01Cooling & heating
Evaporative Systems
Fresh air, cooled by water, for the whole house.
Bring fresh, cooled outside air into your Kalgoorlie home with an evaporative cooling system supplied and installed by BAH.
Evaporative cooling
How evaporative cooling works
A cooler on the roof draws hot outside air through water-soaked pads. As the water evaporates it soaks up heat, so the air leaving the pads is noticeably cooler — and a little more humid.
A fan then pushes that cooled, fresh air through ducts to outlets in each room, while a few windows or doors left ajar let the warm indoor air escape. Nothing is recirculated: the house is flushed with fresh air all day.
The drier the outside air, the bigger the cooling effect. That is why it suits Kalgoorlie: Bureau of Meteorology averages put January afternoons at around 24% relative humidity.
Good for
- Whole-of-home cooling with constant fresh air
- Hot, dry Goldfields days — the drier it is, the better it works
- Lower running costs than refrigerated cooling (government energy guidance)
- Households that like a breeze and windows open
Worth knowing
- Some windows or doors need to be left slightly open for it to work
- Less effective on humid days, such as after summer storms
- Uses water — pads must stay wet and some water is bled off to control minerals
- Cooling only: pair it with ducted gas heating or reverse cycle for winter
- Needs an annual service (City of Kalgoorlie-Boulder advice)
Try it
Will evaporative cooling work today?
Slide in the outside temperature and humidity to estimate the air an evaporative cooler would deliver — the drier the day, the bigger the drop.
Air leaving a typical evaporative cooler
21–24°C
Up to 13° cooler than outside
Excellent conditions for evaporative cooling
Physics estimate only: wet-bulb temperature by Stull’s (2011) formula, with coolers assumed to reach 70–90% of the wet-bulb depression. Real results depend on the cooler, pads, airflow, ducting and the home. Default values are Bureau of Meteorology long-term January averages for Kalgoorlie-Boulder; the other presets are illustrative.
Questions
Good questions
Can't see yours? Call the shop on (08) 9021 1744.
Guidance sources
- Bureau of Meteorology climate averages for Kalgoorlie (Wikipedia climate table) (opens in a new tab)
- ACT Government — Cooling for your home (opens in a new tab)
- City of Kalgoorlie-Boulder — Evaporative air conditioning fact sheet (opens in a new tab)
- WA Government media statement — Goldfields evaporative air conditioner water use (2020) (opens in a new tab)
Does evaporative cooling work in Kalgoorlie's climate?
Evaporative coolers work best in hot, dry air, which is what Kalgoorlie gets for most of summer — long-term Bureau of Meteorology averages put January afternoon humidity at around 24%. They are less effective on the occasional humid day, when refrigerated systems hold their output better.
Do I need to leave windows open?
Yes, a little. Evaporative systems push fresh air in, so the warm indoor air needs somewhere to go. Leaving a few windows or doors slightly open, ideally on the far side of the rooms you want cool, lets the cooled air flow through.
How much water does an evaporative cooler use?
It depends mostly on how long you run it. A 2020 WA Government statement on Goldfields water use said that in hot weather these systems need up to 20 litres an hour to keep the pads clean, and many use more. Correct bleed or dump-valve settings and regular servicing keep usage in check.
How often should it be serviced?
The City of Kalgoorlie-Boulder advises that all evaporative air conditioners need an annual service. Booking it before summer means the pads, pump, water levels and drainage are sorted before the first hot spell.
Evaporative cooling
Need a quote?
Tell us about your property and we'll come back to you about evaporative cooling. Your service is already selected below.
- Est. 1959, family owned
- EC 005983
- ARC AU07294
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