Know How Your Split System Air-Conditioner Works [2024]

Know How Your Split System Air-Conditioner Works

Air conditioners are a great respite from extreme outdoor weather conditions. With emerging technology, there are many types of ACs being launched in the market for every need. But, two dominating models still remain the same – Split AC and Window AC.

If you’re planning on buying an AC, you must be well aware of the difference between both units. Split ACs are being overwhelmingly preferred by consumers due to their ease of usage and cooling capacity. Learn what a split AC is, how a split AC works, and what makes it a good choice for your home.

What is a split AC?

A split system AC has two units – indoor and outdoor. The indoor unit, having the evaporator coil, absorbs the hot air and humidity inside the room. The outdoor unit, having the condenser coil, cools the hot air and pumps it back into the indoor unit. The two units are connected to each other with insulated ducts.

How does a split system AC work

In simple terms, a split AC works by absorbing the heat and humidity from the room and releasing excess heat to the external environment. There are four main components in an AC system – Condenser Coil, Compressor, Evaporator Coil, and Expansion Valve. Let’s see how these different components are involved in the split AC working principle.

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  • The indoor unit absorbs heat and circulates it around the evaporator coil, which has the refrigerant. The refrigerant passes to the compressor.
  • The compressor starts and creates high pressure to heat up the refrigerant. The hot liquid is then passed to the condenser coil in the outdoor unit.
  • The outdoor unit circulates outside air, heats it up, and releases it back into the external environment.
  • The hot refrigerant then passes through the expansion valve, which cools it up. And it is then sent back to the evaporator coil, thus completing a cycle.
  • This cycle is repeated till the desired temperature in the room is maintained. The temperature is set and measured by the Thermostat. After the cooling is done, the compressor shuts down. It switches on again when the temperature rises.

Interesting note: Energy can neither be created nor be destroyed. So, every time the AC removes energy (heat) from the room, it has to release equal energy outside. That’s the basic split AC working principle.

Do split ACs heat and cool?

Split ACs are generally meant to cool the room. But there are new-age all-weather split AC systems in the market that do both heating and cooling. This is achieved by a reverse valve in the AC unit which reverses the flow of heat.

The inside unit simply extracts the cold air from the room and a reverse cycle happens. The air is heated up inside the chambers and released back into the room. These are often known as the HVAC (heating, ventilation, and air conditioning) systems.

Difference between Split AC and Window AC

There are several differences between split AC and portable/window AC systems. We have listed some key points of difference:

  • Window AC generally has all its components in one metallic cabinet, unlike the split AC, which has two units. Since key components like evaporator coil and air filters are placed in indoor units, split ACs also have a longer life span.
  • Split AC is more space-efficient and can be easily installed at any location. Window ACs require more ductwork and need specific locations to be installed. Installation costs of split ACs may be higher than window ACs. But the overall operating cost is much lower.
  • Since the compressor is located in the outdoor unit of split AC, all the noise remains outside. This is not the case with window ACs which can be a lot noisier.
  • Split ACs also have larger compressors, so greater capacity, as compared to window AC units. They can heat up larger spaces faster than window AC systems. Window ACs are only used to heat up small spaces like a room.
  • Window ACs also consume more power than split AC systems, which can be run on inverters too. That’s why split ACs are much more energy-efficient than window ACs.
  • Many companies are now also offering inverter ACs which can handle voltage fluctuations well, unlike window AC units.
  • Due to several advantages, split ACs will cost you a lot more than window ACs. The cost can sometimes be double the average cost of window ACs in the market.

How to choose the right split AC for yourself?

Split ACs come in different sizes (also called ‘tonnage’) based on their cooling capacity. Their compressors differ in tons of air they can cool. To choose the right AC size for you, you must consider three key factors:

Room size

Floor space and the volume of the room determine the size of the AC required to properly heat the room. Higher ceilings need greater cooling capacity. Generally, 100 to 150 sq ft of the area can be easily cooled by a 1-ton AC. A higher cooling capacity is needed for more than 200 sq ft of the room area.


Insulated walls and ceilings require less cooling capacity as they can hold the cold air for longer. But if your room isn’t insulated, you will need higher cooling compressors.

External temperature

If your house is in a location that experiences extreme weather, like Northern India, you will require a higher cooling capacity. Regions will have milder temperatures like coastal areas need lower ton split ACs.


Now that you have a thorough idea of what is split AC and how split AC works, you can make more informed decisions about buying and maintaining your AC. The kind of AC you choose should be dependent on various factors, apart from cost. You should also take good care of your air conditioning systems, with regular checkups and repairs.

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