How evaporative cooling works
An evaporative cooler draws hot outside air through water-soaked pads. As the water evaporates it absorbs heat, so the air leaving the pads is noticeably cooler. A fan then pushes that air through ducts into the house, and the warm stale air leaves through open windows or doors. There is no compressor and no refrigerant gas, which is why running costs are low compared with refrigerated air conditioning.
The cooler cabinet usually sits outside, high on the building, and feeds ducts in the ceiling space. Wall-mounted and portable versions exist for smaller spaces, sheds and workshops.
Where it works, and where it doesn't
Evaporative cooling depends on dry air. The lower the humidity, the more water can evaporate and the cooler the supply air. That makes it a good match for much of inland Australia, where summer heat tends to be dry.
On humid days the effect drops off, and in the tropical north or on sticky coastal days it may feel more like a fan than an air conditioner. If your summers are muggy, refrigerated cooling is the better investment, and we will tell you that before you buy anything.
Open a window. Evaporative systems need somewhere for air to go. Leaving windows or doors open a little in the rooms you want cooled is what makes the system work, which also means a steady flow of fresh air through the house.
Our evaporative services
- New installations including cooler sizing, ducting design, outlet placement and a dedicated water and power supply.
- Replacements of tired or leaking units, reusing sound ductwork where it suits the new cooler.
- Seasonal start-up in spring: pad inspection, water distribution check, float valve, pump and drain test.
- End-of-season shut-down in autumn: draining, cleaning and fitting winter covers to stop draughts and heat loss through the outlets.
- Repairs to pumps, motors, float valves, controllers and leaking trays.
How a service visit runs
- Isolate power and water, then open the cabinet and inspect the pads for scale, clogging or damage.
- Clean the water tray, check the pump, distribution lines and float valve, and flush the system.
- Inspect the fan, motor and belts (where fitted), plus the controller and wiring.
- Check the drain or bleed-off so mineral build-up doesn't shorten pad life.
- Run the cooler, confirm airflow at the outlets and note anything that needs attention later.
Keeping it healthy
Because evaporative coolers hold water, regular maintenance matters for both performance and hygiene. A unit that sits full of stagnant water through winter can smell musty when it starts up. Draining it at the end of the season, cleaning it at the start of the next, and replacing pads when they become crusted with minerals keeps the air fresh and the cooler efficient.
Questions we hear about evaporative cooling
Is evaporative cheaper to run than refrigerated air?
Generally yes, because it uses a fan and a small water pump instead of a compressor. It does use water, so expect some water usage on hot days.
Can I use evaporative cooling with the windows shut?
No. Without an exit for the air, humidity builds up indoors and the cooling stops working. Keep windows or doors open slightly in the rooms you are cooling.
How often should pads be replaced?
It depends on water quality and how hard the cooler works. Pads that are crusted, crumbling or smell musty are due. We check them at every service.
Does evaporative cooling heat in winter?
No, evaporative is cooling only. Many households pair it with reverse-cycle split systems or ducted heating for the colder months.