Final answer:
In an air conditioning system, the evaporator is the component where refrigerant changes from a liquid to a vapor as it boils from absorbing heat. The condenser is where the gas is turned back into a liquid after the compressor increases its temperature and pressure.
Step-by-step explanation:
The component of an air conditioning system where the refrigerant converts from a liquid to a vapor is called the evaporator. This process takes place because the refrigerant has a very low boiling point and when it receives heat from the cabin air, it starts to boil and changes into a gas. Conversely, the component of an air conditioner that converts gas back into liquid is the condenser. The electrically driven compressor increases the temperature and pressure of the refrigerant gas and sends it to the condenser coils, where it releases heat to the surroundings and condenses into a liquid. This liquid then passes through a pressure-reducing valve back to the evaporator coils, where it cools down as it expands and begins the cycle again.