Refrigerant Circuit Pressures and Temperatures

WARNING: This page does not describe the selected car, but rather 17 other vehicles, including the 2009 Audi S4, 2009 Audi A4, 2008 Audi S4, 2008 Audi RS 4, and 2008 Audi A4. However, it is still accessible from the selected car via links, so may be relevant.

CAUTION:

When working on the refrigerant circuit, observe generally valid safety precautions and pressure vessel regulations.

The pressures and temperatures in the refrigerant circuit depend on the instantaneous operating statuses (e.g. engine speed, coolant fan speed 1, 2, or 3, engine temperature, compressor on or off) as well as environmental influences (e.g. ambient temperature, humidity, required cooling output).

On vehicles with A/C Compressor Regulator Valve N280 the pressure on the low pressure side is altered by actuating the valve.

For this reason, the values given in the following table are only intended as a rough guide. They are attained at an engine speed of 1500 to 2000 rpm and an ambient temperature of 20 C after about 20 minutes.

Refer to vehicle-specific refrigerant circuit for locations of pressure gauge connections → 87 - Air conditioning .

At 20 C with the engine not running, the pressure in the refrigerant circuit is 4.7 bar. Refer to → Air Conditioning System Principles

NOTE:

Pressure is measured in different units: 1 MPa (mega pascal) corresponds to 10 bar positive pressure or 145 psi, 1 bar absolute pressure corresponds to 0 bar positive pressure and thus to the ambient pressure (atmospheric pressure).