The PermissibleDuctThicknessPerSpec sheet in the HVAC.xls workbook defines the allowed thickness of various duct materials that you want in the Catalog.
This data must also be defined in the PermissibleDuctThickness sheet in the HVAC.xls workbook.
SpecName
Specify the name of the HVAC specification.
MaterialType
Type the name of the material, such as steel - carbon.
MaterialGrade
Type a grade for the material.
PermissibleDuctThickness
Type a thickness value for the material in mm (millimeters) or in (inches).