Audi Q5   Controls   Heating and cooling  3-zone deluxe automatic air conditioner
Switching on air conditioner
Press the OFF button, or
Press the AUTO button.
Switching off air conditioner
Press the OFF button to switch off the air conditioner and cut off the supply of fresh air from outside the vehicle.
The air conditioner will switch on again if you press the temperature control or one of the buttons.
Note
You can press the OFF button when the ignition is switched off to activate the "residual heat" function. The system will then heat the interior using the remaining heat in the engine coolant.