Simple basic about Automotive A/C - Part 4

Well here comes part 4 of the basic a/c understanding. Here i gonna talk about Expansion valve, Evaporator, and Ventilating Blower (which can also called as Blower in short).


Currently there is 2 kind of Expansion valve that can be found in car a/c, both work in same principle.

Before refrigerant go into the evaporator, it will travel through filter drier, then arrive at expansion valve. In this stage, the refrigerant is in its liquid state, and it will feel warm to touch and is very high in pressure. Here is where the magic happen. The expansion valve will convert this high pressure liquid refrigerant into low pressure refrigerant. The lost in pressure of refrigerant will convert the refrigerant from warm to cold immediately.


Evaporator comes in different pipe arrangement and shape. The left is Serpentine type, while right is Parallel type.

This cold low pressure refrigerant will then enter into Evaporator and it rapidly cool down the evaporator which make the evaporator colder than the surrounding air. The Blower will then blow the hot and humid surrounding air through the evaporator where the hot air will be convert into cold dry air and leave the evaporator. This cold air is what we feel at the ventilating in our car.


Picture at left is how the Evaporator work, and right is what Blower looks like.

The low pressure cold liquid refrigerant will be convert into its gases state while travel inside the evaporator. This low pressure gases refrigerant will be suck back into compressor and the whole process begin again in continuous loop.

So this is all the basic we need to know about automotive air condition. I may have rush to explain this in simple, because many parts cannot be explain in this 4 parts of posts. I will post each of the parts related in their dedicated post. In there i will further explain in detail.

Stay tune for more understanding of our car a/c system.

Simple basic about Automotive A/C - Part 3

Welcome back to this part 3 of basic a/c. On last 2 post, i have talk about compressor, clutch, condenser, and condenser fan. So in this post, i will talk Pressure Switch, Service Port, and Filter drier.


This is A/C Pressure Switch used in car a/c. This switch comes in different design and shape, but all with same principle.

So, the pressure switch is use in a/c to take reading of refrigerant pressure inside the a/c system. It is use to regulate of how much pressure the system can take, and if the pressure is below or higher than the system can take, then the system will shut off the compressor to prevent major parts failure. This switch usually is placed at High Side of the a/c system, depends on system design, some car will come with two switch, one in Low Side, and one in High side.


This are the several kind of Filter Drier that can be found in cars. Deepening on system design, the filter will have different shape.

Filter Drier is use in a/c as an humid absorbent. This filter contain desiccant that can absorb small amount of water/vapor that may get into the a/c system during installation and service. A/C system required a dry condition for it to function properly. If there is too much water/vapor inside the system, the refrigerant will freeze up and thus blocking of refrigerant flow will happen.


Some of the service port that can be found in car a/c. 

Service Port is use by a/c technician to plug a pressure meter to take reading of the internal refrigerant pressure. This port is very vital because it provide access to top up, recharge and also to recover the refrigerant in any a/c service.

This three parts will have its dedicated post in future. Now i will just focus on basic understanding of the car a/c.Stay tune for my last part.

Simple basic about Automotive A/C - Part 2

This is part 2 of the basic for automotive air condition. In last post, i have talk bout Compressor and Compressor Clutch. So in this post, i will explain the use of Condenser and Condenser Fan.

After the compressor pump the refrigerant out from the compressor, the refrigerant will be very hot and is in gases state. This hot gases will then be pushed to condenser to cool down its heat so that it can be used to generate cold air.


On the left is Condenser and the right is Condenser fan (can also called as Cooling Fan)

Condenser as the name suggest, is use to cool the hot refrigerant through the mean of heat transfer. The hot gases refrigerant contain so much heat when it leave compressor, it will be gradually cool when it travel in the condenser fin.

The heat will be transfer to the surrounding air around the condenser using a condenser fan (can also called cooling fan). The fan will push the surrounding air so that the air travel through the condenser and carry the heat away from the condenser when the air leave the condenser. This will cool down the condenser and in the same time cool down the refrigerant inside the condenser.


Picture show how the heat leave the condenser

The hot gases refrigerant will be cool down and become warm liquid refrigerant when it leave the condenser. This liquid refrigerant will be use to produce cold air when it reach Evaporator.

Stay tune for my next part.

Simple basic about Automotive A/C - Part 1

This is my first posts for my dedicated blog made just for automotive air conditioner. I mean to share my knowledge, how to diagnose and solves all problem related to air condition in our cars. In Malaysia, all of us that have owned a car is basically not know so much about our cars' a/c system, how to go around problem and how to solve the problem. So i will share my knowing on car a/c so that we can learn how to troubleshoot when problem arise in our cars' a/c system.

So in this blog, i will share a basic about our automotive a/c, which i will make it simple to understand. All of the picture i use in here is taken from Google Picture, so i do not hold copyright to all those pictures, neither do i do any alternation to the picture (unless state otherwise) and all can freely use as it is.



This is a simple diagram showing components which got in our car a/c. And the first i want to explain is Compressor. Compressor is a "heart" of the a/c in all kind of air conditioner found around this globe. If the "heart" fail, the a/c system will stop function, and end of story. But my story will not end here XD.

The function of the compressor is to circulate refrigerant from condenser to evaporator. Its work just like our body heart which pump our blood throughout our body, in air condition, this "heart" is pumping refrigerant throughout the a/c system.


This is a sample of compressor, the left side have a pulley "Multi Groove (can also called PK Groove)" and the right side pulley is "Wedge Groove (can also called V-Belt Groove)". 

For the compressor to work, it required a moving parts to move the rotary shaft using what is know as compressor clutch. This clutch is attach to rotary shaft of the compressor.

Picture shown is Magnet Clutch Set, which consists of Pulley in the middle, a Clutch at bottom left, and a Magnet Coil of bottom right.

The pulley is attach to the body of the compressor, while the magnet coil is located behind the pulley, also attach to the body of the compressor, and the clutch is in front of the pulley. All three of this parts do not make contact to each other. The pulley will move along with car's main pulley driven by either using a V-Belt or a Multi-Groove belt. The magnet coil and the clutch will not move along with the pulley. The magnet coil will need to be magnetize first just then it will "Pull" the clutch to the pulley. When this happen, the clutch will stick to the pulley and it will move along with the pulley. While this happen, the clutch will drive rotary shaft of the compressor and thus make the compressor work.

This is Part 1 of this basic a/c explanation, stay tune for Part 2.