Residential Building Inspector B1Building Planning and Life SafetyMedium
An inspector is performing a final inspection of a newly constructed single-family dwelling. The dwelling includes a clothes dryer that exhausts through a flexible transition duct to the main exhaust duct. What is the maximum length permitted for this flexible transition duct?
- A8 feet
- B4 feet
- C10 feet
- D6 feet
Show answer & explanationAnswer & explanation
Correct answer: A. 8 feet
To prevent excessive lint accumulation and maintain efficient dryer operation, the IRC limits the length of flexible transition ducts used for clothes dryer exhaust. The maximum permitted length for this type of duct is 8 feet.
Why the other options are wrong
- B. While shorter is generally better, 4 feet is not the maximum allowed.
- C. 10 feet exceeds the maximum permitted length and could lead to performance issues and fire hazards.
- D. 6 feet is a common length for other flexible ducts but not the maximum for dryer transition ducts.
Dryer Flexible Transition Duct Length
The maximum permissible length for a flexible duct that connects a clothes dryer directly to the rigid dryer exhaust duct system, designed to minimize lint buildup and maintain exhaust efficiency.
- Connects dryer to rigid exhaust duct.
- Limited in length by code.
- Prevents lint accumulation and fire hazards.
Memory trick: Flexible '8's, no more, for dryer flows.