Window fan vs. whole house fan: running cost
A window fan is cheaper to run: about $13 a year versus $41 for a whole house fan at typical use and 17.99¢/kWh, a $28 difference.
| Window fan | Whole house fan | |
|---|---|---|
| Typical watts | 60 W | 300 W |
| Watt range | 30–110 W | 100–700 W |
| Typical use | 8 hours a day for 5 months a year | 5 hours a day for 5 months a year |
| Energy per year | 73 kWh | 228 kWh |
| Cost per hour | 1.1¢ | 5.4¢ |
| Cost per day | 8.6¢ | 27¢ |
| Cost per month | $2.63 | $8.21 |
| Cost per year | $13 | $41 |
| Per year in Hawaii (43.51¢) | $32 | $99 |
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What drives the difference
- Window fan: Twin and reversible window fans draw about 35-70 W and are most useful for pulling cool night air through the house.
- Whole house fan: Modern whole house fans like QuietCool draw about 100-400 W; older belt-drive units use 500-700 W. Running one in the evening can replace several hours of central AC at 3,500 W.
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 Insulated whole house fan cover
Stops winter heat loss through the fan opening.
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 window fan or a whole house fan?
At typical use and the U.S. average rate (17.99¢/kWh), a whole house fan costs about $41 a year versus $13 for a window fan. That's $28 more, or 3.1× as much.
How many watts do window fan and whole house fan use?
A window fan typically draws 60 W (range 30–110 W). A whole house fan draws 300 W (range 100–700 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.