Final answer:
The condenser in an air conditioning system changes a high-pressure vapor into a high-pressure liquid through the process of condensation, facilitated by heat transfer to the surrounding environment.
Step-by-step explanation:
The condenser in an air conditioning system changes a high-pressure vapor to a high-pressure liquid. This is part of the refrigeration cycle where the electrically driven compressor elevates the temperature and pressure of the refrigerant gas and pushes it into the condenser coils. Inside the condenser coils, because the temperature of the gas is higher than the room temperature, heat is transferred to the room, and as a result, the gas condenses to a liquid. The liquid refrigerant then moves back through an expansion valve, which reduces its pressure before it returns to the outdoor evaporator coils, completing the cycle and preparing to absorb more heat from the indoor space.