Evaporative cooler vs. portable air conditioner: running cost
An evaporative cooler is cheaper to run: about $33 a year versus $135 for a portable air conditioner at typical use and 17.99¢/kWh, a $102 difference.
| Evaporative cooler | Portable air conditioner | |
|---|---|---|
| Typical watts | 150 W | 1,100 W |
| Watt range | 60–1,200 W | 700–1,500 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 | 752 kWh |
| Cost per hour | 2.7¢ | 14¢ |
| Cost per day | 22¢ | $1.11 |
| Cost per month | $6.57 | $33.82 |
| Cost per year | $33 | $135 |
| Per year in Hawaii (43.51¢) | $79 | $327 |
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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%.
- 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
Better choice in humid climates where evaporative cooling does not work.
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, an evaporative cooler 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 $33 for an evaporative cooler. That's $102 more, or 4.1× as much.
How many watts do evaporative cooler and portable air conditioner use?
An evaporative cooler typically draws 150 W (range 60–1,200 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.