How Car Air Conditioner Works?

How Car Air Conditioner Works?

An Air Conditioner (AC) system in a car is similar to the AC system you have at the office or home. The Car Air Conditioner works with:

  • Compressor pumping vaporized refrigerant to the condenser
  • Condenser condensing and cooling the refrigerant
  • Receiver removing moisture from the refrigerant
  • Evaporator moving the cool air out
  • Expansion Valve reducing the pressure of the refrigerant

The primary purpose of the air conditioner is to cool down the temperature. Almost all the modern vehicles contain an air conditioning system and make your ride comfortable even in the scorching heat of summer. AC system in the car cools the air that is already present in the car. It doesn’t produce air. Now the question is how a car air conditioner works

Major Components of a Car Air Conditioning System

For a better understanding of how a car air conditioner works, it is essential to get familiarized with the basic components of the AC system. You can get an idea of how the AC system in cars works when you know the purpose of components.

  • Compressor
  • It is the heart of an AC system. As you can see from its name, it compresses the refrigerant from a gas into a liquid state. With the help of a drive belt, the compressor is then connected to a crankshaft. It is crucial to know that it draws power from the engine. So, whenever you turn on your car’s air conditioning system, the compressor pumps vaporized refrigerant to the condenser. 

  • Condenser  
  • The condenser is one of the most recognizable parts of the modern automotive AC system. Almost everybody knows that condensation results from the rapid cooling of warm air. Water vapors that are present in hot air are condensed to form a liquid state. The condenser looks like a radiator, and it is also positioned in front of a radiator. 

    Some people wonder why they have two radiators in their car. Let me clear; both are not the radiators. One is a radiator, and the second one is a condenser. The condenser is used to condense the high temperature and high pressure vaporized refrigerant that comes from the compressor. Air flows through the condenser and removes the heat from the refrigerant and cools it down. 

  • Receiver
  • It is another vital component, and its purpose is to prepare refrigerant for entry into the evaporator. It removes moisture from the refrigerant and acts as a reservoir. It is important to remove moisture from the refrigerant. Otherwise, it can result in crystal formation and lead to mechanical damage and blockage. 

  • Evaporator 
  • It is also an essential component of air conditioning system. It is the only component that is located inside the passenger compartment. All the other components are in the engine bay. The evaporator contains tubes and fins and looks like a radiator. Cold air from the receiver moves through the evaporator. When air circulates through the duct, it is blown past the core of the evaporator, and all the heat is released. Cold and dry air comes out from the AC vent. 

  • Expansion Valve 
  • The thermal expansion valve acts as a boundary between the high-pressure side of the system including the condenser, compressor, and receiver, and low-pressure side. It is clear by its name that it allows the expansion of refrigerant coming from the receiver-drier. In an expansion valve expansion takes place, so it reduces the pressure. 


    It is not among the components of the AC system. However, it is much-needed and lifeline of the system. If it’s not available, the heat won’t get out from the system, and you can’t enjoy the cooling comfort. When the temperature and pressure are low, refrigerant takes on a gaseous form. When temperature and pressure are high, it becomes liquid. 

    What is the Process of Cooling the Air in the AC System?

    Now, you have an idea of all the components of the AC system, so we will check how a car air conditioner works and cool the air. Let’s have a look at sequential steps for air cooling. 

    • The compressor compresses the refrigerant and converts it from gaseous to the liquid state. 
    • The pressurized liquid refrigerant circulates through the different tubes of the condenser. It allows the outside air to come in contact with liquid refrigerant. The liquid inside the condenser is high-temperature, so there is a temperature gradient between fresh air and liquid. The heat flows from the liquid to the fresh air. 
    • The refrigerant then moves to the receiver-drier. Accumulator or receiver contains desiccant to remove moisture from the refrigerant. It results in the formation of cooler refrigerant by still maintaining the system’s integrity. 
    • This cooler liquid refrigerant then flows into the expansion valve. It reduces the fluid pressure so that it can easily move to the evaporator. 
    • The low-pressure refrigerant then moves through the evaporator. Air that comes from the passenger compartment flows into the evaporator and blast through the evaporator core. Now, the refrigerant is cooled, and heat moves from air to refrigerant. Now, the air present in the evaporator is cold air. 
    • Fans allow the cool air to blow through the vents and cool the passenger compartment. At the same time, the system also reduces moisture from the evaporator airside. It allows the formation of dry air in the cabin. Meanwhile, the system collects and drains the condensate. Now the refrigerant in the system is in a liquid state, and it is hotter, and it converts into a gaseous state. 
    • Now, low-pressure gaseous refrigerant is ready to go back to the compressor, and the cycle begins again. 

    How Car Air Conditioner Works? The Complete Mechanism

    The AC system of the car doesn’t produce cold air. It takes the heat and moisture out of the air that is already in your car. Air left behind in the car is cooler. If you have a good understanding of all the above-mentioned air conditioner components, then you can easily understand the mechanism of how a car air conditioner works


    During the scorching heat of summer, no one wants to travel in a car that doesn’t have an AC system. AC system of a car works like AC of office or home. The car’s AC doesn’t produce air, and it takes air from the car, removes moisture and heat, and leaves behind cooler air. When the cabin is cool, you can enjoy a comfortable journey. This article is a helpful guide for those people who want to know how a car air conditioner works

    Efforts have been made to get the information as accurate and updated as possible. If you found any incorrect information with credible source, please send it via the contact us form
    Author: Sky Hoon
    He loved the future of self driving car and cannot wait for one. In the meantime, he loved to read up all about car and components like a computer.
    Read His Personal Blog
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