Static Pressure reporting to a revit family

[Paul_Rhiannon]

Hello,

I'm curious if there has ever been an attempt to push duct static (and pipe pressure losses) into a revit family, just like GPM / CFM... I realize that it's achievable using Dynamo (like all things), but when you're layout out duct and pipe, who wants to stop and run a script? What I'm envisioning is for revit families to take the data from the supply and return static pressures, push into the family, and use those inputs to manipulate the family. There is the caveat that, as with all things, the data you get out is only as good as the data you put in, so you need to have your duct static calculating correctly (like that default 4" ESP on fire dampers).

To give an example, it's a common practice to simply specify ducted fan coil units at 0.5" of static. Let's say nobody bothered to check the actual static and it turns out one of them is actually 1.0" of static. If the static pressure was automatically fed into the family, you could do a multitude of things, you could turn on visibility of a text box that says "ESP TOO HIGH," you could use that actual ESP to lookup from a fan data table and if 1.0" of static is achievable, report the CFM from the lookup table and then determine whether actual CFM is too high... Instantly validate and schedule your performance... I think this might be the next step for instance-based mechanical equipment smart families.

Imagine having one exhaust fan family, with multiple types (downblast, upblast, tubular, etc) and the family can use actual CFM and actual ESP to instantly size that fan, model it, schedule it... you name it. Imagine having one pump family, "" "" (base-mounted, inline, vertical split-case, etc)... Manufacturers who want to see their products on schedules more often should be very interested in this idea.

Thoughts and opinions? I'd love to see this implemented, hope you can throw me an upvote.

[evgeny.kurbatov]

If I understand your question correctly this might help:

https://forums.autodesk.com/t5/revit-mep-forum/zero-pressure-drop-air-terminal/m-p/9848773#M74515

[Paul_Rhiannon]

Sorry, no, I know that duct static as a parameter (presently) needs to be put in by the user, or defined by a formula... I'm asking if Autodesk would consider making it a "calculated in" parameter similar to CFM, so that the static pressure calculated by the duct system will feed into the family as an instance parameter.

Rereading my original message, I realize I didn't word it very well... guess I phrased it more like "how have other people achieved this?" But really the end goal is that Autodesk would need to implement this in order for it to not be a Dynamo script.

[HVAC-Novice]

One issue would be that you then rely on REVIT calculating correctly. Some fittings, plenums etc. may not be correct and as the designer you keep that in mind when you apply your safety factor. 

I guess you could add a safety factor in the family and then automatically select a larger fan. but this would take a lot of design creativity out since a larger fan may be much less efficient, or more efficient. I think as a engineer I would do that manually. 

I usually design the ductwork and then select the fan or unit size based on manufacturer selection software. If ductwork changes, this usually is based on flow changes, which would require a different fan/unit anyway.