I believe this is for an evaporative cooler, also known as a swamp cooler. Evaporative coolers only work in hot, dry climates -- given that Perth is in Western Australia I suspect this house would qualify. (I also found a few installers in Perth to confirm this: one, two, three.)
Then I found a few different evaporative cooler manuals which mention some of the things indicated on that control board -- here's one example, from a Seeley International manual:
- "The WaterManager™ allows you to specify either high or low salinity settings."
- "Manual mode will allow you to change settings for operating the cooler, such as altering fan speeds, pump control and manual drain control."
This fits given the controller settings, the geographic location, and the location of the wire running to the roof. It's possible that a newer cooler was installed and this controller was abandoned in place. The large IC with the red sticker looks like an old through-hole ASIC. A newer controller would probably use an SMD, and likely wouldn't have the functions in this board in a separate enclosure from the display or keypad.