A4 Quattro Premium Plus, 2.0L Eng VIN B >> Repair and Diagnosis >> Heating, Ventilation & A/C (HVAC) >> A/C Compressor >> Air Conditioning (Refrigerant R134A Servicing) (2 Of 2) >> 87 Air Conditioning >> Refrigerant Circuit General Information >> Refrigerant Circuit Components Allocation, High And Low Pressure Sides >> Evaporator

Refrigerant Circuit Components Allocation, High And Low Pressure Sides: Evaporator

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

NOTE:

Two versions of evaporator are described.

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

The fluid refrigerant evaporates in the evaporator line coils. The heat required for this is extracted from the air flowing on the evaporator ribbing. The air cools off. Refrigerant evaporates and is extracted with the absorbed heat by the A/C compressor.

Fig 1: Evaporator
GWWV87-0935Courtesy of AUDI OF AMERICA, LLC

A defined amount of refrigerant is supplied to the evaporator by a restrictor or expansion valve. In systems with expansion valve, the throughput is regulated so that only gaseous refrigerant escapes the evaporator outlet.

Evaporator/High Voltage Battery Heat Exchanger (Chiller)

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

Fig 2: 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 throughput of the refrigerant (for example the coolant) is regulated so that only gaseous refrigerant escapes the evaporator outlet. Refer to Refrigerant Circuit .