A car AC compressor is an essential element that you cannot think of going out on a hot summer day without it in your car. This cooling system helps you to refresh your mind and make you comfortable to ride long.
Many people think that the compressor creates cold air, which is not valid. It only removes hot air from your car.
Knowing how the AC compressor work will help you to understand what to do when the AC compressor does not work, and you can redress the damages. It is the most prominent part of the car because when it goes off, you will start sweating.
Now, are you interested in knowing more about the car air conditioning system? Keep following the article.
Air Conditioning System Components
If you will familiar with all the components of the air conditioning system, you will understand the vehicle cooling system more frequently. Also, you will get many answers you need to know.
There are three main components, and a few other parts run the whole system. The three main components are
Air Conditioning Compressor
The car ac compressor is the central part to air condition your car like other refrigerators does in your home. You can call it the heart of the air conditioning system. The job of the compressor is it compresses the refrigerant then it turns out into liquid.
Then the compressor moves the refrigerant into a pipe. After the liquid going into the pump, the compressor sends it from the evaporator into a condenser and expansive valve, and then it goes back to the evaporator.
There are three types of air conditioning compressor:
- 2 cylinder reciprocating Piston type
- four-cylinder radial type
- 6 cylinder Excel type
When the compressor sends the liquids, the liquids turn into gases because the compressor only compresses gasses, then raises its temperature into the condenser.
The compressor connects to the engine with a belt. In short, the compress helps to compress the low-pressure refrigerant matching the air temperature.
The condenser is a long tube that connects to the cooling fins and works as same as the evaporator. It also works like a radiator and can take advantage of the air. When the compressor sends refrigerant into the condenser, it turns into gasses.
The process creates very high heat, but the twisting tube of condenser flows the refrigerant back and forth and makes it fresh. So the gasses turn into liquid again.
After those processes, the high-pressure liquid(pressure gas) in the expansion valve will go back to the evaporator. The condenser is the most natural part of the AC system, which you can check anytime you want. It is located in front of the radiator.
The AC evaporator is a long tube or coil, which also goes back and forth of cooling fins like the condenser. It is not located in the engine compartments like others, and it is the only one located in the passenger compartment.
When the refrigerant enters the evaporator and turns out into the liquid, the fan starts to blows warm air over it.
The temperature might be at least 32 degrees Fahrenheit which helps the liquid refrigerant to boil. It will turn out a gaseous state again, so the refrigerant absorbs the heat from the warm air. After absorbing heat from the air, the air start was cooling.
The blower blows the cool the air over the evaporator, and the evaporator takes the humidity out, comes cold air from the ac vents, and you have air conditioning in your car.
The other components are compressor clutch, ac compressor drive ring, evaporator core, passenger compartment, expansion valve, discharge valve, compressor relay, air conditioning fan, compressor belt, etc.
How Does the Compressor Work
To know about the ac compressor and how it works to cool the interior of your car, go to the engine compartment, and you will see where the ac compressor sits. It sits on the crank side of the vehicle.
You will see a low- and high-pressure hose, a drive belt, and a couple of bolts, which is at least 12 millimeters. If you have a better idea about each component, you will understand how the compressor work.
Ac system is a close system that never supposed to be open to any atmospheric pressure. Sometimes, a problem occurs in the ac system, and we have to repair it.
Because of that, the AC system loses its refrigerant. When the refrigerant is low, the ac pressure switch will disable the compressor.
Car AC Working Diagram
Understanding how AC works needs someone better understanding of the whole process. You can see AC diagrams to understand the AC system and how the compressor works to cooling the car environment.
Working Process of Car AC Compressor
Ac system works by manipulating refrigerant, and all the order and the refrigerant maintain a cycle between a liquid and gas because the refrigerant goes from liquid to gas. The temperature changes in those different states.
Step 1: Compressing the Refrigerant into Gases
When you turn on the ac, the ac compressor clutch engages the compressor shaft that runs through the ac compressor, and then it starts becoming the shaft inside the compressor and compressing the refrigerant.
The process works in balancing the AC cycle following the compressor. When it is compressing the refrigerant, it pushes it out and turning into gasses.
Step 2: Cooling Down the Refrigerant Gases into Liquid State
After turning into gasses, it goes to the condenser, which is looking like a radiant. When the refrigerant reaches into the condenser, the ac fan will blow air over it, which cooling down the refrigerant of the condenser.
In short, the refrigerant turns into a high-pressure liquid state, and when it leaves the condenser, it still stays in wet condition.
Step 3: Removing Moisture from the System
There is a receiver drier where the high-pressure liquid travels in it from the condenser. The drier removes contaminants and moisture from the ac system.
There are a few reasons for this process. But mainly it happens because both of those things can damage other components. The receiver-drier is a compassionate thing and can rust quickly.
Step 4: Passing from the High-Pressure to Low-Pressure Side
After filling the refrigerant into the receiver drier, it also leaves the drier and travel to the expansion valve or orifice. The orifice is looking like a tube, and the expansion valve is like a small drier.
From where the refrigerant goes, it depends on what car model you have. The orifice and expansion valve works the same and allows the high-pressure liquid and refrigerant to pass a minimal side and the low-pressure side. Sometimes they work a bit differently.
The expansion valve is attached to the evaporator, and it defines the temperature of the evaporator, and the lid allows the refrigerant to pass to the evaporator.
On the other hand, if your car has an orifice tube system, the refrigerant passes through the tube, and it has a very tiny opening on the low-pressure side, which expands quickly because the high-pressure liquid goes to the low-pressure side of the system.
Step 5: Evaporation Process of High-Pressure Liquid to Cool Air
After expanding, the liquid refrigerant turns into gasses again. In this process, it’s going to use a lot of heat. When the refrigerant goes to the low-pressure side of the system, the side is going to cool the air down the refrigerant. And when this happens to the refrigerant, it goes to the evaporator.
The evaporator core is the coldest part of the ac system. It has a blower fan that blows air over the evaporator. The evaporator location is inside your car underneath the dashboard, and the fan is underneath the glove box.
Step 6: How Cooli Air Passes Through the Vents to Passenger Compartment
The evaporator absorbs the heat of the air that’s flowing over the evaporator. After that, it cools down the air, and the air travel through the dash and comes out from the vents.
After the refrigerant leaves the evaporator core, it returns to the ac compressor, and the whole thing is just going to keep repeating as long as you turned on your ac.
Symptoms of a Bad AC Compressor
There are a lot of things to know about the car. Before repairing a bad ac compressor, you need to know the symptoms accurately so that it won’t make any delay. Some symptoms are
Releasing Hot Air
The main job of an ac compressor is to release cold air to your car. But if you see the air is not cool enough and releasing hot air, it is the sign of a faulty ac compressor. It may have leaks or lack of gas or any other reason.
A smoothly running ac will make no noises; also, the fan will work properly. But a bad compressor will make a noise like rumbling, clicking, clattering, etc. the ac will even start vibrating. The problem may happen because of electrical chaos.
Won’t Turn it On
The cooling fan is an essential part of the ac, and if you see the fan is not working, the compressor will not release col air.
The ac system has many tubes in it. If there is any leakage, the ac will not work correctly. Leakage can be cured easily, so do not leave it for repair.
Compressor Clutch not Moving
The compressor clutch plays a vital role in the ac system. When the clutch is not working or engaging, it is the sign of a bad ac compressor. So you need to replace the clutch or repair it. Sometimes, you need to replace the whole compressor.
How to Test the AC Compressor
Even the best car ac compressor needs regular testing for better service. You should test once a month in every component of your ac system. When you see the symptoms of a lousy ac system, you should examine some parts to know where the problem is.
Turn on the AC
The first thing you have to do is to turn on the ac to know where the problem might behave. Check the fan system, or the air if they work correctly.
Test the Compressor
If there is not any visual problem, check the compressor if there is any damages or leakage. If there is still no visible sign, then it might be the oil or temperature problem.
Inspect the Belt
You should inspect the car engine and the compression before inspecting the compressor part to be sure if any other part has some issues or not.
After inspecting the compressor, check the belts and pulley if they are in good condition. If the straps have crack or leaks, the ac will not be working correctly.
Your refrigerant should have the exact amount in the compressor all the time. Lack of refrigerant or any leakage in it will damage the compressor. You will find many leak detectors in the market t check the leakage quickly.
Check the Start Button
Ac system gets its power from the engine. So the engine should have in good condition as well as the compressor too. To check this, set the ac max and wait for a while.
Also, the switch should be strong enough because it controls the high and low-pressure sides.