Heat Pump Operation Heater Core
WARNING: This page is about a different car, the 2021 Audi S4 and 2021 Audi A4 Quattro. However, it is still accessible from the selected car via links, so may be relevant.
The gaseous or vaporous refrigerant that is compressed by the A/C compressor becomes a liquid in the heater core -A-. At the same time, the heat that is released is transferred to the coolant flowing by. Refer to Refrigerant Circuit .