What is the recommended distance between supports for flexible duct installed horizontally?

The recommended distance between supports for flexible duct installed horizontally is typically 5 feet. This distance is important to ensure that the flexible duct maintains its shape and does not sag, which can lead to airflow issues and increased resistance. Proper support prevents excessive bending and stress on the duct material, thereby preserving its efficiency and longevity in a heating, ventilation, and air conditioning (HVAC) system.

When flexible ducts are too far apart in their supporting points, they may droop under their own weight or when subjected to air pressure, reducing the effectiveness of the air distribution and potentially leading to problems such as noise and air leaks. Therefore, a 5-foot support spacing strikes a balance between stability and flexibility, making it the standard recommendation in the industry.