What happens to freon in the evaporator of a vapor-cycle cooling system?

In the evaporator of a vapor-cycle cooling system, the freon (refrigerant) undergoes a critical phase change where it absorbs heat from the cabin air and vaporizes. This process is essential for the functioning of the cooling system. As the freon flows through the evaporator coils, it is exposed to warm air circulating in the cabin. The heat from this air is transferred to the refrigerant, causing it to absorb energy and transition from a liquid state to a gaseous state.

This phase change is crucial because it effectively removes heat from the cabin, resulting in a cooler atmosphere. The increasing temperature of the cabin air causes the freon to vaporize, allowing the cooling system to maintain a comfortable environment for passengers. This process directly ties into the principles of thermodynamics where heat absorption leads to changes in state, making it vital for efficient temperature control in aviation settings.