By Jordan Mussett, IMAGINiT Building Solutions
There are several different methods to use when creating duct systems. You can create all the duct and let the systems create themselves, which is never really a good idea. Each time you create a piece of duct that is not connected or copied from an existing piece, Revit will make you a new System Name. Example - Mechanical Supply Air 1 (referenced as MSA 1 later), Mechanical Supply Air 2, etc. If you connect them in the correct order, they will consolidate, but not always.
The next method is to create the duct system from the VAV, then add the Air Terminals. The last method we will discuss is when you create the duct system from the Air Terminal, then add the VAV and AHU to the equation, working your way back upstream. It feels backwards because it isn’t typically how systems are designed, or how the designer is logically thinking out the system.
What I am chiefly concerned about is the organization of the systems in the System Browser, and the ability of the software to provide you with the most information possible.
Here is the basic layout I will be working with. The main AHU is in the lower left, there is one VAV in the hall, and supply air terminals spread throughout the other rooms.
I will start with the first method. Not creating any systems and kind of let them create themselves.
The Systems Browser ends up looking kind of like this:
One of the main negatives is the organization obviously. The other downside is that if you wanted the supply air systems to be named or numbered differently, you would need to get into the system editor and change them.
With the second method, I created the supply air systems from the AHU to the air terminals. In the graphic, lower left to upper right.
The System Browser ends up looking a little something like this:
Here is the graphic on the last setup:
For this, I would select the air terminals, then select create duct system. I would finish off that system by clicking on the VAV as my source for that system. I would do the same process at the VAV level and select the AHU as the source.
Then the System Browser looks like this:
Notice MSA 1 falls under MSA 2, and that’s what I want. Additionally, when I create ducts to connect all these devices, they will automatically be in the correct system. Finally, the software is able to calculate the flow of all the systems for you.
It might take a little time to set your systems up properly but it will be worth it. Duct drawn from the equipment in the system have the correct System Name.