How much does a whole-house fan cost to run in Hawaii?
$48 a month while in use, May to September
- A day of use
- $1.57
- An hour of running
- $0.26
- A year (season only)
- $239.56
495 W, 6 hours a day in the evening, May to September, at Hawaii’s average rate of 52.7¢ per kWh (EIA, June 2026). How we calculate this
Change the watts, hours or rate
What it costs at other usage levels
| Use | A day | A month in use | A year |
|---|---|---|---|
| 1 hour a day | $0.26 | $7.94 | $39.93 |
| 2 hours a day | $0.52 | $15.88 | $79.85 |
| 4 hours a day | $1.04 | $31.75 | $159.71 |
| 6 hours a day typical | $1.57 | $47.63 | $239.56 |
| 8 hours a day | $2.09 | $63.50 | $319.42 |
| 24 hours a day | $6.26 | $190.50 | $958.26 |
Models range from 240 W to 750 W (Virginia Cooperative Extension). We use 495 W, the middle of that range.
Hawaii compared with other states
Hawaii’s residential rate is the 1st most expensive of 51 states and DC, 34.4¢ above the US average of 18.3¢ (+187%). Hawaii’s rate is up 11.8¢ from June 2025 (41.0¢, +28.7%).
Ways to spend less
- Run it only when the outdoor air is cooler than indoors, usually evening and early morning.
- Open windows before switching it on so it pulls in outside air instead of straining.
- Run it one hour less a day. Saves about $7.94 a month in season.
Questions
How much does it cost to run a whole-house fan per hour?
About $0.26 an hour in Hawaii. A whole-house fan at 495 W uses 0.495 kWh per hour, and at Hawaii’s average of 52.7¢ per kWh that comes to $0.26.
How much does a whole-house fan add to your electric bill?
Used 6 hours a day in the evening, May to September, about $47.63 a month while it is in use in Hawaii, or $239.56 a year across the May to September season.
How much does it cost to run a whole-house fan 24 hours a day?
Running nonstop, a whole-house fan would use 11.9 kWh a day and cost $6.26 a day, or $190.50 over an average month in Hawaii.
How many watts does a whole-house fan use?
Models range from 240 W to 750 W (Virginia Cooperative Extension). We use 495 W, the middle of that range. Check the label on yours: cost scales directly with watts, so a 20% lower wattage means a 20% lower bill.
Why does a whole-house fan cost more or less to run in Hawaii than elsewhere?
Hawaii’s residential rate is the 1st most expensive of 51 states and DC, 34.4¢ above the US average of 18.3¢ (+187%). Hawaii’s rate is up 11.8¢ from June 2025 (41.0¢, +28.7%). The appliance uses the same energy everywhere; only the price per kWh changes.
Sources
- Virginia Cooperative Extension: Estimating appliance and home electronic energy use (reproduces U.S. Department of Energy sample wattages)
- Penn State EGEE 102: Typical range of power consumption (wattage)
- U.S. Energy Information Administration, Electric Power Monthly, Table 5.6.A: average price of electricity to ultimate customers, residential, June 2026 Figures transcribed from republications of this table on September 26, 2026; pending direct verification from the EIA API.
- Carrier page: June 2026 residential average price, citing EIA Electric Power Monthly Table 5.6.A
Usage assumptions (hours a day, season) are ours and listed on the methodology page. Found an error? Tell us.