To insert an eccentric transition or an eccentric reducer using Design Master HVAC, you need to change the horizontal offset on your ductwork to “Flat on Right” or “Flat on Left.”
To do this, go to “DM HVAC->Duct Centerlines->Query Duct” and change the setting there. You can also set this when initially inserting the duct or by using the “Edit Multiple Ducts” command.
When you change this, the duct centerline will define the edge of the duct instead.
If you change the offset in the middle of the run, the ductwork will not line up. It is easiest if a whole straight run of ductwork is set to the same offset. You can change your offset when you branch at a tee or when you turn at an elbow.