08/10/2026
So, Should You Leave It On?
There’s no single right answer for every WA home. Here’s a practical way to think through the decision for yours, based on the variables covered so far in this series.
With all this technology and science, it would be reasonable to expect a straight answer by now: leave it on, or turn it off. The honest position is that there isn’t one answer, and anyone offering a single rule for every home, in either direction, is oversimplifying a decision that genuinely depends on the specifics of the house in question.
What’s more useful than a universal rule is knowing which questions actually decide it for your own home. Based on everything covered so far in this series, they come down to roughly five:
- How hot does the house realistically get by mid-afternoon, and how long does it take the system to recover once it’s switched on?
- Is the system zoned, or is it an all-or-nothing proposition across the whole home?
- Does the home have solar, and is there a meaningful gap between what it generates and what the household draws during the day?
- How well does the house ‘hold’ or ‘resist’ heat in the first place, insulation, shading, orientation before the air conditioner even gets involved?
- What time does everyone actually get home, and how much does walking into a cool house immediately matter to your household, versus being happy to wait twenty minutes?
Answer those honestly for your own home, and the decision tends to make itself. A well-shaded, well-insulated home with a small solar system and a single-zone unit probably still does best with the old rule of, off while empty, on when someone’s back. A larger home with generous solar, a zoned system and a household that values walking straight into comfort has a reasonable case for some pre-cooling, focused on the rooms that matter, timed around when people actually arrive.
Neither answer is more sophisticated than the other. They’re just suited to different homes.
NEXT IN THIS SERIES: The Future of the WA Home
1800 AIR CON 
