utility · 300W typical
Running a attic exhaust fan (passive-intake) costs about $4.46/month.
That's the typical attic exhaust fan (passive-intake) at 300W, run 6 hours a day at the US-average rate of 16.5¢/kWh. Change any of those and the number moves — use the calculator below to see yours.
Estimated cost
A attic exhaust fan (passive-intake) draws full power only while the thermostat/compressor is running — about 3.0 effective hours at 300W across your 6-hour window.
How you use it
Cost shifts with how long it's on.
The same attic exhaust fan (passive-intake) can cost very different amounts depending on usage patterns. Three common scenarios, at the US-average rate.
summer heat dump
$4.46
per month
thermostat-triggered
year-round moisture
$1.49
per month
humidistat-triggered
Where you live
$8.07 spread between the cheapest and priciest states.
Same appliance, same hours of use, different zip code — the monthly cost varies this much.
| State | Rate | Monthly | Yearly |
|---|---|---|---|
| Hawaii | 41.2¢ | $11.12 | $135.34 |
| California | 31.4¢ | $8.48 | $103.15 |
| Massachusetts | 30.8¢ | $8.32 | $101.18 |
| Connecticut | 28.7¢ | $7.75 | $94.28 |
| Rhode Island | 27.9¢ | $7.53 | $91.65 |
| New Hampshire | 24.6¢ | $6.64 | $80.81 |
| Alaska | 24.3¢ | $6.56 | $79.83 |
| New York | 22.3¢ | $6.02 | $73.26 |
| Maine | 22.1¢ | $5.97 | $72.60 |
| Vermont | 21.5¢ | $5.81 | $70.63 |
| Michigan | 19.3¢ | $5.21 | $63.40 |
| New Jersey | 19.1¢ | $5.16 | $62.74 |
| Maryland | 18.4¢ | $4.97 | $60.44 |
| Pennsylvania | 18.1¢ | $4.89 | $59.46 |
| District of Columbia | 17.8¢ | $4.81 | $58.47 |
| Wisconsin | 17.4¢ | $4.70 | $57.16 |
| Delaware | 17.2¢ | $4.64 | $56.50 |
| Illinois | 16.9¢ | $4.56 | $55.52 |
| Ohio | 16.6¢ | $4.48 | $54.53 |
| Nevada | 16.3¢ | $4.40 | $53.55 |
| Indiana | 15.8¢ | $4.27 | $51.90 |
| Virginia | 15.7¢ | $4.24 | $51.57 |
| Minnesota | 15.6¢ | $4.21 | $51.25 |
| Colorado | 15.4¢ | $4.16 | $50.59 |
| Alabama | 15.2¢ | $4.10 | $49.93 |
| West Virginia | 15.2¢ | $4.10 | $49.93 |
| Florida | 15.1¢ | $4.08 | $49.60 |
| New Mexico | 14.8¢ | $4.00 | $48.62 |
| Texas | 14.8¢ | $4.00 | $48.62 |
| Arizona | 14.7¢ | $3.97 | $48.29 |
| South Carolina | 14.7¢ | $3.97 | $48.29 |
| Kansas | 14.6¢ | $3.94 | $47.96 |
| Georgia | 14.2¢ | $3.83 | $46.65 |
| Iowa | 14.1¢ | $3.81 | $46.32 |
| North Carolina | 13.9¢ | $3.75 | $45.66 |
| Missouri | 13.6¢ | $3.67 | $44.68 |
| Oregon | 13.4¢ | $3.62 | $44.02 |
| Tennessee | 13.3¢ | $3.59 | $43.69 |
| Kentucky | 13.2¢ | $3.56 | $43.36 |
| Mississippi | 13.1¢ | $3.54 | $43.03 |
| Oklahoma | 13.1¢ | $3.54 | $43.03 |
| South Dakota | 12.7¢ | $3.43 | $41.72 |
| Montana | 12.4¢ | $3.35 | $40.73 |
| Nebraska | 12.2¢ | $3.29 | $40.08 |
| Arkansas | 12.1¢ | $3.27 | $39.75 |
| Washington | 12.1¢ | $3.27 | $39.75 |
| Louisiana | 11.9¢ | $3.21 | $39.09 |
| Wyoming | 11.6¢ | $3.13 | $38.11 |
| North Dakota | 11.5¢ | $3.11 | $37.78 |
| Utah | 11.4¢ | $3.08 | $37.45 |
| Idaho | 11.3¢ | $3.05 | $37.12 |
Efficient vs. inefficient
A $63.24/year difference across the wattage range.
Swapping a high-draw model for an efficient one pays for itself. Here's what that looks like annually at typical usage.
Most efficient
150W
$2.23 per month
$27.10 per year
Typical
300W
$4.46 per month
$54.20 per year
High draw
500W
$7.43 per month
$90.34 per year
When it hits hardest
summer peak
June-September peak.
Ways to cut the cost
- 1
Install thermostat set to 100°F+ threshold
Prevents 60-70% of unnecessary runtime
- 2
Seal attic floor leaks first — otherwise fan pulls conditioned air up
Wasted AC cost can exceed fan savings
- 3
Consider solar-powered — free to run
Eliminates 300-500 kWh/year
Real-world wattages
Pulled from actual spec sheets.
| Brand | Model | Watts |
|---|---|---|
| QuietCool | AFG ES-1500 | 180W |
| Broan | 355BK | 340W |
| Air Vent | 53316 Gable Fan | 340W |
Picks that actually move the needle
Three products worth comparing if you're thinking about upgrading or supplementing what you have.
Some links below are affiliate links. If you buy, we may earn a small commission — it never changes the price you pay, and we only recommend picks we would stand behind.
See also
Related appliances
Sources: www.energy.gov · www.energystar.gov
Last updated: 2026-04-13