AIR CONTIONERS
Pre-syndication on how air conditioners work:In the absolute basics, air conditioners used for cooling, work under five basic building blocks. How? Through refrigerant:
Compression
Condensation
Expansion
Evaporation and boiling. Boiling? And it is suppose to cool air?
Heat transfer or heat exchange
These five processes, work together to:
Change the air property for you, by
Lowering the temperature.
An air conditioner system in its simplest form consists of:
A compressor
A condenser coil
A receiver and dryer
An expansion valve
An evaporator coil
Fans
Tubing to make the system, a closed loop system
Refrigerant
Yes, air conditioners work in a closed loop arrangement and filled with necessary quantity of refrigerant to cool the air. That is the secret (well, not anymore) of how air conditioners work out the cooling effect.
Fundamentally, ACUs (air conditioning units) have two sides. The high pressure side and the low pressure side.
The high pressure side consists of the discharge of the compressor, the condenser, and the inlet of the expansion valve.
The low pressure side consists of the outlet of the expansion valve, the evaporator, and the suction of the compressor.
High pressure side. Refrigerant gas' temperature rises up due to compression from the compressor
Outdoor air is passed through a heat exchanger named, condenser. Condensation of refrigerant happens here.
Refrigerant will be cooled down - to liquid state, and air will be heated up.
Motion of air is forced by condenser fan
Warm liquid refrigerant
Expansion valve or device. The device that allows pressure build up from the compressor
Next, on how air conditioners work, the low pressure side. Expanded liquid refrigerant. Liquid refrigerant will "see" low pressure area after expansion valve, thus it will start to form refrigerant mist
Refrigerant evaporation and boiling will happen at the evaporator, as temperature within the room (7), is higher than the refrigerant's boiling temperature.
Room's warm air, will be passed through the evaporator, and cooled down. Forced draft is helped by the blower
Boundary of the room
Superheated refrigerant vapour at about 10 oC (50 oF). Useful for compressor's cooling
Last, and by no means the least - the compressor itself. Cycle starts back from (1).
That was the pre-syndication part of how air conditioners work. Now, getting down to real business of its operations.
We’ll start with the high pressure side:The compression cycle
Let us start at the compressor, the hard worker in how air conditioners work topic. This air conditioner part is used to compress the refrigerant gas from evaporator coil’s outlet.
I will use the simplest form of compressor to illustrate its working principle; the reciprocating compressor, also known as piston compressor.
As the driver, which is usually an electric motor, rotates; the piston is set to move on a continuous linear motion between two positions, within the casing.
There are two spring operated valves located at the end of the gas chamber. One is a suction valve, and another is a discharge valve. The suction valve is arranged such that, it will only open towards the chamber, and discharge valve away from the chamber.
Let us take a starting point when the piston is closest to the valves. At this point, let us also assume that both valves are in closed position.
As the piston moves away from the valves quickly, a space of low pressure is created within the chamber. Due to the negative pressure difference between the chamber and outside it, the suction valve will open, allowing refrigerant gas from suction side to rush into the enclosed space.
This happens as the force from the pressure difference overcomes the spring force.
Due to the construction of the compressor’s shaft, the piston will be on a momentary stop at the end of the suction cycle. During this moment, pressure difference between suction line and gas chamber is very little, allowing the spring force to pull the suction valve towards closed position.
Now what happens? The piston starts to move towards the valves again.
Compression will happen, because both valves are closed; and the piston is quickly reducing the volume of the gas.
Déjâ vu! I know you would say that. Compression takes place, and positive pressure difference between the gas chamber and outside it, will force open the discharge valve.
As a result, air conditioner's refrigerant gas will be forced out through the discharge line.
Quite slow process isn’t? Not quite. It’s very (and very is an understatement) quick. I can’t explain as fast as a 1000 over rpm reciprocating compressor. That is 17 suctions and 17 discharges in one second.
Compression
Condensation
Expansion
Evaporation and boiling. Boiling? And it is suppose to cool air?
Heat transfer or heat exchange
These five processes, work together to:
Change the air property for you, by
Lowering the temperature.
An air conditioner system in its simplest form consists of:
A compressor
A condenser coil
A receiver and dryer
An expansion valve
An evaporator coil
Fans
Tubing to make the system, a closed loop system
Refrigerant
Yes, air conditioners work in a closed loop arrangement and filled with necessary quantity of refrigerant to cool the air. That is the secret (well, not anymore) of how air conditioners work out the cooling effect.
Fundamentally, ACUs (air conditioning units) have two sides. The high pressure side and the low pressure side.
The high pressure side consists of the discharge of the compressor, the condenser, and the inlet of the expansion valve.
The low pressure side consists of the outlet of the expansion valve, the evaporator, and the suction of the compressor.
High pressure side. Refrigerant gas' temperature rises up due to compression from the compressor
Outdoor air is passed through a heat exchanger named, condenser. Condensation of refrigerant happens here.
Refrigerant will be cooled down - to liquid state, and air will be heated up.
Motion of air is forced by condenser fan
Warm liquid refrigerant
Expansion valve or device. The device that allows pressure build up from the compressor
Next, on how air conditioners work, the low pressure side. Expanded liquid refrigerant. Liquid refrigerant will "see" low pressure area after expansion valve, thus it will start to form refrigerant mist
Refrigerant evaporation and boiling will happen at the evaporator, as temperature within the room (7), is higher than the refrigerant's boiling temperature.
Room's warm air, will be passed through the evaporator, and cooled down. Forced draft is helped by the blower
Boundary of the room
Superheated refrigerant vapour at about 10 oC (50 oF). Useful for compressor's cooling
Last, and by no means the least - the compressor itself. Cycle starts back from (1).
That was the pre-syndication part of how air conditioners work. Now, getting down to real business of its operations.
We’ll start with the high pressure side:The compression cycle
Let us start at the compressor, the hard worker in how air conditioners work topic. This air conditioner part is used to compress the refrigerant gas from evaporator coil’s outlet.
I will use the simplest form of compressor to illustrate its working principle; the reciprocating compressor, also known as piston compressor.
As the driver, which is usually an electric motor, rotates; the piston is set to move on a continuous linear motion between two positions, within the casing.
There are two spring operated valves located at the end of the gas chamber. One is a suction valve, and another is a discharge valve. The suction valve is arranged such that, it will only open towards the chamber, and discharge valve away from the chamber.
Let us take a starting point when the piston is closest to the valves. At this point, let us also assume that both valves are in closed position.
As the piston moves away from the valves quickly, a space of low pressure is created within the chamber. Due to the negative pressure difference between the chamber and outside it, the suction valve will open, allowing refrigerant gas from suction side to rush into the enclosed space.
This happens as the force from the pressure difference overcomes the spring force.
Due to the construction of the compressor’s shaft, the piston will be on a momentary stop at the end of the suction cycle. During this moment, pressure difference between suction line and gas chamber is very little, allowing the spring force to pull the suction valve towards closed position.
Now what happens? The piston starts to move towards the valves again.
Compression will happen, because both valves are closed; and the piston is quickly reducing the volume of the gas.
Déjâ vu! I know you would say that. Compression takes place, and positive pressure difference between the gas chamber and outside it, will force open the discharge valve.
As a result, air conditioner's refrigerant gas will be forced out through the discharge line.
Quite slow process isn’t? Not quite. It’s very (and very is an understatement) quick. I can’t explain as fast as a 1000 over rpm reciprocating compressor. That is 17 suctions and 17 discharges in one second.
You might ask a question. “Ok fine, it draws in gas from suction line and discharges it to a discharge line. But if the discharge is to an open space, I won’t have any pressure build up!” You’re right.
That is where a form of restriction is required to allow pressure build up, but that is jumping the gun for the moment. Let’s move towards the next part in sequence. Believe me, how the sequence is arranged makes air conditioners work in correct manner.
