How Air Conditioner Works?

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How does an air conditioner work? Well, many of us have this question in our minds.

There is no rocket science behind how an AC works. The functioning is very simple; it removes the heat inside your home by transferring it to the outside environment. You didn’t expect it to be that easy! Did you?

There are many other components that comes into play during this process. They are a Compressor, Condenser, Expansion Valve, and an Evaporator Coil.

To make the understanding easier for you, let us discuss in detail each segment below. Read on to know more:

Components of Air Conditioner

As mentioned earlier, an air conditioner has crucial components that aid in the functioning of the unit. You can find different types of air conditioners but the working principle and components are mostly identical. With this knowledge, you will be easily able to identify the problem with your air conditioner unit in the future and try to resolve it as early as possible.

Let us learn what each module does and how it contributes to the purpose.

1. Refrigerant

A Refrigerant is the most vital part of the air conditioner. As we all know, it is a cooling agent or a fluid responsible for the refrigeration cycle in the cooling system.

Now that we know what the role of a refrigerant is, let us now try to understand how it functions. The coolant changes from one state to another, i.e., from liquid to vapour, at flexible temperatures in the refrigerant cycle. During this process, it takes in the heat and then sends it outside.

There are different types of refrigerant gasses used in air conditioners, and they are – HFC, HCFC, and HC. The most common HFC (hydrofluorocarbons) used is R-410A. In HCFC (hydrochlorofluorocarbons), it is R-22, also known as Freon. In HC (hydrocarbons) R-290 and R-600A are the most widely used refrigerants.

2. Evaporator Coil

An evaporator coil is yet another significant component of the air conditioner, located in the indoor unit of the system. The primary job of an evaporator coil is to extract the indoor heat and humidity from the air, and add it to the refrigerant. These coils are usually copper, aluminum, steel, or similar highly conductive materials for easy heat transfer.

3. Compressor

A compressor is the heart of an air conditioner, located in the outdoor unit of the system. It is responsible for circulating the refrigerant between the evaporator and condenser coils.

The compressor works by heating the refrigerant. It helps the gas to reach a temperature that is higher than the outside. In simple words, it converts the low-pressure gas into a high-pressure gas, which is high temperature. To dispense the heat outdoors, the refrigerant must be hotter than the outside temperature.

4. Condenser

The condenser is another essential component of the air conditioner, located in the outdoor unit of the device. It is a counterpart to the compressor and plays a vital role in the functioning of AC. The only task of a condenser is to remove the heat from the high-pressure and high-temperature refrigerant. In other words, it absorbs the heat from the coolant and converts it

into a liquid state.

5. Expansion Valve

An expansion valve is a device specially designed to regulate the refrigerant flow in a refrigeration cycle. You can locate it between the compressor and the condenser coils.

6. Fan & Blower

A fan or blower of the air conditioner has its share in the functioning of the unit. While the outdoor component fan disperses hot outside through the condensing coil, the indoor fan or the AC blower fan discharges cool air into your home.

7. Thermostat

A thermostat is the temperature regulator of an air conditioner. This is how it works. The thermostat reads the indoor temperature and then directs the AC unit to turn on and off accordingly. You can adjust the temperature settings in a thermostat based on your needs.

The higher you set the thermostat, the lower your electricity bills will be.

How Air Conditioner Works?

Now that you are aware of the various components in the air conditioner unit, let us now try to understand how it functions.

To begin with, the entire air conditioning process starts with the refrigerant, also known as the coolant. It absorbs the indoor heat and transfers it outside when circulating through the coils. The coils guide the cooling agent from inside your home to the outdoors and back inside again.

Take a closer look at the below picture to understand the process better:

Let us say you switched on your AC and set the temperature to around 18 degrees Celsius. Now the thermostat installed in the unit senses the variation in the room temperature and the set temperature.

The device immediately draws this hot air inside and allows it to flow over the evaporator coils.

The coolant is now in its liquid state. When passing through the evaporator coils, it absorbs this heat to become a low-pressure gas. This is how it removes the heat from the inside air passing over the evaporator coils.

Besides absorbing the heat, the evaporator coils dehumidify the room by getting rid of the moisture.

This refrigerant, in its gas state, now passes through the compressor. The compressor does its job of compressing the gas and increases its temperature, making it a high-pressure gas.

This high-pressure gas now passes through the condenser, which condenses it into a liquid.

The refrigerant that reached the condenser as hot gas quickly became a cool liquid. During the condensation process, the heat dissipates through the condenser metal fins. To simply put, when the refrigerant vacates the condenser, it is no longer hot but becomes a high-pressure liquid.

This high-pressure fluid now flows through the expansion valve and gets converted into a low-pressure liquid. In addition to cooling the fluid, the valve also regulates the liquid refrigerant flow into the evaporator. This makes the refrigerant get back to its initial state to start the cycle all over again.

The entire process is a cycle that repeats over and over for continuous refrigeration until the AC unit attains the set temperature. In short, the AC unit takes the warm air inside and disperses it back into the room continuously until the air in the room becomes cool.


To sum up, the process of air conditioning is less about increasing the cold air inside the room and more about removing the existing heat.

I hope this article gave you a clear picture of how an AC works.

If you find this article useful, write to us in the comments section below. If you have any questions or require more information, you can let us know in the comments. Stay cool, stay safe.

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