What is the recommended length for an ogee offset for 20" x 12" duct that must offset 10" on the 12" side?

The recommended length for an ogee offset in ductwork calculations ensures both effective airflow and physical space considerations when adjusting the duct's path. Specifically for a 20" x 12" duct that needs to offset 10" on the 12" side, the proper calculation for the ogee offset takes into account the dimensions of the duct and the required offset distance.

An ogee offset typically follows a certain formula where the length is derived from the vertical and horizontal changes in direction. The recommended length of 22" accommodates the change in airflow direction while maintaining adequate duct volume, which is essential for efficient HVAC operation.

This ensures that the duct remains functional and minimizes turbulence, which could occur if the offset were too short or if sharp bends were utilized instead. Sufficient length in the ogee helps maintain smooth airflow and prevents pressure drops that could impact the overall efficiency of the HVAC system. Additionally, other choices do not align with the necessary calculations for this specific duct scenario, either being too long or too short and not adhering to the standard engineering practices used in duct sizing and design.