Window air conditioner vs. portable air conditioner: running cost
A window air conditioner is cheaper to run: about $74 a year versus $135 for a portable air conditioner at typical use and 17.99¢/kWh, a $61 difference.
| Window air conditioner | Portable air conditioner | |
|---|---|---|
| Typical watts | 700 W | 1,100 W |
| Watt range | 400–1,800 W | 700–1,500 W |
| Typical use | 8 hours a day for 4 months a year | 8 hours a day for 4 months a year |
| Energy per year | 411 kWh | 752 kWh |
| Cost per hour | 7.6¢ | 14¢ |
| Cost per day | 61¢ | $1.11 |
| Cost per month | $18.49 | $33.82 |
| Cost per year | $74 | $135 |
| Per year in Hawaii (43.51¢) | $179 | $327 |
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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.
- Portable air conditioner: Portable ACs sit inside the room and single-hose models pull in hot outside air through leaks, so they use 30-50% more electricity per unit of cooling than window units.
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 AmazonProvides the same cooling for roughly 30-50% less electricity.
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Frequently asked questions
Which costs more to run, a window air conditioner or a portable air conditioner?
At typical use and the U.S. average rate (17.99¢/kWh), a portable air conditioner costs about $135 a year versus $74 for a window air conditioner. That's $61 more, or 1.8× as much.
How many watts do window air conditioner and portable air conditioner use?
A window air conditioner typically draws 700 W (range 400–1,800 W). A portable air conditioner draws 1,100 W (range 700–1,500 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.