Air Terminal Connection With 2 or More Flex

[Anonymous]

Hi everyone, I am new at revit and trying to connect diffuser with multiple flex ducts ( you can see from image) as you can see when I use single flex there is no problem but when I use 2 or more flex revit gives warning. I added my sample thanks everyone. 

[iainsavage]

I downloaded your file and played about with changing various connector settings, having separate parameters for each connector etc, (I also capped off the open end on the duct run) but all without success I’m afraid.

Revit seems to think the flow is passing through the air terminal and back out to the duct system.

Someone smarter than me probably knows how to model this properly.

This post is similar issue which seems? to have been solved:

https://forums.autodesk.com/t5/revit-mep-forum/how-to-set-air-terminal-with-2-connection/td-p/679230...

This seems to indicate the contrary:

https://forums.autodesk.com/t5/revit-mep-forum/having-multiple-connectors-to-an-air-terminal-unable-...

The suggestion of splitting the terminal into two smaller terminals as a workaround is what I was going to suggest initially. 

[Secttor]

Hi @Anonymous 

As the warning says set the .rfa duct connectors to global in order to have the flow working. Preset & Calculated rule is also mandatory in order to have things working smooth.

[iainsavage]

You can try this @Anonymous  but I already did and it didn’t work.

[Anonymous]

Thanks @iainsavage @Secttor i think there isn't any real solution @iainsavage i am going to do like you said multiple diffuser with 1 connection

[Anonymous]

Thanks @iainsavage @Secttor i am going to separate my air terminals like you said👍🏼

[RobDraw]

I see a couple problems with splitting the diffuser into two.

1. That is not the way it will be built. There will only be one diffuser.

2. How are you going to tag the diffuser(s)?

The way I would handle it:

If it is actually a diffuser that comes from the manufacturer with more than one connector, find out if they manufacturer has families.

If it is something that will be custom made or fabricated in the field, it will probably be a manufactured one connector family for the diffuser with a plenum of some sort attached to it with the ducts attached to the plenum. I helped develop a fully parametric plenum family for just this sort of thing a few years ago. 

[iainsavage]

I had another look at this keeping the one grille with two spigots and I was able to get the flows in the ducts to report correctly, duct sizing worked fine, airflow at the air handler was correct - but the warning remained.

[RobDraw]

I hadn't looked at the images until just now and didn't realize what the example was. Those linear diffusers will more than likely be two rather than a single diffuser. I would like verification from the OP as to what is being specified (make and model if possible) before commenting any further but what he is asking for is entirely possible with the use of a plenum.

[iainsavage]

I had another try at this.

I have a generic supply diffuser family which I made up with two connections.

Connected it up, placed Revit supplied fan family, used duct sizing tool.

It all seems to work.

Model attached.

Maybe this will help others to figure out why the OP's model doesn't work?

PS: @Anonymous , if its possible you should maybe untick the "solved" status until someone has got to the bottom of this issue?