What dryer booster fan means
A dryer booster fan is an inline fan installed in a long dryer vent that switches on when the dryer runs to push exhaust the full distance.
Where it matters on a duct and dryer vent cleaning job
When a vent run is longer than the dryer maker allows, a listed booster fan is often the fix. Quote it with the electrical work it needs and label the run so the next tech knows it is there.
What the model code says
- Where the equivalent length of a dryer duct exceeds 35 feet, the length must be on a permanent label within 6 feet of the duct connection. (IRC 2021, Chapter 15)
Check which code edition your building department enforces for dryer booster fan before you quote.
What it costs
Jobs that involve dryer booster fan are priced in the dryer vent cleaning cost guide: about $150 typical, usually $100 to $190. The guide shows its sources and what moves the price. The dryer vent cleaning cost calculator prices a job line by line.
Work it out
- Free calculator: Dryer vent cleaning cost calculator
- Cost guide: Dryer vent cleaning cost
- Tools, templates and guides: Free duct and dryer vent cleaning resources
Sources: 2021 International Residential Code, Chapter 15, Exhaust Systems (ICC). Checked October 9, 2026.