Rectangular ducts - wrong dimensions

[francesca.duffizi]

Hi, I get an issue working with rectangular ducts. I set the correct size on a plan view, it's correct in sections (cut duct) but INCORRECT when duct is not cut! Width and height are reversed and the tags are completely a mess!

When I select an object in the section view I can see the right values for Width and Heigth, and Dimension in the Properties, but at the same time I get reversed values in the option bar...and the tag (which is referencing the Dimension parameter) is wrong!

It is insane...how can a parametric software have this kind of bugs?

Has anyone a solution for this issue? I don't think having a double tag is an acceptable solution...

Below is a basic sample, tags are referencing the Dimension parameter; the correct view is the plan, showing the real situation with correct tags... every section has a bug. 

[isosa9APBT]

Is this happening only on a specific project or across the board? Can you attach a file that we can open and see if we see the same issue? Most likely is a software bug. I found this looking around, I'm not sure if this is the same as your bug, but it sounds similar.

https://knowledge.autodesk.com/support/revit/troubleshooting/caas/sfdcarticles/sfdcarticles/The-fabr... 

[francesca.duffizi]

@isosa9APBT This happens in every project, I tried also different versions of Revit (2020 and 2022) but nothing changes.

You can try opening a new project (I used the mech template), just place a duct and 2 sections.

I will upload my file as soon I come back at the PC!

[francesca.duffizi · Accepted solution]

I found out that what Autodesk considers a normal behaviour: showing the visible edge as the first dimension in duct tags.

That said I found a solution to the tag issue too. Below is a basic sample with a multi parameter tag showing different parameters in every view (it's easier to look at what changes and what does not): the solution to get the effective section of a rectanguar duct in a consistent way (stable in every view) is to manually combine LxH, as shown in the last row. At least it works, even if the option bar still show the reversed values.

I wonder why there is no official documentation about how things are supposed to work, really frustrating to find a patch for their stuff.

[isosa9APBT]

Very interesting. I never experienced that, but I'm glad you found a workaround. Hopefully, someday they get their stuff figured out. 

[RobDraw]

Is everyone a critic?

[iainsavage]

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@francesca.duffizi  schrieb:

I found out that what Autodesk considers a normal behaviour: showing the visible edge as the first dimension in duct tags.

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I was taught that as being standard practice, even when we were using pen and paper. I don’t think its Autodesk’s convention.

[HVAC-Novice]

That may be true for paper.

But what happens to me in Revit is that I start a duct in plan view and for some reason continue in section view. But to attach the rectangular duct in section view, I have to manually enter/swap width height dimensions since Revit otherwise would add a transition in order to draw the duct the wrong way (height and width flipped). 

I don't really care if the tag shows is one way or another. My complaint is more for creating ducts where I have to manually swap height and width in certain types of view.

[iainsavage]

I was only commenting on the tagging part - I was taught first dimension is the one you see in the view, so width in plan, height in section. Pretty sure that’s in at least one of the recognised standards.

As far as the Revit bit is concerned, I’ve never understood why there couldn’t just be a toggle button beside the dimensions to allow the width and height to be quickly reversed. So I share your frustration on that.

[francesca.duffizi]

It's a convention ok, but it is intended only for tagging. What happens in Revit is that you really see the option bar changing its values depending on the view you are, and if what you see in Revit (as BIM parametric sw) are the parameters of the duct element, I think it's not correct they reverse: every object has its dimensions and they do not change.

The same parameters in the same view have different values in the Properties menu and in the Option bar (at the same time!): is this parametric or what? Where is the truth? Let me say it's a little misunderstanding,even compared to the behaviour of the option bar with the other objects...don't you think?

If the Option bar reports something different, well it should be said somewhere...

At most, tags should change and not duct parameters: this is what I expected.

[RobDraw]

Obviously, this all depends on your point of view, literally and figuratively. 

[ToanDN]

Draw using Duct Placeholders on elevation (or both plan and elevation), then convert Duct Placeholders to Duct.

[fruity101079]

Welcome to revit where hvac seems to not be considered a real thing to invest in...

[RobDraw]

Thanks for your contribution but you are quite wrong.

[fruity101079]

Well, there are so many thing going wrong in this speciality... just look at all updates through years, there are almost nothing new, nothing fixed for us.

[RobDraw]

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@fruity101079 wrote:
Well, there are so many thing going wrong in this speciality... just look at all updates through years, there are almost nothing new, nothing fixed for us.

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Revit has it's shortcomings for every trade. There's no need to play the victim.

There also have been a lot of improvements and more recently they are making them based on user requests.

[anassbensefiyan]

bonjour, s'il vous plait je veux cette famille

merci 

[fruity101079]

It's not the way I think it should or it should not, in this particular case, this is clearly a bug/error.

Another subject i started before seeing this one, same problem : https://forums.autodesk.com/t5/revit-ideas/mep-height-and-width-ducts-are-inverted-in-section-views/...

[fruity101079]

"even if the option bar still show the reversed values."
So there is still a issue. You can't draw something in a section view without manually invert values in the option bar.

[RobDraw]

You can call it what you want but opinions don't have much weight in the technical world.