multiple air outlet options for one device

[HVAC-Novice]

I have the attached make-up air unit and it works fine in my duct system for pressure drop and flow calcs. the problem is, the unit has 3 options to discharge air (actually 5, but i only use 3). it can discharge on top, bottom or the end. In any given design only one of the options is used. Instead of creating 3 different families, I want to use one family, and just cap the unused duct connectors. 

but the only way my duct system works if I manually assign the intake connector to use one of the 3 flowrates (make both discharge and intake connector to be the same parameter). if i make them separate parameters, the duct system and pressure doesn't go through the unit. 

I tried to make the intake a separate parameter and use an if-function to determine he flow. it works in a way that only the used discharge connector provides the flow to the intake connector. but it doesn't work in the system.

In my case there is a louver and some ductwork to the unit. And then more ductwork from the unit to the diffusers. If I manually assign the actually used discharge connector and the intake connector the same parameter, the system inspector correctly shows the entire duct system up and downstream of this unit and system pressuredrop is 0.39 in. If i do one of my automatic ways (the if-function etc.), the system inspector only shows from louver to this unit and pressuredrop is 0.06 in only. 

How can I set the connectors in this family that I could use any of them? Or is this impossible and I'm condemned to use separate families for top, bottom, and end-discharge (the unit also has the option to discharge right and left side, I doubt I will need that)

I ran into similar issues a while back for piping and the problem is that Revit doesn't have a yes/no option for duct or pipe connections. 

[craigjonnson]

I have got around this in the past by hosting the spigot connection into the family. Setting formula's for angle rotation and offsets. Its a complicated method but can be done.

 

[HVAC-Novice]

This is a great idea! I assume you host the connector on the little extrusion. Do you host that little extrusion just on the  centerline planes and use a nested family for the extrusion? Would you be able share an example for me to reverse-engineer? 

I have a few families that would benefit from this. One tricky one is a heating radiator (like the Runtal) that have all the piping options (left, right, bottom inlet etc.). I ended up having a separate family for each option. but this also makes family maintenance hard since any change has to be done in many families. 

[craigjonnson]

No, i added an angle into a host and then the offsets into the second host. I'll send the example i used. Im on leave until Thursday. 

[HVAC-Novice]

Just checking if you are still able to share an example family? No rush, for this project I can just use my "hack" of manually removing the unused connectors. but this could be helpful on many future families/projects. 

My initial idea is to use a reference line that rotates and place the connector on one of the line's plans in a distance....  

[craigjonnson · Accepted solution]

Here's my example which I created back in 2016 for rotating spigots on an Air Terminal. Ive added the example to your family which you can test and modify to suit your requirements, but im sure you could find an easier method for you.

Note: I have modified your family to allow the width, Length to extend out equally to allow the formula to work.

There is an integra instance based parameter assigned to the spigot. the options are:

• 1. Spigot on Front
• 2. Spigot on top
• 3. Spigot on bottom.

[HVAC-Novice]

Thanks so much!

It will take me a while to fully create my own family with this method (or find a different method). but this is a good start for me. I wouldn't have been able to come up with this on my own.