Remove Hanger
To remove a hanger from a duct, go to
Ribbon: 
Remove Hanger
Pulldown Menu:
You will be prompted to identify which hanger is to be removed.
Select hanger on duct to remove:
Not all hangers can be removed. If the selected hanger is necessary based upon the spacing requirements set for the duct, you will not be able to remove it and the dialog box shown below will appear.
