How much does a whole-house fan cost to run in Idaho?
$13 a month while in use, May to September
- A day of use
- $0.43
- An hour of running
- $0.07
- A year (season only)
- $65.30
495 W, 6 hours a day in the evening, May to September, at Idaho’s average rate of 14.4¢ 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 | $0.07 | $2.16 | $10.88 |
| 2 hours a day | $0.14 | $4.33 | $21.77 |
| 4 hours a day | $0.28 | $8.65 | $43.53 |
| 6 hours a day typical | $0.43 | $12.98 | $65.30 |
| 8 hours a day | $0.57 | $17.31 | $87.06 |
| 24 hours a day | $1.71 | $51.93 | $261.19 |
Models range from 240 W to 750 W (Virginia Cooperative Extension). We use 495 W, the middle of that range.
Idaho compared with other states
Idaho’s residential rate is the 10th cheapest of 51 states and DC, 4.0¢ below the US average of 18.3¢ (−22%). Idaho’s rate is up 2.3¢ from June 2025 (12.1¢, +19.1%).
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 $2.16 a month in season.
Questions
How much does it cost to run a whole-house fan per hour?
About $0.07 an hour in Idaho. A whole-house fan at 495 W uses 0.495 kWh per hour, and at Idaho’s average of 14.4¢ per kWh that comes to $0.07.
How much does a whole-house fan add to your electric bill?
Used 6 hours a day in the evening, May to September, about $12.98 a month while it is in use in Idaho, or $65.30 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 $1.71 a day, or $51.93 over an average month in Idaho.
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 Idaho than elsewhere?
Idaho’s residential rate is the 10th cheapest of 51 states and DC, 4.0¢ below the US average of 18.3¢ (−22%). Idaho’s rate is up 2.3¢ from June 2025 (12.1¢, +19.1%). 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.