Should You Turn Off the Air Conditioner When Leaving for 30 Minutes? The Answer Isn’t as Simple as It Seems

Air conditioners are widely used during summer, offering faster and more efficient cooling than fans. While they seem easy to operate—just switch on/off or adjust settings via remote—many people unknowingly misuse their ACs, especially when it comes to turning the unit off and on.

A common question is:
If your room is already cooled and you need to leave for just 20–30 minutes, should you turn off the air conditioner to save electricity, or keep it running to maintain a comfortable temperature?

Here’s what experts say:

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Expert Advice

According to manufacturers, if you're only leaving the room for a short period (under 1 hour), you should NOT turn off the air conditioner, especially if you’re using an inverter AC.

Why not?

Experts explain that every time you restart your air conditioner, it needs to operate at maximum power to quickly bring the room back to the set temperature.
This startup phase is when the AC consumes the most electricity.

Research shows that during startup, an AC can use up to three times more energy than it does during normal operation.
Aside from wasting electricity, frequently turning the AC off and on in short intervals can shorten the device’s lifespan, especially affecting the compressor and motor systems. In extreme cases, it may even cause short circuits or equipment failure.

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What’s the Best Practice?

If you're stepping out for less than an hour and plan to continue using the AC upon return, but still want to save energy:

• Raise the AC temperature to around 28°C (82°F)

• Lower the fan speed

This allows the unit to operate at low power, minimizing energy waste while keeping the room cool.

However, if you plan to be out for more than an hour, it’s best to:

• Turn off the circuit breaker (or unplug the unit)
  This saves energy and prevents potential damage during long periods of non-use.

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When Should You Leave After Turning Off the AC?

Another often-overlooked detail: how soon should you leave the room after turning off the AC?

Many people have the habit of switching off the AC and immediately stepping outside—especially in the morning rush or midday heat.
But doing this can pose a health risk and reduce the effectiveness of your AC usage.

The Science Behind It

Medical experts warn that sudden temperature shifts can cause heat shock—a disruption in your body’s temperature regulation due to abrupt changes between cool indoor air and hot outdoor conditions.

When you're in an air-conditioned room, blood vessels near your skin constrict to conserve heat.
If you suddenly step into intense outdoor heat (often exceeding 37–40°C/99–104°F in summer), your body doesn't have enough time to adjust, potentially causing:

• Dizziness

• Light-headedness

• Shortness of breath

• Fatigue

• Disorientation

• In severe cases: fainting or even coma

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How to Transition Safely from Cool to Hot Environments

To allow your body to adapt:

• Turn off the AC 10–30 minutes before leaving
  (Adjust based on room and outdoor temperature.)

• Open a window or door to gradually let warm air in

• Wash your face or drink water to help hydrate and regulate body temperature

This gradual transition reduces the temperature gap between inside and outside, preventing sudden shocks to your system and helping you avoid issues like dry throat, nose discomfort, or heat exhaustion.

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Bottom Line:
If you're leaving for a short time, don’t rush to turn off your air conditioner—it may cost more energy and reduce the unit’s lifespan.
And if you're stepping outside from a cooled room, give your body a little time to adjust. It’s a simple step that can make a big difference to both your health and your energy bill.