Most people don’t realise how much small, everyday habits affect their aircon’s performance and their electricity bill. None of these mistakes are dramatic on their own, but together they can add hundreds of ringgit a year in wasted energy and avoidable repairs. Here are the five most common ones we see across homes and offices in Kuala Lumpur and Selangor — and what to do instead.
Mistake 1: Setting the Temperature Too Low
Setting your aircon to 18°C doesn’t cool the room faster — it just makes the compressor work harder and longer to reach a temperature you probably don’t need. Most homes are comfortable at 24–25°C, and every degree lower can noticeably increase energy consumption.
What to do instead: Set it to 24–25°C and use the fan mode or a ceiling fan alongside it to circulate cool air more evenly, rather than chasing a lower number.
Mistake 2: Ignoring the Filter for Months
A dirty filter restricts airflow, forcing your unit to run longer to reach the set temperature. This is one of the simplest things to prevent, yet it’s the most commonly skipped.
What to do instead: Rinse the filter yourself every 2–4 weeks if the unit runs daily. It takes a few minutes and makes a real difference to both cooling speed and energy use. Combine this with a proper chemical wash every 6 months to clean what a filter rinse can’t reach.
Mistake 3: Closing Vents or Blocking Airflow
Placing furniture in front of the indoor unit, or closing vents to “save energy” in one area, actually forces the system to work harder overall and can cause uneven cooling or even icing on the coil from restricted airflow.
What to do instead: Keep at least a metre of clearance in front of and around the indoor unit, and avoid blocking the outdoor condenser with stored items, plants, or laundry racks.
Mistake 4: Waiting Until It Breaks Down to Call for Service
Many people only think about their aircon when it stops cooling completely — but by that point, the issue has often been building for months, and the eventual repair is more expensive than routine maintenance would have been.
What to do instead: Stick to a regular maintenance schedule rather than a reactive one. Catching a small refrigerant leak or a worn capacitor early is far cheaper than waiting for a full breakdown.
Mistake 5: Constantly Switching the Unit On and Off
Turning the aircon off whenever you leave the room “to save power,” then switching it back on later, often uses more energy overall than leaving it running at a slightly higher, steady temperature. Every restart requires the compressor to draw a surge of power to get going again.
What to do instead: If you’re leaving for more than an hour or two, turning it off makes sense. But for short breaks, it’s usually more efficient to raise the temperature a couple of degrees rather than switching the unit off entirely.
Bonus: Not Knowing When to Call a Professional
Trying to fix electrical issues, refrigerant leaks, or persistent leaking yourself without the right tools can turn a small, inexpensive fix into a bigger repair. If you’re seeing signs that point to repair rather than cleaning, it’s worth getting a proper diagnosis early rather than guessing.
How Much Could These Mistakes Be Costing You?
While it varies by household, combining even two or three of these habits — running at 18°C, a dirty filter, and reactive-only servicing — can meaningfully increase your monthly electricity bill compared to a well-maintained system running efficiently. Small, consistent habits add up to real savings over a year.
Frequently Asked Questions
Does turning my aircon off during the day and back on at night save money? Not necessarily. If you’re away for just a few hours, leaving it at a higher temperature setting is often more efficient than a full shutdown and restart, due to the power surge each restart requires.
How much colder does 18°C actually make a room compared to 24°C? The room doesn’t cool faster at a lower setting — the unit runs the same way until it reaches the target temperature, it just keeps running longer to reach an unnecessarily low number, using more energy in the process.
Can a dirty filter actually damage my aircon over time? Yes. A persistently restricted airflow forces the compressor to work harder for longer, which accelerates wear and can shorten the unit’s overall lifespan.
Is it bad to block the outdoor condenser unit with storage items? Yes, this restricts airflow around the condenser, reducing efficiency and potentially causing the system to overheat during extended use.
How do I know if my energy bill increase is due to my aircon habits or an actual fault? If you’ve addressed habits like temperature settings and filter cleaning but bills remain high, it’s worth booking a maintenance check to rule out refrigerant loss or a mechanical fault.
Keep Your Aircon Running Efficiently
Small habit changes help, but nothing replaces regular professional servicing to catch the issues you can’t see yourself. Message us on WhatsApp to book a maintenance check, call +60 10-593 0730, or check our price list for service rates across Kuala Lumpur and Selangor.