It's one of those questions that divide families in the summer. One person says to turn it off as soon as the room is cool, while another swears that leaving it on consumes less energy. The truth: it depends on how long you're away and what type of air conditioner you have. There is no fixed rule that applies to everyone. Let's see how to think about it so the bill really adds up.
Why the answer isn't always the same
An air conditioner consumes more when it has to lower the temperature from zero, that is, when it starts and has to cool a hot room. Once the temperature is reached, maintaining it costs much less. So turning it on and off continuously forces the machine to make a big effort each time. But leaving it on empty in an empty house for hours is money wasted. The right balance is somewhere in between.
When it’s worth leaving it on
- If you’re out for a short time. For an absence of an hour or two, turning it off and on costs more than keeping it running. The room heats up and then has to be cooled again.
- If you have an inverter model. Inverters slow down on their own when the room is at temperature, consuming very little to maintain it. They are designed to stay on for long periods.
- On very hot days. With 35 degrees outside, cooling down a hot room again costs a lot. Better to maintain the temperature.
When it’s worth turning it off
- If you’re out for many hours. Going to work and coming back in the evening? Turn it off. It makes no sense to cool empty rooms all day.
- If you have an old on-off model. Non-inverter models run at full power or are off, with no middle ground. Keeping them on for long periods costs more.
- At night with openable windows. If the outside temperature drops below 24 degrees, sometimes just opening the windows and turning it off is enough.
Tricks that matter more than on or off
The real difference is made by other things. Set the thermostat to 26 degrees instead of 22, because each degree lower adds about 6 percent more consumption. Use the timer to turn it on half an hour before you return instead of running it empty. Keep shutters and curtains down during sunny hours so the room doesn’t heat up. And clean the filters every two or three weeks, because dirty filters make it consume more for the same freshness.
The choice of device makes a difference
This whole discussion changes a lot depending on the technology. With an A+++ class inverter air conditioner, the on or off problem almost disappears because the machine self-regulates and maintains the temperature with minimal consumption. If you’re still considering options, it’s best to start here: take a look at our low-consumption air conditioners and choose based on the square meters of the room.
Frequently Asked Questions
Does turning the air conditioner off and on consume more?
Yes, each restart requires the greatest effort to bring the room back to temperature. For short absences, it’s better to leave it on; for long absences, it’s better to turn it off.
What temperature is best to keep the air conditioner at in summer?
Around 26 degrees is the best compromise between comfort and consumption. The practical rule is never to go more than 6 or 7 degrees below the outside temperature.
Is it worth keeping an inverter air conditioner on all day?
If someone is at home, yes, because it maintains the temperature while consuming very little. If the house remains empty for many hours, turning it off is still the most convenient choice.