How does an aircon work?

Singapore and air conditioners have an unbreakable bond. Perpetually hot weather with high humidity is a way of life in Singapore. Air conditioners make the surroundings cold, moisture-free, and tolerable.

With the flick of a button, your room can be cooled within minutes. Let’s understand how this magical appliance works.

Before we understand the working of the aircon, here’s a list of the core components of the unit.

  • Compressor
  • Condenser coil
  • Evaporator coil
  • Refrigerant
  • Piping
  • Thermostat
  • Fan
  • Other control devices

Working of an air conditioner

The AC uses a “refrigeration cycle” to remove heat from your room and pump it out to the atmosphere. The aircon is quite similar to a refrigerator in terms of working.

The compressor, condenser coil, piping, and evaporator coil form a closed loop. A pressurized chemical called refrigerant is pumped into the system at the time of installation.

Here are the steps how your aircon works:

1. The refrigerant is compressed by the compressor (outdoor unit). Compression of gas produces heat, so the refrigerant gas gets heated above atmospheric temperature.

2. This gas is then pumped through the condenser coil. The coil has a large surface area and a fan to blow air over the coil.

3. The pressurized refrigerant loses its heat to the atmosphere when it passes through the condenser coil.

4. The pressurized gas then travels to the evaporator (indoor unit).

5. The evaporator allows the gas to expand (lose pressure). Expansion causes gas to absorb heat.

6. The evaporator coil gets chilled as the heat is absorbed by the gas inside the evaporator coil.

7. A fan blows air through the chilled evaporator coil, and the air inside the room loses heat.

8. The heated refrigerant is then pumped to reach the compressor.

This is the refrigeration cycle, and that’s how your AC pumps heat out of your room. All this happens in a closed loop where the gas is present at high pressure even before compression. If there is a leak and the gas escapes, your aircon will not function properly.


How the aircon maintains the temperature?

The AC stops cooling when the room temperature reaches the temperature you set using the remote. There are a temperature sensor and a thermostat that govern how long the compressor runs. The aircon can cool continuously if there is no mechanism to turn the compressor off.

The temperature sensor continuously monitors the air temperature inside the room. When the air reaches the set temperature, the thermostat cuts supply to the compressor, and it turns off. The fan on the indoor unit still blows air to maintain circulation.

When the compressor is off, only the indoor unit’s fan is active along with circuits to control the aircon. When the indoor air temperature rises by a specific value, the sensor signals the thermostat to start the compressor again. The refrigeration cycle starts once again, and the room starts to cool again.


What is an inverter AC?

Inverter air conditioners are the newer generation and have been made available in the last decade. These units promise better energy efficiency and effective temperature maintenance inside your room or house.

The “inverter” is an electrical circuit that can change the speed of the air conditioner’s compressor. Compressor speed directly affects how much cooling the aircon can provide.

Aircon Servicing

What’s the difference between an inverter AC and a traditional AC? 

 A non-inverter aircon switches the compressor on or off when the temperature inside the room moves outside the set range. It means that the compressor isn’t ON for the entire duration of aircon use.

An inverter aircon controls the speed of the compressor to maintain the set temperature. Let’s say you’ve just entered your house, and you want the room to be cooled fast. You could set your aircon to a “Turbo” mode if equipped. The compressor runs at maximum speed and cools the room quickly.

Consider now that you’ve set a temperature of 23 degrees. The inverter will slow down the compressor and use a speed just enough to maintain 23 degrees inside your room. The compressor runs for the entire duration of aircon use.



Turning the compressor ON and OFF hundreds of times every day causes greater wear and tear of the mechanical parts. When a compressor starts, it pulls a large amount of current, which also loads the electrical circuit.

Inverter aircon compressors do not require this ON-OFF-ON cycle; hence, they have better longevity and energy efficiency.

Regular aircons thus require frequent maintenance and repair. MCL Air Conditioning is one of the best providers of aircon servicing in Singapore. MCL is reliable aircon company in Singapore which undertakes installation, servicing, and repair jobs. The technicians are well-trained professionals. You can expect the best quality service when you call MCL Air conditioning.