Use the Modify Duct panel to add insulation and lining to a segment of duct, or to the entire run.
This video demonstrates the following:
You can add insulation and lining to an entire duct run or to individual duct segments. Begin by selecting a main duct run. Be sure to filter out anything that is not a duct segment, fitting, or flex duct.
On the Modify Duct panel, click Add Insulation. Select the insulation type, and enter the desired thickness. When you select insulated ductwork, the insulation displays as a solid line, and the Edit and Remove commands are active on the ribbon. To change the thickness, click Edit Insulation. On the Properties palette, enter a new insulation thickness, and click Apply.
To add lining to duct segments or to an entire run, follow the same procedure to select the duct, and filter out anything that is not a duct segment, fitting, or flex duct. On the Modify Duct panel, click Add Lining. Select the lining type, and enter the desired thickness. Notice that lining displays as a dashed line. To edit or remove lining, follow the same procedure as for insulation.
When you modify duct elements, insulation and lining are modified as well. In this example, since the size of the duct has been modified, the insulation and lining are also modified. Duct insulation is included when you run an interference check against other MEP, structural, or architectural objects.