Duct Sizing

[dworakma]

We're still not using the duct sizing feature in Revit and I would love to start.

Curious who is using it? 

The problem I've repeatedly ran into is that airflows are not transferred back into my duct main from the terminal device.  I can assign airflow to a terminal device, such as a supply air diffuser (using a "preset" flow configuration parameter).  And that airflow will be visible at the branch duct connected to the diffuser, but once connected to a main my airflow at the main shows 0 CFM.  I believe my system is well defined starting with equipment and terminal devices, as the equipment shows the correct total airflow for the system in my system browser.  Any thoughts as to what I'm doing wrong? 

Thanks in advance.

Matt

[dworakma]

We're still not using the duct sizing feature in Revit and I would love to start.

Curious who is using it? 

The problem I've repeatedly ran into is that airflows are not transferred back into my duct main from the terminal device.  I can assign airflow to a terminal device, such as a supply air diffuser (using a "preset" flow configuration parameter).  And that airflow will be visible at the branch duct connected to the diffuser, but once connected to a main my airflow at the main shows 0 CFM.  I believe my system is well defined starting with equipment and terminal devices, as the equipment shows the correct total airflow for the system in my system browser.  Any thoughts as to what I'm doing wrong? 

Thanks in advance.

Matt

[Jrobker]

See this diagram,

[dworakma]

J,

Thanks for posting the graphic, it's very helpful.  I'll double check some of my settings when I get to the office in the morning.

Could I assume your using the duct sizing feature?

Thanks again.

[Jrobker]

No. We are not. There is no static pressure drop or CFM loss after a duct tap. Doesn't quite work. Plus issues with critical path. Doesn't work right and never has. Hopefully release 5 (2013) will get it right, since marketing claims it does.

[dworakma]

Dang that's a bummer, you got my hopes up with that fancy drawing.  Thanks for your input.

I'll keep my fingers crossed that it shows up in a next release and actually works!