Share Email Facebook Twitter LinkedIn DuctPressureDropData.Friction Property The friction of the duct. Units: (kg/(ft²·s²)). Namespace: Autodesk.Revit.DB.MechanicalAssembly: RevitAPI (in RevitAPI.dll) Version: 25.3.0.0 (25.3.0.0) Syntax C# public double Friction { get; set; }Property ValueDouble See AlsoReferenceDuctPressureDropData ClassAutodesk.Revit.DB.Mechanical Namespace