Owner Guide
How to Reduce Air Conditioner Running Costs
Want to reduce air conditioner running costs without giving up comfort? Most savings come from a handful of simple habits, a little maintenance and some attention to the home itself. This guide walks through what actually drives your energy use and the practical steps that make the biggest difference.
Where the Money Goes
What Drives Air Conditioner Running Costs?
Your air conditioner’s power bill comes down to two things. First, how much electricity the unit draws while it runs. Second, how many hours it runs. Almost every saving tip works by shrinking one or both of those numbers.
Power draw depends on the unit’s size, its efficiency and how hard it has to work. A system fighting a hot, sunny room with dirty filters works much harder than the same system in a shaded room with clean filters. Meanwhile, running hours depend on your habits, your schedule and how well your home holds its temperature.
Your electricity tariff also matters. Some households pay different rates at different times of day. If that applies to you, when you run the system can affect the bill as much as how long it runs.
The System
Size, age, efficiency rating and condition all shape how much power the unit needs to deliver comfort.
The Home
Insulation, windows, shading and draughts decide how quickly heat gets in during summer and escapes in winter.
The Habits
Temperature settings, scheduling, door closing and room choice determine how many hours the unit works.
To put your own numbers on this, try our air conditioning running costs calculator. It lets you test how changes to hours and usage might affect your bill.
Settings
Which Settings Help Lower Your Aircon Power Bill?
Small changes to settings can deliver steady savings over a whole season. The aim is to let the system work efficiently rather than flat out.
Choose a Moderate Set Temperature
Each degree closer to the outdoor temperature reduces the work the system must do. In summer, a slightly warmer setting saves energy. In winter, a slightly cooler setting does the same. Our best temperature settings guide covers suggested ranges in detail.
Avoid Extreme Settings for a Quick Result
Setting the lowest possible temperature does not cool the room faster. It only keeps the unit running longer and often overshoots, wasting energy and leaving the room too cold.
Use Auto Fan
Auto fan lets the system match airflow to demand. It runs harder when the room is far from the setting and eases off once it is comfortable.
Try Dry Mode on Muggy Days
On humid days that are not especially hot, dry mode can make a room feel comfortable by removing moisture. Many people find it a gentler option than full cooling in those conditions.
Use Eco or Economy Modes Where Available
Many brands include an energy saving mode that limits maximum output. Check your manual, and read our guide on air conditioner symbols to identify the right button.
Timing
Does When You Run the Air Conditioner Affect the Cost?
Timing matters in two ways. It affects how hard the unit must work, and it may affect the price you pay for each unit of electricity.
Starting the system before the house gets very hot usually means it can hold a comfortable temperature at a moderate output. By contrast, waiting until late afternoon, when walls and furniture have soaked up heat all day, forces the unit to work much harder for longer.
Use Timers and Schedules
A timer or app schedule can start the system shortly before you get home, rather than leaving it running all day. It can also switch it off once you are asleep, if the bedroom will stay comfortable overnight. Our air conditioner WiFi and app control guide explains how each brand’s app handles schedules.
Check Your Tariff
If you are on a time of use tariff, check when your peak, shoulder and off peak periods fall. Pre cooling or pre heating the home before a peak period starts can reduce the amount you pay. Your electricity retailer can explain your tariff structure.
Avoid Constant On and Off Switching
Turning a unit off every time you leave a room for a few minutes can be counterproductive, particularly with inverter systems. They are designed to settle at a low, steady output. Learn why in inverter air conditioners explained.
Your Home
How Can Your Home Help Cut Cooling and Heating Costs?
The less heat that enters your home in summer, and the less that escapes in winter, the less your air conditioner has to do. Some improvements cost nothing, while others are longer term investments.
Shade the Windows
Close blinds and curtains on sunny windows during summer, especially on the west side in the afternoon. External shading, such as awnings or outdoor blinds, stops heat before it reaches the glass.
Close Doors to Unused Rooms
Only condition the space you are using. Closing doors keeps conditioned air where it is needed and reduces the load on the system.
Seal Draughts
Gaps under doors, around windows and through old exhaust fans let conditioned air escape. Draught stoppers and seals are simple, low cost fixes.
Check the Insulation
Ceiling insulation is one of the most effective ways to reduce heat gain and loss. If your roof space has little or none, an insulation installer can advise on options.
Use Ceiling Fans Together
Ceiling fans move air across your skin, which can make a room feel cooler. Running a fan with the air conditioner may let you set a slightly warmer temperature in summer.
Ventilate When It Is Cooler Outside
On evenings when the outdoor air cools down, opening windows can flush heat from the house without running the air conditioner at all.
Maintenance
Can Maintenance Really Reduce Air Conditioner Running Costs?
Yes. A system that is clean and in good order moves heat more easily, which means it can reach and hold the set temperature with less effort. Neglected units, on the other hand, quietly waste energy every day they run.
- Clean split system filters every few weeks during heavy use
- Clean or replace the ducted return air filter regularly
- Keep plants, bins and clutter away from the outdoor unit
- Gently rinse leaves and dust from the outdoor coil fins, with power off
- Watch for ice, leaks or weak airflow and act early
- Book professional servicing on a regular schedule
Professional servicing covers parts you cannot safely reach. A technician cleans the indoor coil and blower wheel, flushes the drain, checks electrical connections and looks for early signs of refrigerant loss. Our article on how often you should service your AC explains suitable intervals, and our guide on how to clean air conditioner filters walks you through the filter job step by step.
What Faults Waste the Most Energy?
Several faults make a system run longer while delivering less comfort. A slow refrigerant leak is a common example. The unit keeps running but struggles to cool, and eventually ice may form. Read about ice on the outdoor unit and weak airflow if these symptoms sound familiar.
Warning Signs
What Signs Suggest Your System Is Wasting Energy?
Sometimes rising running costs point to a problem rather than a habit. Watch for these signs, because catching them early protects both your comfort and your bill.
Performance Clues
- The unit runs much longer than it used to
- Rooms never quite reach the set temperature
- Airflow from the vents or head feels weaker
- The system short cycles on and off frequently
- Humidity stays high even while cooling
- Warm air blowing in cooling mode
Physical Clues
- Ice on pipes or the outdoor unit
- Water leaking from the indoor unit
- Unusual noises from the fan or compressor
- A musty smell when the unit starts
- An error code on the display
- The safety switch tripping
If any of these appear, start with our air conditioner troubleshooting section. For warm air in cooling mode, see blowing warm air on cool. For a clammy feel, read high humidity and clammy rooms. Error codes are explained in our air conditioner error codes guide.
Winter Heating
How Do You Keep Heating Costs Down in Winter?
Reverse cycle air conditioning is a popular way to heat Australian homes. Many of the same principles apply in winter as in summer, although a few habits are specific to the colder months.
Dress for the Season
A jumper and warm socks let you set a slightly lower temperature without feeling cold. It sounds obvious, but it is one of the easiest savings available.
Let the Sun In
Open curtains on north facing windows during sunny winter days to capture free warmth. Close them once the sun goes down to hold the heat inside.
Expect Defrost Pauses
On cold, damp mornings, the outdoor unit periodically defrosts itself. Heating pauses briefly, which is normal. Resist turning the temperature up during these pauses.
Heat the Rooms You Use
Close doors to bedrooms and hallways during the day, then shift your heating to the bedrooms before bed. Warming the whole house all evening wastes energy.
If the unit blows cool air for long periods in heating mode, something may be wrong. Read air conditioner blowing cold air on heat to understand the likely causes.
Seasonal Routine
What Simple Seasonal Routine Keeps Costs in Check?
A short routine at the start of each season helps the system run efficiently from day one. Instead of waiting for a problem on the first heatwave or cold snap, take a few minutes to prepare.
Before summer, clean the filters, clear around the outdoor unit and test cooling on a mild day. That way, any fault shows up before demand peaks and technicians are busiest. Our guide on how to prepare your air conditioner for summer covers this in more detail.
Before winter, repeat the filter clean and test heating mode. Check that the outdoor unit is not sitting in long grass or piled leaves. Then, at the end of each season, note anything unusual, such as new noises or longer running times, and mention it at your next service.
Ducted Homes
How Can Ducted System Owners Save Energy?
Ducted systems offer whole home comfort, but they can also condition rooms nobody is using. A few ducted specific habits help keep costs in check.
Use Your Zones
Condition living areas during the day and bedrooms at night. Closing unused zones reduces the area the system must cool or heat.Keep the Return Air Grille Clear
Furniture or curtains blocking the return grille restrict airflow and make the system work harder.Clean the Return Air Filter
A clogged filter starves the whole system of air. Check it regularly, especially during long running seasons.Watch for Duct Problems
If one room is always warm, a disconnected or crushed duct may be leaking conditioned air into the roof space. See ducted one room not cooling.Check Zone Operation
A zone motor stuck open sends air to rooms you have closed off. Our guide to ducted zone not working explains the symptoms.
For a broader look at system types, read split system vs ducted air conditioning.
Older Units
When Does Upgrading Reduce Running Costs?
Sometimes the most effective saving is a newer, more efficient system. However, replacing a working unit purely to save energy does not always make financial sense. The decision depends on the age, condition and efficiency of your current system, and how much you use it.
Upgrading becomes more attractive when an older unit needs a major repair, uses a refrigerant that is being phased down, or is clearly the wrong size for the room. In those cases, a modern inverter system with a good energy rating can offer better comfort and lower running costs. Our guide on is it worth repairing an old AC helps you weigh up the choice.
Correct sizing is essential when replacing. An undersized unit runs flat out, while an oversized one short cycles. Read what size air conditioner do I need before choosing a replacement.
Do Brands Differ on Efficiency?
Every major brand offers efficient inverter models, along with more basic ranges. Compare the energy rating label on models of the same capacity rather than relying on brand reputation. For general brand information, see our pages on Daikin, Mitsubishi, Panasonic, Samsung, Fujitsu and LG. We are an independent booking service, not an authorised dealer for any brand.
Good to Know
What Else Helps Keep Running Costs Down?
Open the panel for a few extra tips that are easy to overlook.
Open more detail
Point the louvres sensibly. In cooling mode, direct air across the room rather than at the floor. In heating, angle it downward, because warm air rises naturally.
Keep heat sources in check. Ovens, dryers and halogen lights add heat. On hot days, cook outdoors or use the microwave where practical.
Do not block the indoor unit. Curtains, tall furniture or shelves too close to a split system head disrupt airflow and confuse the room sensor.
Watch the sensor location. Some units read room temperature from the remote or wall controller. Keep it out of direct sun and away from lamps.
Use the right system for the room. If you only need one room, run that room’s split system rather than the whole ducted system.
Reset rather than repeatedly restart. If the unit behaves oddly, our guide on how to reset common air conditioning faults yourself explains a safe reset.
Questions
Frequently Asked Questions
Is it cheaper to leave the air conditioner on all day?
Usually not when the house is empty. A schedule that starts the system shortly before you arrive home is often a better balance than either running all day or switching on only when the house is very hot.
How can I estimate my running costs?
Use our air conditioning running costs calculator. It uses your unit details, hours and electricity rate to give an estimate.
Does cleaning filters really save money?
Clean filters let air flow freely, so the system can reach the set temperature more easily. It is one of the simplest and cheapest maintenance tasks you can do.
Do ceiling fans help reduce costs?
Ceiling fans can make a room feel cooler, which may let you set a slightly warmer temperature in summer. They use far less power than an air conditioner.
Why has my bill gone up suddenly?
Hotter weather, changed habits or a tariff change are common causes. A developing fault, such as low refrigerant or dirty coils, can also increase running time. Book a check if performance has dropped.
Is a bigger unit cheaper to run?
Not necessarily. A correctly sized unit runs most efficiently. Oversized units can short cycle, while undersized ones run flat out for long periods.
Who can service my system?
We book licensed technicians nationally, including air conditioner repairs Sydney and air conditioner repairs Perth.
Keep Reading
Where Can You Find More Owner Guides?
Explore all our air conditioner owner guides, or return to our air conditioning service Australia homepage. If your system is underperforming, book a technician in your city.
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Is Your System Costing More Than It Should?
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Reviewed by AC repair and service specialist on 22 October 2026. How we write our articles