Learn How Car AC System Works?

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The car AC system is an essential component of a comfortable and enjoyable driving experience, especially during hot and humid weather.

Understanding how the AC system works can help car owners diagnose and fix problems, maintain proper performance, and maximize energy efficiency.

In this post, we will explore the science behind the Car AC system, its key components, and the refrigerant cycle that keeps you cool on the road.

Whether you are a car enthusiast or a regular driver, learning about your AC system can save you money and hassle in the long run.

Overview of the AC Cooling in Any Car

Overview of the AC Cooling in Any Car

The Thermodynamic process is responsible for maintaining your car’s interior temperature. Here, the pressure is at play and influences the interior temperature.

You merely have to switch the AC on, and the compressor will handle the additional job. However, it is more complex than it seems.

A car’s air conditioning system consists of a miniature replica of the standard air conditioner’s evaporator, compressor, condenser, expansion device, and fan, all of which are installed in the passenger compartment to provide air conditioning.

This air conditioning system is powered by the engine’s crankshaft and is controlled from the cockpit by pushing the button designated for this system.

Here, we discuss the general operation of automotive air conditioning. But first, let’s go into this so that you know the importance of on-time air conditioning repair in your automobile and how you can check and do it with its required components.

The Side with High Pressure in Car Ac System

All car air conditioning systems are closed loops with high- and low-pressure sides. Beginning with the high-pressure side, which connects the engine to the passenger compartment:


The refrigerant must first be prepared for the evaporator. As the liquid leaves the condenser, it passes through a small reservoir built into the line.

This receiver-dryer includes desiccants, which are water-attracting grains. You’ve seen packets of desiccants in medicines, where they perform the same function: attracting moisture from the air to keep new medicines dry and odor-free.

In the receiver-dryer, any water that has entered the system is eliminated. If the water is left to stay and develops ice crystals, it may cause harm to the air conditioning system.


Clean Condenser To Maintain Car AC Compressor

The condenser is a radiator and performs the same goal as the radiator in your car to transfer heat away from the system.

The refrigerant reaches the condenser from the compressor as a pressurized gas. Pressuring the gas and transporting it to the condenser generates heat, but air circulating through the condenser’s twisting tubes cools the refrigerant until it becomes a liquid once again.

Imagine steam cooling and condensing back into the water to get the concept. The liquid refrigerant is now high-pressure and almost ready to cool the automobile.


compressor - How Car AC System Works

The compressor is a pump operated by a belt linked to the engine’s crankshaft. The refrigerant is a low-pressure gas when it is drawn into the compressor.

Once gas enters the pump, the compressor lives true to its moniker. The belt powers the pump, pressuring the gas and expelling it to the condenser.

Compressors can only compress gases, not liquids. As we go through the system, you will see that there are additional components whose function is to catch any water that unintentionally enters the AC loop.

Now we are providing Car AC Compressor Repair in Dubai at cheap prices to our customers.

The Side Thermal Expansion Valve (TXV) with Low Pressure:

Here, the system transitions from the side with high pressure to the side with low pressure. If you touched this system component, you would feel the temperature shift from hot to cold.

From the receiver-dryer, the high-pressure liquid refrigerant runs via the expansion valve, where it is permitted to expand.

This expansion lowers the refrigerant’s pressure, allowing it to enter the evaporator. The valve detects pressure and controls the refrigerant flow, allowing the system to work stably; nevertheless, the valve’s moving components may occasionally wear out and need replacement.

Before the liquid reaches the evaporator, some cars feature an orifice tube instead of an expansion valve, but it performs the same function by enabling the refrigerant to expand and the pressure to drop.

The orifice tube has no moving components and enables refrigerant to flow consistently, although it may get blocked with debris over time.

A system with an orifice tube automatically regulates refrigerant flow to the evaporator by turning the air conditioning system on and off.


The evaporator is where the magic occurs. While all other system components are housed in the engine compartment, this component is often positioned in the passenger compartment above the footwall.

With its coil of tubes and fins, it resembles a radiator, but its purpose is to absorb heat rather than disperse it.

Because the refrigerant enters the evaporator coil as a chilly, low-pressure liquid at an optimal temperature of 32 degrees Fahrenheit or 0 degrees Celsius, you do not want any water in the system. The refrigerant does not freeze at this temperature, but its boiling point is very low.

The heat within the vehicle’s cabin is sufficient to cause the R-134a in the evaporator to boil and change back into a gas, much as water turns back into steam when heated. As a gas, refrigerant can absorb a great deal of heat.

The gas leaves the evaporator and the passenger compartment of the vehicle, carrying the heat with it.

A fan blowing over the outside evaporator coil supplies the passenger compartment with cold air.

The gaseous refrigerant next enters the compressor, where it is compressed, and the process is repeated.

If the system employs an orifice tube, an accumulator will be placed between the evaporator and the compressor.

Sometimes, an aperture tube allows too much refrigerant to enter the evaporator, and not all of it boils.

Since the compressor cannot compress the liquid, only gas, the accumulator prevents any extra liquid from entering the compressor.

In addition to removing humidity from the air, the evaporator helps you feel cool. Water in the air condenses on the evaporator coil, along with dirt, pollen, and other particles in the cabin’s air.

When you stop your vehicle and see water trickling below, condensation from the air conditioner’s evaporator is likely and nothing to be concerned about.

How Often Should Car Air Conditioning Be Serviced?

Maintaining a well-functioning A/C system is just as important as taking care of your vehicle’s paint or exhaust system as it adds value to your vehicle.

Refrigerant leaks are a common issue that can damage your compressor and evaporator, not to mention the environment.

One of the potential signs of this issue is when your AC isn’t blowing cold air as it should, and a malfunctioning fan can also prevent cool air from entering the cabin. Gaskets and o-rings within the AC unit can wear out over time.

Preventative maintenance is more common than full repairs or replacements. To determine if your AC unit requires a maintenance service, simply use it.

If the air stops being cold, it’s time to get it checked by a warranty-certified service provider or a Car AC repair Dubai.

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