Best Method of Connecting Duct Fittings and applying System Information

[mhillis]

Good Afternoon Everyone,

I've got a bit of a problem that I'm trying to optimize a solution for. I've got an add-in that will take information from a DWG file and import Families into a Revit Project file based on that information, this is primarily duct fitting objects.  Now, I'm trying to take System information (Air Type/System Name) and apply it to these fittings.  Now I realize, in a direct manner, this isn't possible.  These properties on a Duct Fitting Revit Family are Read Only. 

Now, I realize Revit really wants EVERYTHING in a duct system to be present before it assigns any of that relevant information to it, from Mech. Equip to Air Terminal and all the duct in between.  The problem is that most people who draw this stuff in AutoCAD, who desire to import it into Revit, simply do not draw everything from start to finish in one drawing.  You'll have AHUs in the penthouse connecting to duct all the way in the basement, however; again people don't draw this way a lot of times in AutoCAD, they tend to have each level of a building in its own seperate DWG.  I imagine, since too much many things in a DWG can cause AutoCAD to get incredibly slow.  So my add-in really should work with these guys being able to import a level at a time so they don't have to waste a buttload of time trying to slam everything into a DWG file, because every action at that point would take a very long time even on the best of computers.

Now, I've been able to achieve this in bits and pieces.  These methods primarily involve taking a temporary Mech. Object and connecting it to a fitting so it inherets system properties, but this isn't ideal for quite a few reasons, I have a good bit of trouble applying the same System Name to multiple objects with this method. 

I would really like the doc.Create.NewMechanicalSystem routine to work with stuff outside of Air Terminals/Mech. Objects since they are part of the system anyway, unfortunately that doesn't work.  

Do any of the more experienced Revit users have any suggestions for applying System information to a duct fitting in this situation?  

Thanks. 

[jeremytammik]

Dear Mhillis,

Thank you for your query.

Yes, I do have a suggestion for you, in spite of knowing next to nothing about the proper approach to HVAC modelling in Revit.

However, Revit MEP 2012 introduced the MEP placeholder elements for the very purpose you describe, afaik:

http://thebuildingcoder.typepad.com/blog/2011/07/mep-placeholders.html

So you might want to take a look at those.

They can be converted back and forth to real ducts as you please.

You could attach what information you have to the in extensible storage, and leave out what is still missing.

This also reminds me of my really old Pipe to Conduit Converter, for some reason, but that is probably off topic:

http://thebuildingcoder.typepad.com/blog/2010/05/pipe-to-conduit-converter.html

I hope this helps.

Best regards,

Jeremy