By James Philip
When working in Revit MEP the transition from one duct size to another is created automatically.
However, the default transition is concentric. This is defined in the routing preferences which can be found by selecting the duct. Then choose Edit Type.
In the dialogue box that appears select routing preferences.
Another dialogue box appears which has all of the connection settings.
The default fitting for transition is Concentric Taper. Use the load family button to import the Eccentric Taper. Once loaded it can be chosen to replace the Concentric Taper. However once applied the transition still appears concentric.
To rectify this, select each duct and choose Justify on the ribbon.
The ribbon then changes to display the justify option; choose the one you require.
The ducts should now be justified correctly.