Graphics Programs Reference
In-Depth Information
Conversion
This section is for setting the standard Duct Type and
Offset parameters for both main and branch runs, as well as the flex
duct type and maximum flex length allowed. These are the settings that
will be applied when the Generate Layout feature of Revit MEP is used.
Rectangular, Oval, and Round
In each of these you can specify the
standard sizes for your ductwork, whether these sizes should appear in
size lists, and whether they should be used by Revit when it is
automatically sizing the ductwork.
Calculation
Here you can see the calculation Revit uses for its duct
sizing, velocity, and pressure drop calculation. New to Revit 2015, you
can now select between the original calculations (The Darcy-Weisbach
equation used in the ASHREA handbook of fundamentals) and the
Haaland equation (based on guidelines from the Chartered Institution
of Building Services Engineers [CIBSE]).
Now we can look at the duct type properties. You can access this from the
families section of the Project Browser. Select Duct and choose any duct
type, right-click, and choose Type Properties. You can create new duct types
by duplicating existing ones.
In this dialog box, apart from parameters listed under the Identity Data
group, there is only the Roughness value to be changed; however, from here
you can also access the Routing Preferences dialog box (see
Figure 9.6
).
With Routing Preferences, you can apply a list of each fitting you wish to
be used and leave out those you do not. For example, you may wish to use
flanged fittings only. You can also set the preferred junction type (Tap or
Tee), although it is always a good idea to include at least one tap and one
teeconnectioninthejunctionlistbecauseoftenyouwillneedboth.Defining
the routing preferences correctly is essential to enable efficient modeling of
duct systems. For standard duct types used regularly within the office, the
routing preferences should be set up in the template file. See Chapter 2 for
more information.
