Today the air conditioners have become very important for us to survive in summers. Especially, for the countries which are near the equator and at topical ranges. The working principle in the air conditioner is similar to the refrigeration in the refrigerators. Today we can see the application of refrigeration in much wider fields other than just making the rooms temperature ambient.
The process of refrigeration has five parts namely
Parts of an air conditioner
It comprises several coils containing refrigerant at a lower temperature than the surroundings. In this system, the cool refrigerant flows through the coil and cools the air surrounding the coil. Then a blower blows the air over it which gives the cool air.
This leads to the change in the state of refrigerant from liquid to gas due to an increase in the temperature.
The most common refrigerants are ) hydrochlorofluorocarbons or HCFCs (like, R-22), hydrofluorocarbons or HFCs (like R-410A) and hydrocarbons (like R-290 and R-600A).
This is the part of the air conditioner where gaseous form refrigerant enters after coming out from the evaporator. Here, the refrigerant undergoes compression to increases its temperature and pressure. Generally, the split ac compressor is located in the external unit and the window ac it is within the body of the air conditioner. The temperature of the refrigerant is much higher than the atmospheric temperature after the compression.
A reciprocating compressor is commonly used in the air conditioner.
Here, the temperature of the refrigerant reduces and its state changes from a gas to liquid. it is also located in the external unit of the AC.
The condenser has multiple coils and a fan that expels the heat from it.
It is also known as throttling device. The purpose of the expansion valve is to control the refrigerant flow. It is present between the condenser and the evaporator. The expansion valve is thermostatic which means it opens and closes with the change in the temperature of the refrigerant in the evaporator with the help of a sensitive bulb.
Working of an air conditioner
The working of an air conditioner always intrigues us. Its process is complex when it comes to understanding it in the thermodynamics terms.
To put it simply, an air conditioner intakes the air from the room and exhales the cool air. Then again it inhales the air from the room ( which is cooler than before) and exhales the cooler air. This cycle continues until the temperature of the room decreases to set temperature.
When we switch on the AC and set it at a particular temperature, the thermostat inside the unit monitors the room temperature. The refrigerant ( at low pressure and temperature) moves from evaporator to the compressor.
Here, the temperature and pressure increases with the compression. Then the refrigerant moves to the condenser which reduces its temperature of and changes its state from gas to liquid.
Further, the refrigerant is transferred to the expansion valve which reduces the pressure and controls the flow of refrigerant. From an expansion valve, the refrigerant is transferred to the evaporator.
This is one cycle and it continues till the desired temperature is set in a room.
What are the types of air conditioners?
There various types of air conditioners available in the market.
Split AC are most common air conditioners in our homes. It is more efficient than window air conditioners. This is due to the fact, it has two different units. One unit has an evaporator and it is inside the room and the second unit comprises a compressor, condenser and expansion valve which is outside the room.
Two different units handle two extreme temperatures. Therefore, it is good to keep them separated.
These air conditioners have a single unit comprising all the parts like compressor, evaporator, and expansion valve. This is the reason why these are less efficient than Split AC.
It is a set up which generally cools big spaces. Here, there are various vents from where the cool air comes out. Under this system, a single unit comprises compressor, condenser, and evaporator. This unit fits on the roofs of the buildings. Moreover, it uses ducts to transfer the cooled air.