Skip to main content

Evaporative Cooling

ENERGY | Heating and Cooling

What is evaporative cooling?

Evaporative cooling units pass warm air through a wet filter, which cools the air as the water evaporates. This cool air is then distributed throughout the building.

Evaporative cooling is very efficient, the only energy required is to power the fan that moves the air over the evaporator and a pump that moves the water. Evaporative systems, however, can use substantial amounts of water – 10 to 30 litres per hour depending on the size and air humidity.

Evaporative cooling systems are available as ducted or single room systems. A ducted system is installed outside, either on the roof or at ground level, in an area with good air flow.

Cross section of evaporative cooling system

Evaporative cooling in coastal locations

Coastal locations (i.e. eastern Sydney) are not generally suitable for evaporative cooling systems as the humidity can be too high and the system will not operate effectively.

Evaporative coolers will reduce air temperature by approximately 80% of the difference between the dry and wet bulb temperature.

If it is hot and humid, the gap between the dry and wet bulb temperatures is small and the cooler will not be able to lower the temperature of the air by much.

For these reasons, BASIX accepts and awards points for evaporative cooling in appropriate areas (generally non-coastal) e.g., Western Sydney.

If evaporative cooling is selected in BASIX in a postcode where evaporative cooling is not suitable a validation message will be triggered, requiring a change in cooling system selection before the BASIX certificate can be generated.

Last updated: 21/09/2023