Radon fan vs. bathroom exhaust fan: running cost
A bathroom exhaust fan is cheaper to run: about $1 a year versus $110 for a radon fan at typical use and 17.99¢/kWh, a $109 difference.
| Radon fan | Bathroom exhaust fan | |
|---|---|---|
| Typical watts | 70 W | 15 W |
| Watt range | 20–150 W | 5–120 W |
| Typical use | 24 hours a day | 1 hour a day |
| Energy per year | 614 kWh | 5 kWh |
| Cost per hour | 1.3¢ | 0.3¢ |
| Cost per day | 30¢ | 0.3¢ |
| Cost per month | $9.20 | $0.08 |
| Cost per year | $110 | $1 |
| Per year in Hawaii (43.51¢) | $267 | $2 |
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What drives the difference
- Radon fan: Radon mitigation fans run 24/7 and typically draw 20-150 W, or roughly 175-1,300 kWh a year.
- Bathroom exhaust fan: Modern bathroom fans draw 5-25 W; older units use 40-60 W. The bigger cost is removing heated or cooled air when left running for hours.
Ways to cut either cost
Prevents the fan exhausting heated or cooled air for hours.
See options on AmazonRuns only until moisture is cleared.
See options on AmazonConfirms whether a lower-wattage fan still keeps radon below 4 pCi/L.
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Frequently asked questions
Which costs more to run, a radon fan or a bathroom exhaust fan?
At typical use and the U.S. average rate (17.99¢/kWh), a radon fan costs about $110 a year versus $1 for a bathroom exhaust fan. That's $109 more, or 112.0× as much.
How many watts do radon fan and bathroom exhaust fan use?
A radon fan typically draws 70 W (range 20–150 W). A bathroom exhaust fan draws 15 W (range 5–120 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.