Evaporative cooler vs. window air conditioner: running cost
An evaporative cooler is cheaper to run: about $33 a year versus $74 for a window air conditioner at typical use and 17.99¢/kWh, a $41 difference.
| Evaporative cooler | Window air conditioner | |
|---|---|---|
| Typical watts | 150 W | 700 W |
| Watt range | 60–1,200 W | 400–1,800 W |
| Typical use | 8 hours a day for 5 months a year | 8 hours a day for 4 months a year |
| Energy per year | 183 kWh | 411 kWh |
| Cost per hour | 2.7¢ | 7.6¢ |
| Cost per day | 22¢ | 61¢ |
| Cost per month | $6.57 | $18.49 |
| Cost per year | $33 | $74 |
| Per year in Hawaii (43.51¢) | $79 | $179 |
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What drives the difference
- Evaporative cooler: Evaporative coolers only run a fan and small water pump, so they use 75-90% less electricity than air conditioners, but they work well only in dry climates with humidity below about 40%.
- 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.
Ways to cut either cost
Better choice in humid climates where evaporative cooling does not work.
See options on AmazonVariable-speed compressors use roughly 25-35% less energy than fixed-speed units.
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Frequently asked questions
Which costs more to run, an evaporative cooler or a window air conditioner?
At typical use and the U.S. average rate (17.99¢/kWh), a window air conditioner costs about $74 a year versus $33 for an evaporative cooler. That's $41 more, or 2.3× as much.
How many watts do evaporative cooler and window air conditioner use?
An evaporative cooler typically draws 150 W (range 60–1,200 W). A window air conditioner draws 700 W (range 400–1,800 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.