When run horizontally, how often must flexible duct be supported?

Flexible duct that is run horizontally must be supported at intervals to ensure it maintains its intended shape and performance, while also preventing sagging or drooping which can lead to inefficiencies. The correct answer of supporting flexible duct every 5 feet aligns with the industry standards that have been established for maintaining optimal airflow and reducing potential for damage or air leakage.

Supporting the ductwork at these intervals helps to ensure that it does not collapse under its own weight or the weight of any insulation that may be present. Additionally, proper support is essential for the longevity of the duct system, as it minimizes stress points, which could lead to wear and tear over time. This practice aids in providing a reliable air distribution system, ensuring that heating or cooling is effectively delivered throughout a space.