How Do Air Conditioning Systems Work in a Car?

Air Conditioning
Air Conditioning

When asked how automotive air conditioning systems operate, the majority of people would respond, “I don’t care how they function; I just want them to work! Even though it can be a typical answer, it does not address the query. If you’ve ever wondered how a car air con servicing system operates, keep reading for a closer examination of air-conditioner theory, system components, and system operation.

It is no secret that the use of air conditioning in cars is on the rise. With rising temperatures and increasing humidity, it has become increasingly important for people to have a comfortable place to relax while they’re driving.

In fact, according to The Guardian, car sales in Europe are forecasted to reach 47 million by 2020 due to this growing demand. And with AC not just being beneficial for drivers but also passengers, businesses are beginning to take notice too.

How Does the AC in a Car Work?

The car air con servicing by using the engine to create heat, which is then transferr through the air conditioning unit and into the car. This system uses three main principles: Expansion (cold air is forc into warm spaces), Condensation (sweat evaporates from the body and forms water droplets that can be cool down), and Evaporation (hot air turns to vapor). The refrigerant used in an automobile’s air conditioning system is switch between a liquid and a gaseous form to function. The refrigerant absorbs heat and moisture from the car when it changes states, enabling the system to release cool, dry air.

Refrigerants for HVAC systems

In the past, R-12 was the refrigerant utilised in vehicle air conditioning systems. A very efficient CFC-based (chlorofluorocarbon) refrigerant, R-12 (also known as Freon), is neither combustible nor toxic to people. The widespread use of R-12 was found by scientists in the late 1980s to be harming the ozone layer.

In the middle of the 1990s, manufacturers switched to R-134a. In contrast to R-12/Freon, R-134a is an HFC-based (hydrofluorocarbon) refrigerant that does not harm ozone. R-1234yf, the newest refrigerant, emits fewer greenhouse gases. R-1234yf is required in Europe, and it is anticipated that the United States will soon adopt it as the new standard.

Auto AC System Components:

The main parts of an automotive air conditioning system are few. The following are the primary components and what they do:

1.Compressor, which is mounted in front of the engine and is powered by a serpentine belt, is the system’s power unit that converts low-pressure gas into high-temperature, high-pressure gas.

  1. Condenser: Lowers temperature of refrigerant while maintaining high pressure; as refrigerant cools, it transitions from a gaseous to a liquid state; It uses forced air (fan or vehicle movement), similar to the engine radiator, to transfer heat. It is mounted in front of the car, beneath the grill.
  2. Dryer is mounted between the condenser and the metering device on the high-pressure side of the system. It has the following features:
  • Uses a desiccant (drying agent) to remove water from the refrigerant;
  • Has certain system-filtering properties;
  1. Metering Equipment
  • Fixed aperture tube or an expansion valve

Refrigerant is still in liquid form after leaving the metering device. It is mounted on the high-pressure side of the system, between the dryer and firewall. Lowering refrigerant pressure immediately lowers refrigerant temperature.

  1. Evaporator
  • In the evaporator, the refrigerant transforms back into a gas, producing a cooling effect.

As it passes over the evaporator, cabin air is cooled and drie. The only component is situated inside the passenger compartment, beneath the dashboar.

Route and properties of the refrigerant:

  1. Refrigerant with low temperature and low pressure enters the compressor (gas)
  2. The compressor releases high-temperature, high-pressure refrigerant (gas)
  3. While remaining under high pressure, the refrigerant cools and becomes liquid in the condenser.
  4. Water is remove from refrigerant by the receiver/dryer.
  5. Refrigerant pressure is decreas by the expansion valve.
  6. In the evaporator, refrigerant changes back to a gaseous state and absorbs heat, making the air that passes over the evaporator chilly and dry.
  7. A dryer collects the chilled and dry refrigerant, which is then sent to a storage tank or pipeline.
  8. Refrigerant is released from the storage tank or pipeline and enters the atmosphere where it evaporates.


The air conditioner uses pressure and temperature control to transition the refrigerant from a liquid to a gaseous form. To sum up, this is how a car’s AC system operates in general. The components of an air conditioning system are exactly the same as those found in an AC unit at home or office. However, if you have any doubts about what goes where and when, just refer to your vehicle’s owner manual for detailed instructions on how everything works together.


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