Collect all ductwork downstream of VAV Boxes

Good day, I hope everyone is staying safe. I was hoping someone could help me with a method of collecting all the ductwork downstream of the VAV boxes. I know that the MEPover package has a node to collect all elements upstream of selected elements. I tried to modify the python code of the node to reverse the direction, but it is only partially successful. I can only get it to select the main run of ductwork from the VAV box, not the branches feeding all of the diffusers. If anyone can help, I would be very appreciative.

Notice this is a bit old but you could take all the duct, filter down to just supply, then filter out the items given by the MEPover node to be left with just the downstream items.

@dsmith thank you for your response but I have tried what you suggested. the problem is that the MEPover node is not collecting all of the items.

What items is it not collecting?

@dsmith it is not collecting all of the ductwork that is connected downstream of the VAV. it appears to only collect the critical path and not all of the connected branches. I modified the MEP Over Node to reverse the direction it collects the duct. It works but just doesn’t collect all connected ductwork.

You could collect all ductwork then use the MEPOver node (unedited) and remove those instances and be left with the downstream.

@dsmith Some times the solutions are simple. :grinning:

It’s easy to get on a path and get stuck on it.

Good luck with the script.

Hi @dmillerSNYXQ

It sounds like you were successful at modifying the python node so that it could collect the elements downstream of the selected component.

I’m trying to make a method that would allow me to select the main run downstream of my sewer air valve so as to mark up which part of my sewer network is vented.

I also found the upstream node, but could not find a downstream one and I’m completely green when it comes to python.

How did you reverse the python script to search upstream instead of downstream?