Box fan vs. window fan: running cost
A window fan is cheaper to run: about $13 a year versus $16 for a box fan at typical use and 17.99¢/kWh, a $3 difference.
| Box fan | Window fan | |
|---|---|---|
| Typical watts | 75 W | 60 W |
| Watt range | 40–110 W | 30–110 W |
| Typical use | 8 hours a day for 5 months a year | 8 hours a day for 5 months a year |
| Energy per year | 91 kWh | 73 kWh |
| Cost per hour | 1.3¢ | 1.1¢ |
| Cost per day | 11¢ | 8.6¢ |
| Cost per month | $3.29 | $2.63 |
| Cost per year | $16 | $13 |
| Per year in Hawaii (43.51¢) | $40 | $32 |
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What drives the difference
- Box fan: A standard 20-inch box fan draws about 45-75 W. Running one 8 hours a day all summer costs a few dollars.
- Window fan: Twin and reversible window fans draw about 35-70 W and are most useful for pulling cool night air through the house.
Ways to cut either cost
Whole house fan
Flushes heat from the entire house in minutes and can replace hours of AC.
See options on Amazon DC-motor floor fan
Moves similar air on 10-30 W.
See options on AmazonWe may earn a commission from qualifying purchases. It never changes the numbers we show. Disclosure.
Frequently asked questions
Which costs more to run, a box fan or a window fan?
At typical use and the U.S. average rate (17.99¢/kWh), a box fan costs about $16 a year versus $13 for a window fan. That's $3 more, or 1.3× as much.
How many watts do box fan and window fan use?
A box fan typically draws 75 W (range 40–110 W). A window fan draws 60 W (range 30–110 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.