What is the maximum approved length for a transition duct between a dryer and exhaust duct?

The maximum approved length for a transition duct between a dryer and exhaust duct is 8 feet. This requirement is established to ensure efficient airflow and minimize the risk of lint buildup, which can lead to fire hazards. Transition ducts are intended to connect the dryer to the main exhaust duct, and limiting their length helps maintain optimal performance of the dryer while reducing potential obstructions to airflow.

If the transition duct is longer than the specified length, it can negatively impact the effectiveness of the ventilation system, potentially causing the dryer to overheat and increasing the likelihood of lint accumulation. A length of 8 feet provides a balance between flexibility in installation and ensuring adequate airflow for safe and efficient operation.