Revit Duct-Down when Demo'd

[mhand52]

I recently received a support call from one of my staff who were having issues properly displaying a Duct-Down symbol once it has been Demolished. Any time in previous experience, Duct-up/down display issues are being caused a view range issue which I totally understand how they work. However, after investigation and testing, I believe we have a Revit bug that I am looking to address.

I have 2 separate examples in my images attached. Both examples are representing the exact same condition of duct routing: Duct riser from -5-0" BFF to 6'-0" AFF, then another rise up to 15' AFF. This should display a duct-down to the duct at -5' BFF, and then a Duct-Up to my riser going up to 15' AFF, as it does when the duct is Existing to Remain or in New Construction.

However, after doing some testing to replicate the condition, I noticed that In Revit 2019 and beyond, duct-downs change to be displayed as a Duct-Up when the item gets demolished. My examples show 1 condition of the duct being Existing to Remain, then the Demo'd example just below it. Notice that in Revit 2019, my Duct-down gets changed to a duct-up when it is demolished, whereas Revit 2018 will display the up/down condition correctly.

I also tested this with the "Out-of-the-box" Revit MEP Templates for both 2018 and 2019 with consistent results.

[Anonymous]

This is a common problem with piping rise/drops as well.

The issue is that Revit un-assigns system parameters (which is driving the symbol) for the duct when the demolishing is selected. This is really frustrating when the project requirements are changed and a system that was demo'd must now be shown as existing. 

The only workaround our firm has discovered is a combination of demo workset and filters for the view templates to show MEP systems correctly. The issue now is when other disciplines reference the ductwork model they will not be able to control the demolition visibility without extensive view template link revision.

This would be a last resort if the visibility is your main concern as you need to weigh what is my important - correct visibility or client coordination. 

Here is an idea to vote for