Flex Duct Does Not Inherit Duct System Type

[jzimmerman3]

I am continually encountering a situation where the flex duct does not inherit the system type of the duct to which it is connected.

For example: 

1) I place a diffuser. Its classification is "Exhaust Air", its system type is "Undefined"

2) I place a duct. Its classification is "Exhaust Air", its system type is "Relief Air"

3) I draw a flex from the relief duct to the diffuser.

4) The flex duct decides to become the system type "Exhaust Air" (nothing I have drawn thus far has this system type)

5) The diffuser inherits this incorrect system type "Exhaust Air" from the flex.

So basically when drawing flex duct, Revit just picks a system type out of thin air, assigns it, and then assigns it to the diffuser as well. Revit completely ignores the fact that I already had the system type "Relief Air".

Now if I click on the flex, I can chose "Relief Air" from the system type dropdown and fix the flex and thereby the diffuser. But this is clearly not how this should be working.

Why doesn't Revit just use the duct system type in the first place? Is there a setting somewhere to remedy this, or is Revit just ignoring system types when using the flex command? Has anyone gotten around this?

[iainsavage]

If you start the flex duct command it will default to the last system type used for flex duct. You can change it in the properties pallette before placing it and that will then become the default for future flexes.

Alternatively if you right click on the end of a rigid duct, or on the connector of an air terminal, and select Draw Flex Duct on the shortcut menu it will inherit the system type from the connector.

[npsconsultingllc]

Yes - This is one of those stupidly obvious things that should have been incorporated into Revit 15 years ago. 

I feel you're pain... 

Revit loves to make you click around and use drop boxes.