The fastest way to reduce your AC electricity bill is to cut the kilowatt-hours your unit uses: raise the thermostat to 24-26°C (75-78°F), run the AC fewer hours, and choose an inverter model when you replace it.
Your bill is kWh multiplied by your tariff, and kWh is your AC’s power draw multiplied by its running hours, so every saving below comes down to those two numbers.
The sections ahead convert common tips into kWh, explain why per-degree savings claims disagree, and settle whether to leave the AC on or switch it off.
AC tips to reduce Electricity Bill: what are the fastest ways?
The fastest AC tips to reduce your electricity bill are a higher setpoint, fewer running hours, a fan, shaded windows, and a clean filter. Each one cuts either the power your AC draws or the hours it runs.
How do I make my AC use less electricity?
- Raise the setpoint to 24-26°C (75-78°F). From our installation and maintenance experience with various AC brands, you can save roughly 2-3% of cooling energy per degree.
- Cut running hours. One hour less in an eight-hour day trims monthly runtime by 12.5%, usually more than one degree of setpoint saves.
- Add a fan. It lets you accept a higher setpoint, but it cools people, not the room, so switch it off when nobody is there.
- Close curtains or blinds on sunny windows during the hottest hours.
- Clean the filter. Several manufacturer and utility blogs say a dirty one adds 5-15% to energy use, though none names the study.
- Choose an inverter model when you replace the unit.
Ways to reduce electricity bill beyond the AC
There are other ways you can reduce your electricity bill beyond monitoring or switching off your air conditioner; below are our recommendations:
- In my home, when other electrical appliances are not in use, like the TV, chargers, or other slightly heavy home appliances, I completely switch them off rather than leaving them on standby.
- On an off-peak tariff, I run the washing machine and other heavy appliances in the cheaper hours.
- I inform my wife to skip the oven during the hottest hours, since its heat lengthens our AC’s run time.
How much electricity does an air conditioner use?
We can’t discuss how to reduce your Air conditioner electricity bill without understanding how much electricity your air conditioner consumes or uses.
For starters, a split-type inverter AC typically uses about 0.25-0.75 kWh per hour while holding temperature, while a central system uses 3,000-3,500 watts.
However, your own figure depends on size, type, setpoint, and hours, so calculate it rather than trusting averages.
How to calculate your AC running cost
Monthly cost = kW × hours per day × days × tariff per kWh.
- Find your AC’s watts on the nameplate or spec sheet and divide by 1,000 to get kW.
- Estimate the hours it runs each day.
- Multiply kW by daily hours by 30 for monthly kWh.
- Multiply by the rate on your electricity bill.
We have discussed this in detail in this comprehensive guide: Air conditioner Electricity usage by Types.
| Unit | Power draw | Monthly kWh | Monthly cost at $0.15/kWh |
|---|---|---|---|
| 0.8 HP inverter (average draw) | 700 W | 168 | $25.20 |
| Comparable non-inverter | 1,100 W | 264 | $39.60 |
Nameplate watts show maximum draw, so for a truer number, read your electricity meter before and after one hour of AC use with other large appliances off.
This table converts common savings claims to kWh for the 1,100 W unit above (264 kWh a month):
| Action | Assumption | kWh saved per month | Saved at $0.15/kWh |
|---|---|---|---|
| Replace with the 700 W inverter | Same 8 hours a day | 96 | $14.40 |
| Run one hour less per day | 1.1 kWh × 30 days | 33 | $4.95 |
| Clean the filter | 5-15% claim, unverified | 13-40 | $1.98-$5.94 |
| Raise the setpoint one °F | About 3% of energy | 8 | $1.19 |
An hour less runtime saves about four times what one degree of setpoint does, which is why hours deserve attention first.
The AC running cost calculator applies the same arithmetic to your own watts, hours, and tariff.
kWh use by AC size and type
The table below shows an example of an AC run for 8 hours a day for 30 days:
| Unit type | kWh per hour | kWh per month |
|---|---|---|
| 0.75 HP inverter | 0.25-0.40 | 60-96 |
| 1.0 HP inverter | 0.35-0.55 | 84-132 |
| 1.5 HP inverter | 0.50-0.75 | 120-180 |
| 1.0 HP older non-inverter | 0.85-1.05 | 204-252 |
What is the best AC temperature to save electricity?
The best AC temperature to save electricity is 24-26°C (75-78°F). Some HVAC technicians recommend 25°C and 26°C.
How much does each degree save?
Each degree you raise the thermostat saves roughly 3% of cooling energy, though published figures run from 2% to 7%.
| Claim | Notes |
|---|---|
| Nearly 3% per degree raised | Degree unit not stated |
| About 2-3% per degree raised | Quoted against the overall bill |
| Up to 3% more per degree below 78°F | US utility |
| 3-5% less energy per degree higher | Degree unit not stated |
| Up to 7% more per degree lower | Starts from 26°C |
Most sources never say whether a degree means °F or °C, and 3% per °F works out to about 5.4% per °C, which would bring the US figures close to the European ones.
The percentages also apply to cooling energy, not the whole bill, so a 3% cut in an AC that makes up half your bill trims the bill by 1.5%.
A safe planning figure is 3% of cooling energy per °F, or about 5% per °C.
Best AC temperature for sleeping
- ENERGY STAR, a joint program of the U.S. Environmental Protection Agency and the U.S. Department of Energy, provides an example summer thermostat schedule of 78°F when awake at home, 85°F when away, and 82°F while sleeping; it describes these figures as a starting point that households should adjust for comfort.
- Use the timer to stop the AC after you fall asleep, since Most summer nights cool down enough to make overnight cooling unnecessary.
- Add a ceiling fan so a setpoint a degree or two higher still feels comfortable.
For setpoint and timer combinations by climate, see our guide to the best AC temperature for sleeping.
Why setting the AC to 18°C doesn’t cool faster
A lower setting does not cool the room faster, because the thermostat only tells the compressor when to stop.
In a fixed-speed AC, the compressor runs at full output until the room hits the target, whether that is 18°C or 25°C. A lower target only keeps it running longer.
Should you leave the AC on or turn it off?
Turn the AC off, or raise the thermostat well above normal, when you will be away about eight hours or more, because running it at a normal setting all day used more energy in the modeled cases.
For shorter absences, the gap is small, so the rule below weighs absence length and humidity.
Does keeping the AC on 24 hours save electricity?
No. Running the AC around the clock keeps removing heat during hours when no one is home.
Engineers at the University of Colorado Boulder used energy-modeling software developed by the National Renewable Energy Laboratory to compare air-conditioning strategies in a hypothetical 1,200-square-foot home in Arizona and Georgia.
They found that, although the air conditioner temporarily used more power to cool the home after an eight-hour setback, total energy consumption was still lower than when the system maintained a constant temperature throughout the day.
What the research found: 8 hours vs 4 hours
The Colorado team modeled a hypothetical 1,200 square foot (110 square meter) home.
| Absence | Result |
|---|---|
| 8 hours off | Saved energy with every system type |
| 4 hours off | Mixed: a small saving or slightly more energy than running all day, depending on humidity and system |
| 2 hours | Minimal difference between off and a raised setpoint |
| Days, fully off | More than half of homeowners who shut off completely used more energy on return. |
The Colorado team did not account for how clean the system was.
A decision rule by absence length
- Home all day? Keep a steady 24-26°C and leave it on.
- Out two hours or less? Keep your normal setting, since the difference is minimal.
- Out about four hours? Raise the setpoint several degrees rather than switching off, because results were mixed.
- Out eight hours or more? Switch it off, or set it well above normal in a very humid climate.
- Away for days? Raise the setpoint instead of shutting down, since many full shutdowns cost more on return.
AC on auto vs on: which fan setting saves power?
On central systems with a thermostat fan switch, Auto runs the indoor fan only while the system is cooling.
On keeps the fan running continuously, even while the compressor is idle. Auto uses less electricity, so choose On only if you need constant air circulation.
Inverter vs non-inverter AC: which costs less to run?
In an inverter vs non-inverter AC comparison, the inverter model costs less to run in every retailer example reviewed, using roughly 36-56% less electricity than a fixed-speed unit of the same size, though its higher price takes months to recover.
How each type controls the compressor
A fixed-speed (non-inverter) AC runs its compressor at full power until the room reaches the target, shuts it off, then restarts it when the room warms.
An inverter AC uses a variable-speed compressor that works like a dimmer switch: once the room is cool, it slows down to hold the temperature instead of cycling fully on and off.
Monthly running cost comparison
These are retailer examples, so read them as illustrations, not lab results.
| Example | Non-inverter kWh/month | Inverter kWh/month | Difference | Saving |
|---|---|---|---|---|
| 1.0 HP, 10 hours a day | 330 | 180 | 150 | 45% |
| 0.8 HP inverter vs comparable unit, 8 hours a day | 264 | 168 | 96 | 36% |
| 1.0 HP Hisense example, 10 hours a day | 270 | 120 | 150 | 56% |
One retailer brand says inverter technology saves 30-35% more energy than a standard AC, while another brand claims up to 60%. The only way to find out is to test it yourself.
Inverter AC payback period formula
- Subtract the non-inverter price from the inverter price to get the price gap.
- Multiply the monthly kWh difference by your tariff to get the monthly saving.
- Divide the price gap by the monthly saving to get months to break even.
With a 150 kWh monthly difference at an assumed $0.15 per kWh, the saving is $22.50 a month, so an inverter costing $270 more pays back in 12 months.
Based on that, inverters usually win when the AC runs six or more hours a day.
How to read star ratings, EER and SEER2
| Metric | What it measures | How to compare |
|---|---|---|
| Star rating | Efficiency grade from one to five stars; more stars mean lower bills | Same capacity, same label scheme |
| EER | Cooling delivered per unit of electricity; higher is better | Same cooling capacity |
| SEER2 | US seasonal efficiency under more realistic tests, in use since 2023 | Central AC minimums are 13.4 (North) and 14.3 (South and Southwest); SEER × 0.955 ≈ SEER2 |
How does AC maintenance reduce your electricity bill?
AC maintenance reduces your bill by keeping airflow clear so the compressor runs fewer hours.
Do clean filters really save 5-15%?
- Most HVAC companies agree that cleaning your air filters helps with a 5 – 15% reduction in saving your electricity costs because it reduces stress on the compressor by enhancing quick and easy cooling.
- We recommend that our clients periodically clean or replace damaged filters. For cleaning air filters, we recommend cleaning them once every three months or depending on use of the AC unit.
- Keep the outdoor unit clear of leaves and obstructions so heat can leave freely.
For cleaning steps, see how to clean an AC filter step by step.
How do you keep cool air in and heat out?
Keep cool air in by sealing leaks, shading windows, and using fans.
Seal leaks and insulate
- Air leaks divert cooled air and raise the monthly bill, so seal gaps around doors and windows.
- We recommend insulation to stop cool air escaping and hot air entering.
Shade windows during peak heat
- Closing blinds, shades, or curtains keeps the sun out and the cool air in.
- We advise keeping curtains and shutters closed in the hottest hours.
Use ceiling fans to raise the thermostat setting
Pair a ceiling fan with a setpoint one or two degrees higher.
Ceiling fans let you raise the thermostat without losing comfort, and fans cool people, not rooms, so turn them off when nobody is there.
For the cost comparison, see ceiling fan vs AC running cost.
Do timers and smart thermostats cut AC costs?
Yes. Timers cut AC costs by removing unneeded run time, and smart or programmable thermostats automate the same schedule. Both save money only when they remove hours or degrees.
AC timer and sleep mode
- Set the timer to stop the AC after you fall asleep, since most summer nights cool down enough that you do not need it overnight.
- If your plan has off-peak rates, check whether your AC schedule overlaps peak rates.
Smart and programmable thermostats
A smart thermostat can save money, and a programmable thermostat can raise the temperature when no one is home.
When is it worth replacing an old AC?
Replacing an old AC is worth it when repair costs approach 30-40% of a new unit’s price, or when an older fixed-speed unit runs many hours a day.
The repair-or-replace test
- Is the repair quote above 30-40% of a new system’s price? Then we recommend you get a new AC.
- Is the unit fixed-speed and running more than six hours a day? The payback formula above will likely favor an inverter.
- Has a major component failed on a legacy R-410A system?
- Is your bill climbing while usage stays steady? Clean the filter and apply the habits above first.
An oversized unit cools quickly and shuts off, which mimics a non-inverter. Before buying, check what size AC you need for your room.
What efficiency gain to expect
These US HVAC publisher figures vary with climate, run time, and duct leakage.
| Upgrade | Reported cooling-energy cut |
|---|---|
| 14 SEER2 to 17 SEER2 | About 15-20%, or $90-$120 a year on $600 of cooling |
| Minimum efficiency to 16 SEER2 | Roughly 15-25% |
| About 10 SEER to high SEER2 with variable-speed compressor | 30-50% |
How to reduce electricity bill in Nigeria
To reduce your electricity bill in Nigeria, apply the same kWh arithmetic to your own meter: cut your AC’s hours and setpoint, shade and seal the space, and track the result in units.
Other ways you can reduce your electricity bill are:
- Put off your lighting when it is day, on them only when needed and at night time
- Heavy home electrical appliances like the deep freezer: turn them off immediately when they are cold enough during the day, and turn them on later before bedtime.
- Standing fans consume less electricity than ceiling fans, except if you have an industrial fan at home, which is unlikely.
- We recommend new smart TVs like Hisense, as they consume less eletricity more than the old ones, like 5 years ago and beyond, no matter the brand.
- Use heavy equipment only and quickly when you immediately get (buy) a token for your prepaid meter; don’t use heavy home electrical equipment when the unit is about to finish.
How can you lower the electricity bill for your apartment?
- Cool only the room you are using and keep its door closed so the unit does not condition hallways.
- Use removable draft strips and closed curtains to cut heat gain without altering the building.
- Check your prepaid units before and after an AC session to see what each hour costs you.
Nigeria-specific factors: tariff bands, prepaid meters and backup power
| Factor | Why it matters for your AC bill | What to check |
|---|---|---|
| Tariff band | Distribution companies assign a band or class, so your rate per kWh can differ from a neighbor’s | Your current rate on the company’s published tariff |
| Prepaid meter | Units are deducted as you use power, so you can measure kWh directly | Units balance before and after one hour of AC use |
| Backup power | AC on a generator or inverter-battery setup costs a different amount per kWh than grid power | Fuel or battery cost per kWh for your setup |
Once you know your AC’s wattage, daily hours, and tariff, every change in this guide, from a higher setpoint to a timer or a more efficient unit, can be compared in money instead of percentages.
Run your own numbers in the AC running cost calculator before you change a setting.