Components of a Car Air Conditioning System: Types, Workings & More

Those who live in a humid region will understand how satisfying it is to get into a car and turn on the AC. Feeling that cold blast of air, especially on a hot summer day, is like bliss. However, read this blog if you have ever wondered how the components of a car air conditioning system carry out its work.

Here, we will discuss the process behind the air conditioning system in a car, its components and other related aspects

Before we jump into working on air conditioning in the car, you should know about its various components.

Compressor

A compressor in an AC compresses the refrigerant from its vapour form to get it into a liquid form. It then enables airflow in the system.

Condenser

This component reduces the temperature of the refrigerant by converting its state to liquid from gaseous. A condenser uses forced air to transfer heat.

Expansion Valve

An expansion valve transfers a low-temperature liquid refrigerant from the condenser. This valve works in two ways. First, it controls expansion and reduces pressure before sending it to the evaporator.

Evaporator

As the name implies, the liquid refrigerant takes heat and converts it into a gaseous form. In simple terms, this device evaporates that freezing liquid before it returns to the condenser. This process, involving continuous evaporation and condensation, repeats on a cycle.

Orifice Tube

The orifice tube looks like a cone that helps restrict the flow of a refrigerant. It converts the refrigerant from high-pressure liquid to low-pressure liquid mist before entering the evaporator.

Receiver Dryer

Sometimes when this liquid flows down to the compressor without converting into vapours, it can damage the compressor. Therefore, a receiver dryer is positioned strategically between the compressor and the evaporator. So if there is any remaining liquid, it can transform into vapour before entering the compressor.

AC Inline Filter

The purpose of this AC in-line filter is to trap the wreckage and emit only clean and fresh air. In a way, it purifies the air inside a car cabin.

AC Refrigerant

AC uses refrigerant as a heat exchange medium because of its low boiling point. When the refrigerant is at a higher temperature, it stays in its liquid form. However, when the pressure is reduced, it turns into its gaseous state.

Accumulator

The function of an accumulator is somewhat similar to that of a receiver drier. The only difference is that it works on a gaseous side of the AC loop. It has multiple purposes; one of its primary roles is to prevent compressor failure from liquid slugging. It also retains moisture and contaminants.

There are two types of AC systems in a car. They differ only on the basis of the position of certain components of a car air conditioning system.

1. Orifice Tube and Accumulator System

In the Orifice Tube and Accumulator system, the orifice tube is set before the evaporator. Hence, the position of an accumulator is before the compressor.

2. Expansion Valve and Receiver-Drier System

Similarly, the Expansion Valve and Receiver-Drier System has its expansion valve placed before an evaporator. The receiver-drier is put between a condenser and an in-line filter kit.

With a brief introduction to the components involved in a car AC system and its types, we can move on to understand how these processes work.

The AC in a car works by operating different states of a refrigerant. This manipulation between liquid and gaseous states makes all the changes. It is then that refrigerant absorbs the heat and humidity in a car and spreads dry air to cool the environment.

Here is the sequential process explaining how AC works in a car.

Step 1: This process begins with a compressor as it turns the low-pressure refrigerant to high pressure by heating it in the process.

Step 2: Now, this compressed liquid refrigerant passes through various tubes in the condenser.

Step 3: It then forces the gas to cool down with the help of a fan. Therefore, losing some heat during this process of turning into a high-pressure liquid form.

Step 4: The liquid refrigerant now flows through an expansion valve. It expands, reduces pressure, and further cools down on its way.

Step 5: This cold liquid now flows through an internal condenser that is also known as a cooling coil. Here it absorbs the heat of the cabin and evaporates into its gaseous state. 

Step 6: The cold air is pushed into the cabin with the help of a blower motor. It is then again compressed into a high-pressure gas and goes on as a cycle.

A car's air-conditioning system is operated under extreme pressure, which is why it needs to be sealed. If the refrigerant leaks or contaminants enter, the AC system can fail anytime.

Leakage in Any Component

Leakage in any of the components of a car AC system is common. Recharging the system with a new refrigerant is a temporary fix for this condition. After that, you must take your vehicle to a service centre and replace the faulty component. Once replaced, experts will clear the system and then recharge it again.

Overheating of a Compressor

Another common AC system failure can happen due to overheating of the compressor. If such a situation persists, the compressor can damage itself because it will try to operate with very little refrigerant. Furthermore, repairing a compressor is an expensive affair.

Exposure of a Condenser

The position of a condenser is right behind the vehicle grill to get a steady airflow. However, this makes it somewhat open and can be partially blocked by road debris and other contaminants. If this blockage occurs, the condenser can malfunction.

The components of a car air conditioning system can fail or develop some malfunctions in its internal parts at any time. After all, these are all machines, and they can falter at any given point in time. 

These are some reasons why regular inspection of your car's AC system is essential.  

• Regular inspection of a car's AC system can increase the lifespan of your car.
• It can also reduce the risks of compressor failure.
• AC inspection at every interval also means changing the air filter, thus helping you inhale purified air.

You should always look for these five signs to know when is the time to repair your car's AC system.

1. Not Ample Cooling

If you notice the AC is not cooling properly, there is a major fault. There can be multiple reasons for this malfunction. For example, there can be low refrigerant, a faulty condenser, or a damaged compressor.

2. More Moisture

If there is excess moisture in your car every time you turn on the AC, there is some issue behind it. This fault mainly occurs when debris or other contaminants block the condenser.

3. Unknown Noises

Strange noises coming from your car's AC are also a sign that it needs servicing. This can happen either if the lubricant used is not adaptable for that car model or cross-contamination of refrigerant. Also, sometimes when any of the components of a car air conditioning system breaks down, it creates weird noises in the AC system.

4. Visible Leakage

Leakages in any AC components are very risky because these can expose extremely harmful chemicals to the environment. If the refrigerant leaks, it can also damage your engine and result in more expensive repair work.

5. Foul Smell

Getting an unpleasant smell when your AC is on can probably be a reason if you have not used the AC in a long time. Bacteria can grow in the system, causing this foul smell. One way to avoid this is by using the AC in your car regularly.

Some believe you need to regularly recharge your car air conditioning system to keep them working correctly. However, this is not true. You only need to top off your AC system only if the components are faulty or there is any leakage. 

We hope you now know about all the components of a car air conditioning system along with its functions and working process by reading the above information. So, whenever you face any issues with your car's AC system, you can easily detect the problem and get it fixed.