Air Conditioner 101: How Does An Aircon Work?

In our hot and humid country, an aircon is becoming more of a necessity than a luxury.

An air conditioner works by sucking in hot air from the room and then replacing it with cool air. But how does an aircon actually achieve this?

The refrigeration cycle

An aircon works by taking the heat off the air, transferring this heat outside, and then blowing the same air (now devoid of heat) in to the room. It does this through the process of evaporation.

When a liquid evaporates in to the air, it absorbs heat. This is why your skin feels cold after pouring alcohol over it.

Much like a refrigerator, an air conditioner harnesses the power of evaporation by continuously evaporating and condensing a refrigerant gas in a closed system.

The cycle goes like this:

Air Intake Panel

Air Intake Panel + Filter

This part sucks the indoor air in to the AC unit.

It makes the air pass through a filter to keep the evaporator clean and to improve air quality.


Evaporator + Blower

The heat from the air is absorbed by the evaporating refrigerant. This turns the refrigerant into a hot gas.

As the name suggests, the blower blows the now cold air back into the room.


The heart of the air conditioner; this pumps the hot refrigerant gas through the condenser to turn it back to liquid,


Condenser + fan

Aside from turning the hot gas back into liquid, this part also transfers the heat to the outdoors with the aid of a fan.

Expansion valve

Expansion Valve

This part greatly reduces the pressure of the liquid refrigerant, bringing its boiling point down. This liquid gets pumped back to the evaporator to start the process again.

Air conditioners act as dehumidifiers

Aside from cooling the air inside our room, did you know that air conditioners also take away humidity from our room?

The dehumidifying effect is a by-product of the refrigeration cycle. When the evaporator absorbs heat from the moist air, it condenses into water droplets. This liquid collects and drains down to the drain pan on the outside part of the aircon.

Types of air conditioners

There are three types air conditioners in the market. They differ in how the parts above are configured. These are:

Window Aircon

Window Type Aircon

This is the most common type of aircon in the Philippines, and it is also the simplest.

This type combines all of the components into one unit. It is mounted on the wall, with the compressor and condenser hanging outside of the wall.

Split Type Aircon

Split Type Aircon

As the name implies, this type of aircon splits the aircon into two units: the indoor component and the outdoor component.

The indoor component comprises of the air intake panel, filter, evaporator, and the blower. This is connected to the outdoor component (comprised of the condenser, fan, and compressor) by a copper tube.

Because of the width of the indoor unit, the airflow will have a wider coverage compared to window air conditioners. making it more efficient in cooling rooms.

Portable Aircon

Portable Air Conditioner

Much like the window type, the portable air conditioner also combines both the indoor and outdoor components into one unit. The difference is that the whole unit is located indoor.

The hot air from the condenser is transferred outside of the house through an exhaust tube that vents out through your window.

Also, the water droplets that form because of the condensation will not have a way to escape outside, which is why portable aircons have a water to tank that you’ll have to empty from time to time.


While most people can go about their lives not knowing how an aircon works, knowing so will provide you with information to make better decisions when buying a new air conditioner. It can also help you improve its performance to get more from it – or at the very least, not break it.

FURTHER READING: Air Conditioner Buying Guide


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