To Draw a Vertical Duct Run
Add duct, and begin laying out the duct run, as explained in Drawing a Duct Run.
Specify the point in the layout where you want to start the vertical segment.
In the Properties palette, specify the elevation of the endpoint of the vertical segment.
Continuing specifying points for the duct run geometry.
Related Concepts
About Duct Properties Palette (Add Mode)
About Adding Ducts
Related Tasks
To Draw a Duct Run