Evaporative Coolers

Advantages

Evaporative coolers take outside air, condition it and blow it into your home via ceiling ducts. This can be very pleasant on a mild day, as you can use the cooler on the fan only function to blow fresh air inside. 

Unlike ducted systems listed above, evaporative coolers can be less than half the price to install. If you’re the type of person who likes your doors and windows open in Summer, evaporative coolers are worth considering. They are a basic machine, being mainly a water pump and a fan motor and are therefore the cheapest type of cooling to run.

Disadvantages

You must have windows open for these units to operate effectively, some people prefer to have windows closed in Summer.

These units can only reach 10 – 12 degrees difference from outside. If it is a 40 degree day the best you can hope for inside is approx. 28 degrees.

They are usually much louder than a ducted split system due to the amount of air they push inside the home.
If there is smoke outside (think smoke haze January 2020 from the bushfires) it is best not to use your cooler as it will be blown inside. This effectively means you will have no cooling for this period.

Evaporative coolers are less effective on humid days.  Evaporative cooler operation adds moisture, or humidity to the air.  This can be both an advantage or a disadvantage, depending upon circumstances.