Flexible duct should not sag more than what measurement per linear foot?

Flexible duct should not sag more than 1/2 inch per linear foot to ensure optimal airflow and system efficiency. When flexible ducting sags, it creates low spots that can trap air and debris, leading to reduced airflow and possible system performance issues. Excessive sagging can also lead to kinks or pinches in the duct, further obstructing airflow and increasing the likelihood of damage to the duct material. Keeping sagging under 1/2 inch helps maintain the integrity of the duct system, promotes effective air distribution, and prevents long-term maintenance issues. This measurement is aligned with industry standards to ensure that the ductwork operates effectively within the HVAC system.