For the experienced design drafter, using the automatic tools may seem too limiting. However, wih experience and use, most users eventually settle for a variety, sometimes for no better reason than “a change is as good as a rest.” Sometimes, however, the manual tool is much more efficient, especially when connecting different areas into a system or laying out runs back to a
rooftop AHU.
To begin manual duct routing, do the following:
1. Click the Duct tool on the Home tab on the ribbon, and then choose the type and its various options from the Properties palette, as shown in Figure 10.23.
Figure 10.22
Completed duct
layout
Figure 10.23
Duct types
Note the default settings in the Properties palette for constraints, including Justification, Reference Level, and Offset. The System type is undefined and, because the duct is unconnected, the airflow is 0.
You can adjust additional properties from the Options Bar and the Modify/Place Duct tab.
Additional functionality in Revit MEP 2012 allows you to inherit the elevation and size of existing ducts when connecting to them. For round or oval ducts, you can also choose the Ignore Slope To Connect option, meaning that the duct will connect regardless of slope, or use the specified angle.
2. The duct can then be created/drawn to whatever path you choose. For vertical offsets, type the new height into the offset box on the Options Bar. For an angled setup or setdown, it is best to work in an elevation or sectional view.
In Figure 10.24, the duct has been split and a section created. To create a duct set-down, you would hover over one end of the duct, right-click the connector, and select Draw Duct. The duct would then be drawn along the preferred route.
3. Using tools such as the Trim command, you can complete the run as shown in
Figure 10.25.
Figure 10.24
Editing duct in
sections
When creating ducts that set down/up or drop/rise, it is much easier to model these in a section or elevation view, as seen in Figures 10.24 and 10.25. To do this, first you need to create a suitable view. Quite often, individuals have a personal sectionthat they move around the model.
It can be opened when required, and then the duct? (or whatever service is being worked on) is modified and the view is closed
