The instructions state rigid round 4" venting tube. Broan also makes 4' round flexible vent tubing, is the flexible tubing an acceptable substitute?
Thank you for your question on the Broan QT90E ventilation fan. It is recommended, where possible, to use rigid duct. It has less resistance to air flow and allows the fan to operate much more efficiently. If flexible duct is used, be sure the duct is as straight as possible.
Date published: 2014-05-20