Thermal conditioning system for a motor vehicle

A thermal conditioning system for a motor vehicle, comprising a refrigerant circuit which is configured to circulate a refrigerant in a direction of travel, the refrigerant circuit including:

• a main loop including in succession in the direction of travel of the refrigerant:
• a compression device;
• a first heat exchanger which is configured to exchange heat with a first heat-exchange fluid;
• a first expansion device;
• a second heat exchanger which is configured to exchange heat with a flow of air (Fe) outside a passenger space of the motor vehicle;
• a second expansion device;
• a third heat exchanger which is configured to exchange heat with a flow of air inside the passenger space of the motor vehicle;
• a refrigerant accumulation device;
• a first bypass branch connecting a first connection point which is positioned on the main loop, and is between the second heat exchanger and the second expansion device, to a second connection point which is positioned on the main loop and is between the third heat exchanger and the refrigerant accumulation device, the first bypass branch including a first stop valve, wherein an inner volume of a portion of the main loop extending from an outlet of the first heat exchanger to an inlet of the first expansion device defines a first reference volume, wherein an inner volume of the refrigerant accumulation device defines a second reference volume, and wherein the ratio of the first reference volume and the second reference volume is greater than 0.2.