How does air conditioning work?

Split system air conditioning is a very versatile climate control solution for everything from a granny flat to a large home but how do they cool or heat our homes so well?

How does split system air conditioning work?

Ambient air is drawn in through the base of the indoor unit gently passing over the cooling pipes (or evaporator) reducing the temperature of the air. The air then flows over a heating element which during the cooler times of year is used to heat the air to warm the room.

The warmed or cooled air is then distributed back into the room via a fan inside the indoor unit.

This process gradually adjusts the air in your room to the desired temperature. A thermostat inside the unit monitors the temperature increasing or decreasing the output to maintain the desired setting.

The cooling pipes in the indoor unit which are used to reduce the temperature of the air have a coolant (or refrigerant) circulating through them. This coolant moves along the pipes in the indoor unit and down to the outdoor unit via a small pipe.

In a liquid state, the refrigerant is very cold which cools the passing air and transfers the heat from the air into the pipes as it is drawn through the indoor unit. When the refrigerant warms it turns from cool liquid into a gas form. The warmed refrigerant gas is fed along the pipes to the outdoor unit where a compressor compacts the gas cooling it down and returning it to a liquid. A powerful fan is used to expel the waste heat from the compressed refrigerant into the outside air.

The cooled refrigerant is pumped back inside to repeat the air conditioning process again.

Common air conditioning myth

A common misconception is that split system air conditioners draw fresh air from outside the building which is then cooled or that the hot air from inside your home is pumped outside. This style of air conditioning only circulates and cools or heats the air inside the room.

The small pipe you can sometimes see that goes from the indoor unit through the wall to the outdoor unit only moves refrigerant and a small amount of moisture which is removed from the inside air during the cooling process, not fresh air.