How Does A Centralized Air Conditioner Work? Explained

Most parts of India see a peak in temperatures, especially during summer season and that’s why we have air conditioners installed in homes. Of all the types of ACs; a central air conditioner is among the most efficient and cost-effective when it comes to cooling an entire house or an entire building. But how does this centralized air conditioning work? Let’s find out.

Also Read: AC Buying Guide

What is a Centralized Air Conditioner?

A centralized or a central AC is made up of numerous components from an evaporator coil, condenser coil, compressor, furnace, air handler, blower fan, and so on. It acts as a single system that supplies cold air to a larger area such as an entire floor; or an entire building using its set of air ducts spread across a structure. Unlike a window or a split AC, a centralized AC doesn’t require setup in every room; instead, the air ducts laid out in every room in a building are enough to deliver cold air to all the rooms.

The schematics of a centralized air conditioner will astound you; but that’s why we are here to get the entire process of how a Centralized Air Conditioner Work. Let’s have a look at the process with steps from a microscopic level.

How does a Centralized Air Conditioner Work?

When considering a central AC system, you have two major components i.e. inside the home and outside the home.

Inside the Home: Also referred to as the “cold side” of the system, it is where the warm indoor air is cooled when it goes across the cold cooling coil filled with refrigerant that absorbs the heat from the indoor air and converts itself from liquid to gas. Here, the cold air is not distributed throughout the house.

Outside the Home: Contrary to the first half, the ‘Outside the Home’ is referred to as the ‘hot side of the system. The refrigerant converted from liquid to gas in the former stage is now under compression; and then enters the larger coils in the outdoor unit called the evaporator coil. The refrigerant releases the absorbed heat here and converted it back to liquid (from gas); and goes back into the condenser coils to repeat the process over and over again. Finally, the absorbed heat is then removed from the system releasing it into the air and that’s the process.

A Microscopic Level on How a Centralized Air Conditioner Works

One of the integral components of a centralized air conditioning system is the thermostat. Placed inside the home in a place shielded from direct sunlight; it is where you can command the system to increase or decrease the air temperature. Note that the thermostat automatically disconnects the central AC once it senses an optimum temperature and automatically kicks off once it senses that the room temperature has risen. Now let’s see how the cooling process takes place.

First up, the fan inside the indoor unit starts rotating to suction the hot air and uses the return air ducts to do the same. The air goes through a filter that strips it from dust, dirt, lint, and other airborne particles. The warm air is then relayed towards the cold evaporator coil which contains refrigerant in liquid form. 

The refrigerant absorbs heat and in turn, converts itself from liquid to gas. It is when the indoor air that makes its way through the return air duct into the evaporator coil starts cooling. The cold air is then relayed back to the rooms using air ducts spread across a house or a building.

Now that the refrigerant is in a gas state, it is relayed through a copper coil into the compressor outside the home where it is pressurized. Next, the pressurized gas is then sent through the condenser coil; whereas the fan helps dissipate the heat which is then released outside. The refrigerant is then fed to the expansion device where it is finally converted from hot liquid to cold liquid bringing down its temperature. Finally, the cold liquid refrigerant is sent upstream to the evaporator coil located in the indoor unit and the process repeats hereafter.

Also Read: Explained: Different Types Of Air Conditioners

Types of Centralized Air Conditioners

When talking about electronic appliances, it is quite common that there are multiple options available in the market. The Centralized air Conditioner too comes in two varied types – Split System and Packaged Air Conditioner. Let’s see how different they are in real life. 

Split Central Air Conditioner

As the name suggests, this type of air conditioner is divided into two units – Indoor and Outdoor units. The process of how centralized AC works above explains the same mechanism for a split AC.

Packaged Central Air Conditioner

Similar to a window AC where all the components of the AC are housed in just one single unit, a packaged central AC works with the same concept. It is installed outside the home or on the rooftop of a building; where it uses the web of air ducts and return air ducts to carry out its cooling functions. Some of the systems have heating functionalities too. You can either get an air-cooled or a water-cooled version where the condensers are cooled using surrounding air and a cooling tower filled with water, respectively. 

Also Read: Best Voltas Split Air Conditioners In India