In a vapor-cycle cooling system, the role of the outflow valve is primarily to:

In a vapor-cycle cooling system, the outflow valve plays a critical role in regulating the pressure within the cabin. By controlling the outflow of air, the valve helps to maintain a stable and safe cabin pressure, which is essential for passenger comfort and the proper functioning of various systems on the aircraft.

When the outflow valve opens, it allows excess cabin air to be expelled, which in turn prevents pressure buildup. This ensures that the pressure in the cabin remains within designated limits, allowing the cooling system to operate effectively. Proper management of cabin pressure is especially important during different phases of flight, such as ascent and descent, where environmental changes can cause pressure fluctuations.

While temperature control and the introduction of outside air are important aspects of cabin atmosphere management, these functions are primarily handled by other components within the cooling system, not the outflow valve. Similarly, maintaining freon levels relates more to the overall refrigerant management within the system rather than the specific function of the outflow valve.