Sometimes, but there is no single electricity-use figure for every window AC. Consumption depends on the unit’s input power and how long it runs. For a useful U.S. comparison, the Department of Energy’s 2024 guidance estimates 612 kWh per year for an example ENERGY STAR room air conditioner and 826 kWh per year for a less-efficient example. Both figures assume a 12,000 Btu/h unit operating 750 hours annually; they are standardized comparison figures, not a prediction of your household’s use.
How much electricity does a window air conditioner use?
Window AC electricity use varies with the model and its operating conditions. Cooling capacity alone does not tell you how much energy a unit will consume: input power and operating time matter too. Thermostat setting, outdoor weather, the room, and how often the compressor cycles all affect runtime.
The U.S. Department of Energy’s Federal Energy Management Program (FEMP) offers a comparison for a 12,000 Btu/h room air conditioner running 750 hours per year:
| FEMP example | Annual energy use | Assumption |
|---|---|---|
| ENERGY STAR model | 612 kWh/year | 12,000 Btu/h; 750 operating hours/year |
| Less-efficient model | 826 kWh/year | 12,000 Btu/h; 750 operating hours/year |
These are illustrative figures published in FEMP guidance updated in December 2024. They help compare examples under stated assumptions, but do not establish what a particular home will use.
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- PERFECT FOR SMALLER ROOMS - Midea's Affordable Window AC unit is perfect to help your room be as comfortable as possible. It can cool 150 sq. ft. with 7 temperature settings, 2 cooling/2 fan-only speeds, and 2-way air direction to give you the perfect amount of cooling every time.
- ENERGY EFFICIENT- Midea's 5,000 BTU window air conditioner has a Combined Energy Efficiency Rate (CEER) of 11.0 which helps reduce the energy costs to save you money throughout the year.
- QUIET & EASY TO USE - This window AC unit is quieter than a household refrigerator. It also features easy-to-use mechanical controls to quickly set the time, temperature, and mode and has a removable & reusable air filter.
- EASY INSTALLATION - Easily install in your home or apartment's existing window frame. Suitable for windows 23''-36'' wide and minimum 13'' high. All mounting accessories are included. A screwdriver is required (but not included) for installation. For some window frames, pilot holes are recommended before installing screws. Please see included instruction manual for further detail.
- WARRANTY: 1 Year Parts & Labor Warranty comes with each Midea product to ensure the quality of our brand to our customers. Our team is happy to help if any questions or issues arise and make sure to register your product on our website for even faster support in the future.
How much does it cost to run a window AC?
Estimate the cost by multiplying the energy used in kilowatt-hours (kWh) by your electricity price per kWh:
Energy (kWh) = input power (kW) × operating hours
Cost = energy (kWh) × your electricity price per kWh
For an estimate, find the unit’s rated input power in its product documentation, estimate how many hours it will actually operate, then use the per-kWh rate on your electricity bill. If you know annual kWh from a comparable product listing or official estimate, multiply that by your rate to estimate annual energy cost.
Rank #2
- BEST FOR SMALL ROOMS: Cools up to 150 sq ft efficiently with 5,000 BTU cooling power. Ideal for bedrooms, home offices, dorm rooms, workshops, and studio apartments. Compact 16.4" W x 13.4" D x 12.6" H design fits tight spaces.
- QUIET OPERATION - Quieter than many older window AC units, with 2 cooling modes (low 52 dBA for nighttime, high 56 dBA for rapid cooling) and 2 fan speeds for personalized comfort. Simple mechanical controls mean no annoying digital beeps.
- SIMPLE, RELIABLE MECHANICAL CONTROLS: Easy-to-use dials for temperature and fan speed—no Wi-Fi, apps or complex setup required. 10 temperature settings let you dial in your perfect comfort level. Auto restart after power outages.
- LOW MAINTENANCE & ENERGY SMART: No manual draining under normal conditions. Washable, reusable filter for easy care. Low 440W power draw helps reduce energy costs compared to older, inefficient units.
- EASY DIY INSTALLATION: Fixed chassis installs easily and fits double-hung windows 27.125"–36" wide and 13.375" high minimum. EZ Mount kit with foam insulation included. Backed by 1-year GE limited warranty for peace of mind.
FEMP’s illustrative cost calculation assumes 11.1 cents per kWh, based on federal-facility electricity data as of July 2024. That is an assumption for its example, not a typical or guaranteed household rate. Your bill’s applicable rate and the unit’s actual runtime determine your cost.
How can you compare window AC efficiency?
When comparing room air conditioners, match products with similar cooling capacity and type where possible. Check the Combined Energy Efficiency Ratio (CEER), annual energy use, and exact model number rather than relying on capacity or an ENERGY STAR label alone.
- CEER: A combined efficiency measure used in ENERGY STAR criteria and product listings.
- Annual kWh: A useful comparison only when the products and assumptions are comparable; it is not a promise of your household’s consumption.
- Cooling capacity: Compare Btu/h so you are not weighing models intended for materially different cooling needs.
- Your expected runtime and electricity rate: Use these to translate product figures into a household cost estimate.
- Certification and model number: Check the current listing for the precise model, since product listings can change.
ENERGY STAR says qualifying room air conditioners are 19–36% more energy efficient than minimum federal standards, depending on product category. That category-dependent comparison does not mean every certified unit will save that percentage against a particular older appliance. See ENERGY STAR’s room air conditioner criteria.
Rank #3
- Effortless Cooling: Achieve optimal comfort with customizable temperature settings and two fan speeds; Effortless Temperature Control helps to maintain your preset temperatures for consistent comfort
- Easy Maintenance: Keep your air conditioner running efficiently with the easy-to-clean washable filter, designed to capture dust from the air for long-lasting performance
- Undisturbed Comfort: Experience a peaceful home environment with a quiet performance at 52 dBA – ideal for bedrooms or small spaces up to 150 sq. ft.
- Effortless Convenience: Benefit from the Auto Restart feature, which automatically restores the unit's previous settings once power is restored to the window air conditioner
- Hassle-Free Operation: The extra-long three-prong power cord eliminates the need for extension cords, while the adjustable side panels easily extend to best fit your window, ensuring a secure installation with optimal efficiency and airflow
ENERGY STAR’s live Most Efficient results include listed 12,000 Btu/h window models with CEER 16.0 and annual use of 562.5 kWh. Those are model-specific values in a changeable listing, not a universal annual-use figure or guarantee of future availability. Check the exact product in the ENERGY STAR Most Efficient room air conditioner results.
Independent reader supportYour contribution helps us test, update, and keep practical guides available for everyone.Does ENERGY STAR mean a window AC will use little electricity?
Certification indicates that a product meets a defined efficiency threshold; it does not by itself determine your electricity bill. Your result still depends on the unit’s capacity and input power, how long it runs, room and weather conditions, and your local electricity rate. The Department of Energy treats room air conditioners, including window units, as a separate product category with its own guidance and criteria. FEMP’s room air conditioner purchasing guidance explains its comparison assumptions and efficiency information.
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What do federal efficiency-standard savings figures mean?
In a March 23, 2023 announcement about finalized standards for room air conditioners and portable air cleaners, the U.S. Department of Energy projected approximately $1.5 billion per year in consumer electricity-bill savings and 106 million metric tons of CO₂ emissions reductions over 30 years. These are aggregate projections for the standards, not a forecast of savings for an individual household. The figures are in the DOE announcement on the finalized efficiency rules.
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