What type of duct is best for venting range hoods?
Range hoods must be vented using metal duct. If there’s a choice between flexible metal and smooth metal, we recommend the smooth, since the many ridges in flexible metal duct can create turbulence and diminish airflow. Of course, NEVER use 4″ dryer duct or any plastic duct on a range hood installation. Additionally, the minimum size duct allowed on most range hoods is 3 ¼” x 10″, equivalent to a 6″ circumference. More powerful hoods require even larger duct sizes, up to a 10″ circumference. When remodeling and changing hood and cooking equipment types, do not reduce the ductwork size to less than the size specified for the range hood, since doing so restricts the performance of the range hood ventilator.
