Beat the Heat: Discover How to Recharge Your AC

AC is a critical component that needs to be understood more by car owners. All modern vehicles incorporate this intricate system which must be maintained regularly as part of a well-serviced vehicle.

First, however, it is essential to understand precisely where AC units come from and how they function. Understanding them fundamentally will allow car owners to appreciate exactly why they must be maintained diligently for the best driving experience. 

Why Do We Need AC

AC units are one of those many luxuries we could not imagine living without. They are critical for those in the summer months and warmer climates, which make long journeys bearable. 

The air management system also offers a heating option. This more simple yet critical vehicle component allows occupants to tolerate blisteringly cold weather on an essential road trip.

This element of the vent system engages a fan and a heating element which will push hot air into the cabin. Again, it is a simple and effective system that performs its job comfortably. 

However, creating cold air is far more challenging. Particularly when you consider the considerable heat generated from the engine compartment. However, technological developments have made an ingenious method of utilizing a chemical agent applied with the appropriate conditions to create the desired effect. 

How Does a Car AC Work

AC systems are a relatively new addition to vehicles. They were not a standard feature in cars in the US until around the 1960s and 1970s. However, they were still a luxury edition of European cars until the millennium. 

AC systems might be common, but they are still reasonably complex devices dependent on a fragile balance between a few crucial components. There are five key parts.


The purpose of the compressor is effectively to turn low-pressure gas or refrigerant and pushes it through a tiny space to drastically increase its pressure. This is a reasonably simple but critical component essential for the chemical process, which is required in the 5 stage process.

Typically it is powered by a spinning ribber serpentine belt attached to the drive crank of the engine block.


This component helps convert the refrigerant gas into a stable liquid. It is designed to process the state change, which naturally releases heat as part of the chemical process.

Often it is mounted near the front of the vehicle to allow the heat to escape more quickly through the cooling radiator. 


The dryer is designed to be an ongoing maintainer of the condition of the refrigerant. It is designed to remove contaminants from the delicate system to ensure an efficient ongoing process. 

Essentially, the system is designed to continually cause a chemical reaction in a pressurized condition. Therefore, any foreign material in the system will quickly compromise the processes and potentially damage the intricate process. 

The dryer removes any excess water and filters out any unnecessary material. Due to the nature of driving, hazardous fluids like engine oil and grit from the road can penetrate the AC unit, compromising its capacity to work correctly. 

Metering Device

Metering devices regulate the internal refrigerant pressure to dissipate heat from the fluid as it changes pressure quickly. Critically, this valve system will maintain the refrigerant in its liquid form to regulate rather than heavily manipulate temperature. 


The evaporator is designed to alter the state of refrigerant back to a gas. It rapidly cools the unit’s temperature, allowing the surrounding air to cool down. The cooled air is blown into the cabin, rapidly reducing the temperature. This is the only component mounted near the cabin to allow the coolest air to be passed through and enjoyed by the occupants. 

Symptoms of Low Refrigerant

As part of the lifecycle of a car’s AC unit, its refrigerant level must be topped up periodically. So naturally, the refrigerant will escape from the AC unit over time.

Many systems are designed to utilize the chemical compound to lubricate the rubber seals to ensure they remain functioning. 

However, many will need to be made aware of the typical symptoms that indicate the AC refrigerant is low and requires a refill. There are four key indicators to notice early, which means the AC unit requires some attention. 

Air Temperature

Firstly the most obvious symptom of low refrigerant is that cool air fails to reach the low temperatures. When the AC is on, the car owner will notice that the temperature is not as low as it once did. It indicates that the AC system fails to function optimally. 

Visible Leakage

During the regular inspections of the engine bay, the AC tubing and component should be thoroughly inspected for leakage. Often it will appear as if a milky residue is visible at the contact point between all components. 

Try wiping away the residue and wait to see if the leak reappears quickly. This will be a clear sign of an ongoing leak which should be rectified before the system is recharged. 

AC Clutch Failure

A refrigerant monitoring system is automatically assessed every time the car is turned on. As the system engages a clutch mechanism to measure the levels, it should be a seamless process that goes effectively unnoticed. However, if the refrigerant is low, there will be an evident audible clicking noise. This clearly indicates that the levels are too low and need attention. 

How to Recharge an AC

There are several simple stages to ensure the refilling process is fully completed. Although these steps are reasonably simple, following them accurately and in the correct order is crucial. 

Step 1

The car engine must be turned totally off before the process begins. If the car has been driven, allowing the vehicle to cool for around 30 minutes is a good idea. 

At this point, the hood of the car should be lifted to expose the engine bay to allow for easy access to perform maintenance. Next, identify the location of the AC inlet valve, usually located in the right-hand section of the bay.

If you are struggling to find the valve, refer to the car manual, which will accurately illustrate where to find it. Typically, it will have a protective cap to prevent it from taking in foreign material. 

Step 2

Assess the user manual further to confirm the correct chemical base that should be used to refill the AC. There is a variety available.

However, the manual should accurately point you in the right direction. Next, purchase the correct refilling kit in keeping with these standards.

The refill kits often come in an integrated pressurized can designed to make the process as easy as possible. 

Step 3

Refilling the AC unit at home will typically be completed using a handheld gas container with a primitive pressure gauge. Attach the gauge to confirm that there is too little pressure in the system.

Often there is a low-pressure indicator on the can, which will confirm that refilling is required. 

Step 4

Activate the can to allow the refrigerant to flow into the system. Continually monitors the pressure gauge to assess how full the system is.

There should be a maximum pressure indicator on the can, which must not be exceeded. It could potentially damage the system should it be exposed to too much pressure. 

Step 5

Once the system is at pressure, it is essential to release the refilling can smoothly to prevent excess air from escaping. Ensure that there is no sound of air escaping from the system, which may indicate damage to the pressurized tubing. 

Next, restart the vehicle and confirm that the AC works as expected. If there is a problem, it should ideally be taken to a garage to diagnose and resolve a potential issue in this complicated system. 

This article has been constructed to inform the average car owner precisely the significance of AC units within their beloved vehicles. After reading this article, you will be equipped with the knowledge of how to maintain these sophisticated cooling systems accurately.

Maintaining them properly will ensure they function optimally when needed and do not wear out prematurely. So if it is your first attempt, do not be scared. Please review all of the information above thoroughly and go for it.