topic Re: Struggling with Connecting Multiple Vertical Ducts into One and Vice Versa in Revit MEP Forum

Struggling with Connecting Multiple Vertical Ducts into One and Vice Versa

tim102289 — Wed, 20 Mar 2013 20:17:43 GMT

I have a project I am working on where there are multiple floors, and we have a chase inside of which we are running the duct down from the unit on the roof. Each floor, a little bit of duct peels off using an elbow. The rest of the duct continues down to the next floor. However, because the section that peeled off is a corner of the vertical duct, I have to take 2 ducts down to the next floor. My problem, is that I would like these three ducts to combine into one big duct to go up to the floors above. I know this is probably confusing to udnerstand the way I have worded it, so I've included a color-coded screenshot to hopefully explain better.

Re: Struggling with Connecting Multiple Vertical Ducts into One and Vice Versa

Anonymous — Thu, 21 Mar 2013 15:18:48 GMT

You can create custom duct fitting(s) with multiple duct connectors whereever individual ducts split from big duct and a connector for the big duct.

Big Purple R --> New --> Family

Select duct fitting category and make part type: multi-port in the family categories and parameters menu.

...

Make as many as you need. If you know these custom fittings are "similar" to each other in shape and want to get fancy about it, you can create (1) family with a bunch of instance parameters that you can modify values in your project.

Re: Struggling with Connecting Multiple Vertical Ducts into One and Vice Versa

Anonymous — Tue, 02 Apr 2013 22:35:19 GMT

can you share the fitting family?

Re: Struggling with Connecting Multiple Vertical Ducts into One and Vice Versa

Anonymous — Tue, 02 Apr 2013 22:37:00 GMT

I am looking at this.

Thank you.

Re: Struggling with Connecting Multiple Vertical Ducts into One and Vice Versa

tim102289 — Mon, 08 Apr 2013 17:05:10 GMT

If anyone is good at making families, could you create a duct fitting that splits a duct into 2 ducts? I basically would just need a duct fitting that allows you to specify the size of the duct going in on one side, and the size of the two ducts coming out the other side. The fitting would be the same width and height the entire way, but just split into two pieces on one end. So for example, if the duct coming in on one side was 30x14, the two ducts coming out of the other side would add up to that, say, a 10x14 and a 20x14, and all ducts would continue straight, parallel with the original duct, no curves, tees, angles, etc. I made an attempt at this but it didn't work out. It would also be nice if the fitting matched to the size of the duct you place it on, just like transitional tees currently do. When you attach a tee fitting, it matches to the duct you select, and then you can change the size of the two ends coming out.

Re: Struggling with Connecting Multiple Vertical Ducts into One and Vice Versa

Anonymous — Mon, 08 Apr 2013 18:43:44 GMT

I made an attempt at this but it didn't work out.

You can post a picture of it and people can give suggestions on what to do to it. Next time when you have to create another duct fitting, you have learned from your success (and initial failure) of this one.

Re: Struggling with Connecting Multiple Vertical Ducts into One and Vice Versa

tim102289 — Tue, 09 Apr 2013 15:12:36 GMT

I've attached the rfa file for anyone who would like to take a look and offer insight. I think it might be better to take an existing fitting, such as the "Rectangular Wye - Curved - Transition" and adjust it to what I'm trying to create, or use that as a guide.

I essentially created 3 reference planes, Left Trunk, Right Trunk, and Branch Split. Then I made some parameters, trunk height and width, branch 1 width, and branch 2 width. Then I tried to create dimensions accordingly, so that the sweeps would adjust. The trunk width goes from the left trunk reference plane to the right trunk reference plane, and I made another dimension making both sides equidistant from the center. Then I made a dimension for branch width 1 goign from the left trunk reference plane to the branch split, and I tried to do the same with branch 2 width from the right trunk reference plane to the branch split, but it would not allow that, saying it would "overconstrain the sketch". Things seem to adjust somewhat correctly, but I need help getting all the dimensions to work properly, and setting it up so that when you load it into a project and try to place it on a duct, the trunk size will match automatically, and the two branches will start off as totalling the size of the trunk. If we can accomplish this, my next goal is to make other types of this one which would allow for 3+ branches. I appreciate any and all feedback/suggestions.

EDIT: I was also curious if there was a way to delete reference planes already in the template I began with. As you can see from the floor plan view, there are a ton of extra reference planes that I don't see the purpose of.

Re: Struggling with Connecting Multiple Vertical Ducts into One and Vice Versa

Anonymous — Thu, 11 Apr 2013 05:22:54 GMT

I think it might be better to take an existing fitting, such as the "Rectangular Wye - Curved - Transition" and adjust it to what I'm trying to create, or use that as a guide.

You have something much more complex than a wye. When it comes to more complex duct fittings, I usually start from scratch and categorize: duct fitting | type: multi-port so REVIT doesn't do anything funky with it.

As you can see from the floor plan view, there are a ton of extra reference planes that I don't see the purpose of.

Yeah. You got a lot of planes there. Not that anything is wrong with that, except they should be used in some way in constraining and modeling your fitting (or at least as a marker of some sorts).

setting it up so that when you load it into a project and try to place it on a duct, the trunk size will match automatically, and the two branches will start off as totalling the size of the trunk.

I recommend you abandon this goal (as good as it may be). Create a standalone fitting where you manually connect the main duct into.

Some suggestions:

You have vertical ducts --- you should create connectors at top + bottom.

Where the 2 ducts peel of at the 6th floor --- looks like a common large elbow then blue + purple ducts split (or 2 separate small elbows for blue and purple ducts)?

A sketch of a section would be nice.

Here's my guess at what you're trying to achieve:

Re: Struggling with Connecting Multiple Vertical Ducts into One and Vice Versa

tim102289 — Thu, 11 Apr 2013 13:19:01 GMT

I honestly don't think that I do have something much more complex than a wye, in fact possibly simpler than a wye. All I essentially want to do is have a connector, where one duct goes into the connector, and two come out, just like a wye, only no turns. You are proposing one fitting to take care of the entire area, whereas I just need this one fitting turning one duct into two, and the rest of the sections can be modelled using existing connectors such as elbows and straight ducts.

setting it up so that when you load it into a project and try to place it on a duct, the trunk size will match automatically, and the two branches will start off as totalling the size of the trunk.

I recommend you abandon this goal (as good as it may be). Create a standalone fitting where you manually connect the main duct into.

I don't think this goal is really that lofty, unless the fittings packaged with Revit are extremely difficult to construct. Tees and wyes that are already existing match to the duct you connect them to, and then you can change the width size of the 2 branches to fit your needs, which is all I would like this new custom fitting to do.

You have vertical ducts --- you should create connectors at top + bottom

I know I did not mention this in my previous post, but this fitting would be needed in multiple places, for both vertical ducts and horizontal ducts, which shouldn't matter, you can use the same fitting in both places. I'd prefer to create the fitting for a horizontal duct, and then just rotate it as necessary when placing it on a vertical duct.

I've included a very crude sketch, similar to the picture you posted, showing how you could use the fitting I am proposing in three different places, and then all of the rest could be modelled with elbows and straight duct. I tried to use similar colors to your model, and the grey planes would be the locations of my fitting. Again, please excuse how crude it is, I sketched it up in Paint, but I think it gets the idea across.

The red duct splits into red and yellow, the grey duct splits into blue and orange, and then the blue duct splits into blue and purple.

Re: Struggling with Connecting Multiple Vertical Ducts into One and Vice Versa

Anonymous — Fri, 12 Apr 2013 06:24:58 GMT

Nice sketch in paint. That's much easier to understand than your original sketch (to which I matched the colors) where it looked like you were going to split all ducts with 1 fitting. You're splitting the ducts twice (1. red into red + yellow, 2. grey into blue + orange) before the final split (blue into blue + purple). Here are (2) more attempts:

Re: Struggling with Connecting Multiple Vertical Ducts into One and Vice Versa

tim102289 — Fri, 12 Apr 2013 12:24:31 GMT

Yes "Fitting X" is essentially what I would like to do, and to have it be parametric so that it can be used for various sizes of duct. Would you be able to make an rfa file or walk me through it?

Re: Struggling with Connecting Multiple Vertical Ducts into One and Vice Versa

Anonymous — Tue, 16 Apr 2013 04:27:06 GMT

I couldn't get fitting X to split the duct into 2 ducts automatically. I could get it to automatically resize to the big duct and connect it to the end of the big duct.

Plan View:

Front View:

W1 is the user editable parameter and W2 is calculated by: W2 = W - W1. You don't see W2 because it would over-constrain the fitting. I recommend centering the fitting to the 3 default planes. Don't forget to constrain the dimensions of the 3 duct connectors.

Re: Struggling with Connecting Multiple Vertical Ducts into One and Vice Versa

tim102289 — Wed, 17 Apr 2013 17:07:24 GMT

Can you post the family file you created for me to look at?

Re: Struggling with Connecting Multiple Vertical Ducts into One and Vice Versa

Anonymous — Thu, 18 Apr 2013 01:13:35 GMT

Would you be able to make an rfa file or walk me through it?

I'll walk you through it.

Sketch Fitting X on paper along with any dimensions associated with it.
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Create 6 new instance parameters of lengths. 5 of them are user input, and 1 is calculated by formula. In my example, the 5 inputted parameters are W, W1, D1, D2, and H. Give these 5 parameters some initial values. The parameter calculated by formula is W2 = W - W1.
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Create 7 new reference planes. 2 new reference planes are parallel to the left/right plane (going up/down), 1 new plane to the left and 1 new plane to the right of that default plane. 2 new reference planes are parallel to the default reference level/plane (go to an elevation view and place them there), one plane above the reference plane and one plane below the reference plane. 3 new reference planes are parallel to the front/back plane (going left/right), 2 of them above the default plane and 1 below the default plane.
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Now dimension the new planes with respect to the default planes. The 2 reference planes going up/down and parallel to the left/right default plane are D1 and D2 away from the default plane. The 2 reference planes parallel to the reference level (horizontal) are equadistant from the reference level and H away from each other. Finally, for the 3 planes running left/right (parallel to front/back default plane): the top and bottom most planes are equadistant from the default front/back plane and W away from each other. The 2nd top plane (the new plane plane above the default plane) is W1 away from the top plane.
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Now that you've created and dimensioned all of the planes, it's time to make 3 extrusions. Set the working plane to the new horizontal plane below the default reference level/plane. Create the top left extrusion (as seen in plan view), and either lock or dimension 0'-0" away from the planes that make up that piece of fitting. Set the extrusion end to be H or lock it to the new horizontal plane above the default reference level. Repeat this process for the bottom left piece and the right piece of the fitting.
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Now place new duct connectors (all set to global) to the 2 faces on the left end and 1 face on the right end. Constrain the heights of all those connectors to be H. Constrain the width of the top left connector to be W1. Constrain the width of the bottom left connector to be W2. Constrain the width of the right connector to be W.

That should be it. Make sure it's set to a duct fitting category in the properties. Save and load into project.

Re: Struggling with Connecting Multiple Vertical Ducts into One and Vice Versa

tim102289 — Thu, 18 Apr 2013 13:59:09 GMT

Thank you so much for all of your help! I will probably make some other types to go with it, branching 1 into 3, as well as some others.

Re: Struggling with Connecting Multiple Vertical Ducts into One and Vice Versa

Anonymous — Thu, 18 Apr 2013 22:46:23 GMT

No problem. There are infinite different ways of making the fittings you want.

Re: Struggling with Connecting Multiple Vertical Ducts into One and Vice Versa

tim102289 — Fri, 19 Apr 2013 15:32:44 GMT

Yep. I just don't have a lot of experience with making families, just working on projects for the most part.

Re: Struggling with Connecting Multiple Vertical Ducts into One and Vice Versa

Anonymous — Mon, 23 Feb 2015 15:40:42 GMT

Hi!

Great explanation!

I followed the steps on Revit 2015, placed the fitting in my project, but I get an error (Can't make type "M_Rectangular FittingX") when I try to rotate the fitting.

Can you help me with this?

Thanks

Lawrence Lasmar

Re: Struggling with Connecting Multiple Vertical Ducts into One and Vice Versa

projetos7RKLZ — Sun, 17 Mar 2024 01:11:41 GMT

11 years later, but thank you very much!!! I was wondering how to do it for a few days already.