Attic fan vs. whole house fan: running cost
A whole house fan is cheaper to run: about $41 a year versus $46 for an attic fan at typical use and 17.99¢/kWh, a $5 difference.
| Attic fan | Whole house fan | |
|---|---|---|
| Typical watts | 300 W | 300 W |
| Watt range | 100–500 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 | 256 kWh | 228 kWh |
| Cost per hour | 3.8¢ | 5.4¢ |
| Cost per day | 30¢ | 27¢ |
| Cost per month | $9.20 | $8.21 |
| Cost per year | $46 | $41 |
| Per year in Hawaii (43.51¢) | $111 | $99 |
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What drives the difference
- Attic fan: Powered attic ventilators draw about 200-400 W. They can pull conditioned air out of the house through ceiling leaks, sometimes increasing AC use.
- 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
Insulated whole house fan cover
Stops winter heat loss through the fan opening.
See options on Amazon Solar attic fan
Runs on its own solar panel with no grid electricity.
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, an attic fan or a whole house fan?
At typical use and the U.S. average rate (17.99¢/kWh), an attic fan costs about $46 a year versus $41 for a whole house fan. That's $5 more.
How many watts do attic fan and whole house fan use?
An attic fan typically draws 300 W (range 100–500 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.