The duct justification tool has been given a big makeover in Revit MEP 2012. Selecting a duct or a run of ducts/fittings gives the user the option to change justification with greater ease than in previous releases. Select your duct run and from the Modify tab, select Justify.
This opens the Justification Editor, as shown in Figure 10.26. Here, the control point can be displayed, and the alignment along the selected route can be selected by using the Alignment Line button. You can choose justification by using one of the nine Justification control buttons.
This can have an effect on your layout, so it is best to use this tool in small, easy-to-view sections or 3D views.
It is worth making the point here that duct justification is not available for duct placeholders.
Another new enhancement to the 2012 version of Revit MEP is the ability to change an entire duct run from one type of duct to another. In previous versions, this involved multiple selections and filters. Now all the user has to do is to select the duct run, as you can see in Figure 10.27. Here, the duct system has been selected, and the only proviso is that flexible ducts, air terminals, and mechanical equipment are not in the selection set.
This is a logical step forward, because the ducts and duct fittings in the selection set are usually also defined within the duct type. Therefore, when the objects are selected and the Change Type button is used, you are presented with a condensed Properties box that allows you to
change the run type for others already in use in the project (see Figure 10.28).
Direction of flow and graphical warnings have also been added to the MEP toolset in 2012.
The direction of flow is a temporary display when you select any object that has a mechanical or piping connection. This should be a huge benefit for designers and drafters, as they no longer have to guess which way air (or gas or water) is flowing through an object. As you can see in Figure 10.29, the selected VAV box has two supply ducts: one entering from the right and the
other exiting left. There is also a return-air and electrical connection.
Warnings related to MEP connections have also been given a boost in this release, so you can have graphical notifications when there is a disconnect in the system. You can change the warnings to suit your current task from the Analyze tab. Select the Show Disconnects button and then select the options you require.
To extend an existing layout, as indicated in Figure 10.30, select one of the fittings (typically a bend or tee). You will notice a small plus sign (+) adjacent to the side of the fitting that does not have a connector. Clicking this will turn a bend into a tee, and a tee into a cross, eliminating the need to delete a fitting and insert an appropriate one.