Evaporative Cooling vs Refrigerated Air Conditioning

Two different ways of cooling a house

Evaporative cooling pulls outside air through wet pads and pushes cooler, slightly moister air through the house, which has to stay partly open so the air can escape. Refrigerated air conditioning (ducted reverse cycle, split and multi-head systems) removes heat from the air inside a closed house using a refrigerant circuit. They feel different, cost different amounts to run, and suit different homes and different people.

Where evaporative cooling wins

• Running cost. The main electrical load is a fan and a small pump, so running cost is low compared with refrigerated cooling.
• Fresh air. The house is open and the air is constantly replaced. Many people prefer the feel of it.
• Dry heat. On the hot, dry days the Ranges gets through summer, a well set up evaporative cooler is very effective.
• Simplicity. One unit on the roof, ducts and outlets, a simple controller.

Where refrigerated cooling wins

• Humid days. Evaporation slows when the air is already moist, so evaporative cooling gives less relief on humid days. Refrigerated cooling does not care.
• Precise temperature. A refrigerated system holds a set temperature in a closed house.
• Heating as well. A reverse cycle system heats in winter and cools in summer from the same equipment, which is why it is the usual choice for gas to electric conversions.
• Closed house. If you want windows shut for security, noise, pollen or bushfire smoke, refrigerated cooling is the only option that works that way.

Installation and cost

An evaporative cooler is generally the lower-cost cooling installation. A ducted reverse cycle system is a larger investment, because it is a whole-home heating and cooling system with new insulated ductwork, zoning and a more complex outdoor and indoor installation. Splits sit in between and scale with the number of rooms. We give written quotes after a site assessment rather than ranges from a website.

Running an evaporative cooler well

A lot of “my evaporative cooler is useless” comes from how it is used: switched on too late, too many windows open, the wrong side of the house open into the wind, or cooling mode on a humid day. Our guide to using evaporative cooling properly covers it.

Which suits which home

• Dry summers, a family happy to run the house open, running cost a priority: evaporative.
• Humid-day comfort, closed house, heating from the same system, zoning: refrigerated, usually ducted reverse cycle.
• A couple of rooms only: a split system, or a multi-head system for several rooms.

Some homes run both: an existing evaporative cooler kept for the dry days alongside a new reverse cycle system. Whether that makes sense depends on the roof and the design; see keeping the evaporative cooler when going electric.

Talk it through

We service, repair, replace and install both. Tell us how you use the house and we will give you a straight answer on which one suits it: evaporative cooling or ducted reverse cycle.