One examples provides an automotive air-conditioning system provided with: a thermal unit having a condenser and an evaporator configured to be traversed by a refrigerant fluid and a hydraulic circuit, which is configured to be traversed by a carrier fluid and has a first portion provided with a first heat exchanger, a second portion provided with a second heat exchanger, a hot portion extending through the condenser, and a cold portion extending through the evaporator, a valve device being configured to connect selectively either the hot portion or the cold portion to the first portion and the second portion.