Window air conditioner vs. mini split air conditioner: running cost
A window air conditioner is cheaper to run: about $74 a year versus $110 for a mini split air conditioner at typical use and 17.99¢/kWh, a $36 difference.
| Window air conditioner | Mini split air conditioner | |
|---|---|---|
| Typical watts | 700 W | 900 W |
| Watt range | 400–1,800 W | 300–2,500 W |
| Typical use | 8 hours a day for 4 months a year | 10 hours a day for 4 months a year |
| Energy per year | 411 kWh | 611 kWh |
| Cost per hour | 7.6¢ | 8.9¢ |
| Cost per day | 61¢ | 90¢ |
| Cost per month | $18.49 | $27.49 |
| Cost per year | $74 | $110 |
| Per year in Hawaii (43.51¢) | $179 | $266 |
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What drives the difference
- Window air conditioner: Watts are for typical CEER 10-12 units. Inverter models such as the Midea U-shaped run at reduced speed most of the time and use 25-35% less.
- Mini split air conditioner: Inverter mini splits slow the compressor instead of cycling it off, so watts are average draw at rated capacity for a 20+ SEER single zone.
Ways to cut either cost
Variable-speed compressors use roughly 25-35% less energy than fixed-speed units.
See options on AmazonSeals gaps that leak cooled air outside.
See options on AmazonLets you raise the set point about 4°F for 15-35 W.
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Frequently asked questions
Which costs more to run, a window air conditioner or a mini split air conditioner?
At typical use and the U.S. average rate (17.99¢/kWh), a mini split air conditioner costs about $110 a year versus $74 for a window air conditioner. That's $36 more, or 1.5× as much.
How many watts do window air conditioner and mini split air conditioner use?
A window air conditioner typically draws 700 W (range 400–1,800 W). A mini split air conditioner draws 900 W (range 300–2,500 W). Watts alone don't decide cost. Hours of use, cycling and standby matter just as much.
Rates: EIA, 12 months ending 2026-07. Methodology.