When you turn on the air conditioner (AC) in a car, several processes occur to provide you with cool, comfortable air inside the vehicle. Here's a general overview of what happens:
Compressor Activation: When you press the AC button or adjust the temperature dial to a cooler setting, the AC system is activated. The first component that starts working is the compressor, which is usually driven by the engine's accessory belt.
Refrigerant Circulation: The compressor takes low-pressure, low-temperature refrigerant gas from the evaporator and compresses it into a high-pressure, high-temperature gas. This process increases the energy of the refrigerant, raising its temperature.
Condensation: The high-pressure, high-temperature refrigerant gas is then pumped to the condenser, usually located in front of the car's radiator. The condenser's job is to release the heat absorbed from the cabin. As the hot refrigerant flows through the condenser coils, it cools down and condenses into a high-pressure liquid.
Expansion Valve or Orifice Tube: From the condenser, the high-pressure liquid refrigerant is passed through an expansion valve or orifice tube, depending on the car's AC system. This component reduces the pressure and temperature of the refrigerant, converting it back into a low-pressure, low-temperature liquid.
Evaporation: The low-pressure, low-temperature liquid refrigerant now enters the evaporator, which is usually located inside the car's cabin, behind the dashboard. Air from the cabin is blown over the evaporator's coils by the car's blower motor. As the warm air passes over the cold evaporator coils, heat is transferred from the air to the refrigerant, cooling the air.
Cooling the Cabin: The cooled air is then blown into the cabin through the car's vents, reducing the interior temperature and making you feel comfortable.
Heat Discharge: As the refrigerant absorbs heat from the cabin air, it evaporates and becomes a low-pressure gas again. The blower motor pushes this warm gas out of the cabin, and the cycle starts over again as the refrigerant goes back to the compressor to repeat the process.
This continuous cycle of compressing, condensing, expanding, and evaporating the refrigerant allows the AC system to remove heat from the cabin and keep you cool while driving. It's important to note that the car's engine powers the AC system, so it may slightly reduce fuel efficiency while it's running.