Designing Exhaust Systems with Rigid Connections: A 3D Overview

So great, we've completed laying out our exhaust systems. Again, kind of one thing here to mention is that the connections to the diffusers for the exhaust system are actually a rigid connection. Over on our supply systems, we use that flex duct, which is represented here, to create the connection between the duct and the diffuser.

In some locations, or in some projects, you may have to have a rigid connection to every piece of, or every diffuser from the duct. But traditionally, a lot of the projects may have just the exhaust being that way. So let's take a look at this in 3D real quick before we move on.

So I'll get in 3D. So you can see here, you can see how my flex duct, it kind of moves around. But then in my exhaust system here, we went ahead and we have the rigid connection.

So it has the diffuser itself. Then there is a transition piece, because since this is a 12 × 12 rectangular connection, we'll need a transition to go to the round. We have the round, a short run of that vertical duct.

We have a radius elbow there. We have the other portion of the tap coming off of the main trunk line. And then we have the tap into the main.

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Great. Now we want to go ahead and connect this system, but we kind of, it's easier to do it in section. So I'm going to go to my level two sealing mechanical working.

Then I'm going to go ahead and cut a section. I'm going to go ahead and cut it kind of, we'll go horizontally, left to right. So I'm going to go here, section.

And this is kind of kind of just be a working section. Now I could just grab the section that I have over here. If I wanted to, I kind of don't know, well, it went all the way down here.

I always like to have kind of a couple working sections, because maybe I need to come back to this area to clean stuff up. And I don't want to keep moving this section around. But just be aware, you don't want to create too many working sections, because the more views you have in Revit, the more things it has to think about, and it can slow things down.

So one, one of the best practices I've kind of been telling people is that if you have a lot of like these working sections or working views, kind of go through, clean them up, remove them, because the more views Revit has, the larger the file size and the slower it can run. What I'm going to go ahead and do is I'm going to come into this view by double-clicking on the section head. And there we go.

Now you may notice that the ducts that are running parallel with our view are just a single line. And that is a function of the detail level. So at a fine or a coarse detail level, ducts will represent with just a center line.

And this is so that people can make single line diagrams, those kinds of things. The profile of it, where the duct is being cut, will show with the overall size. So I'm going to change my detail level, because I always like to work in like a fine detail level, so I can see the different components.

And you can kind of see what happened here. If I change this back to coarse, let's just take a peek at this. Notice how my walls are just kind of basic.

There's nothing super crazy there. They're just kind of these solid forms. There's no division of materials.

My ducts are single lines. If I change this to a fine detail level, you can see now I see the duct here, I see the diffuser, and then I start to see the finishes on the architectural elements. So you can see I have a gypsum board layer here, a gyp layer, a gypsum board layer, and then a metal stud layer in there.

So what I'm going to go ahead and do is I'm going to create a vertical going between these spaces. So I'm going to go duct, I'm going to draw it off the side for right now, I'm going to have it be that same tap short radius, I'm going to have the system type as exhaust air, but I want this to be a 16 inch duct. So I'm going to go ahead and change it to 16.

And really the duct sizing. And if you've gone through mechanical engineering, really relates to the total amount of air that you're moving. So that's kind of how we're getting some of the duct sizing here.

What I'm going to go ahead and do is I'm just going to draw it off to the side. Now the one thing you kind of have to remember about this is that it may not necessarily be in plane with your other view. So what I'm going to end up doing, I'm going to actually make sure I'm going to go a little bit longer, just to make sure it's showing in my ceiling plans, I know it's going to show on my second floor ceiling plan.

But on my first floor ceiling plan, I want to make sure it kind of comes down a little bit. I'm going to go over to my working ceiling view. Here we go.

And see where this guy is. So see, when I drew it in that section view, the work plane of my section view is actually going to be where that section cut is happening. So I kind of want to get this back here into the shaft.

So what I'm going to end up doing is now that I have it drawn, I'm just going to go ahead and move it back here. And there we go. So I just grabbed it, I can just select it and move it.

So sometimes I've just found that it's easier. I'm just going to get it drawn, I'll get in the right location. You know, obviously, you know, it's easier sometimes to put it directly in the right location.

But sometimes there's not good snaps, or not a good way of doing it, it's just easier. Let's put it in, we'll move into the right location later on. Now, what we could also go ahead and do is notice how these two do not line up.

So I want to get these to line up. So what I'm going to do is I'm going to go al, I can select the center line of that duct. And then I can select this center line here.

And there we are. So that's an easy way of really kind of making sure that your connections are good. So again, what I ended up doing is I went al for a line, or you can come up here to the align tool, I went to the center line, or the reference point of this duct pick.

And then I picked the center line of this duct pick. And there we go. And it only moves it relative to my plane of view.

So this should still be and let's double check it, this should still be a middle elevation of 11 feet, which it is. So all this ended up doing was it just shifted it over. So it's in line with this, I'm going to go ahead and rotate my section here.

So I can see how these two are coming together. So I'm going to go ro, I'm going to rotate 90 degrees, I need to go ahead and move that guy back a little bit. I'm going to double click into here.

And you can see I can start to see how these ducts are relating to one another. Great. So I'm going to go ahead and trim this together.

Now I know that since I align them, they're in plane in plan. So I can just go trim TR pick here, click on the portion I want to keep, click here. Boom.

Since it has the case, that's the radius. Since the duct here is the tap short radius, it already knows it wants me to put in that elbow from up here. Now we're going to kind of have to see how this fan ties in.

But this is probably not aligned yet. Remember, we did the align on the first floor. We didn't do on the second floor.

Now if I just take this guy and I drag it over, it may make the connection, but you notice it added in some extra fittings here. So what I want to go ahead and do is let's take a look at some of these extra fittings. So I'm going to go to my ceiling to mechanical working.

And you'll notice that it put in some 45 degrees, a short run a duct, another short run a duct, and then it tied into here. I'm going to go ahead and undo. So I just have this.

But what I can do here is I'm going to go AL for align again. It's showing me that reference point, pick, and I'm going to pick the center line. Now you'll notice that the center line is not necessarily showing up.

That might be a VV setting. So what I could do just to make sure I'm selecting the right reference, that's always an important thing in Revit. I'm going to go into VV.

I'm going to go into my ducts and I'm going to turn on center line there. So make sure that this center line is checked. I'm going to hit apply.

I'm going to go ahead and hit okay. So you can see it popped up with the cross element here. And then I have the center line of the duct now represented here.

I'm going to go align, pick there, pick there. Again, it moved all that back. I'm going to go back into my section.

Now when I drag this over and connect it, it's just going to be a straight connection. Perfect. What I want to go ahead and do is I'm also going to give myself some height here so I can tie it into my fan later on.

So what I'm going to do is I'm going to drag this up a little bit and I'm just going to draw a piece of duct. See, there it goes. So sometimes you just have to make sure it's getting the right context.

When I first selected this and then right-clicked, it didn't have draw duct. I just exited out, went back to it and did it again. Draw duct.

There we go. And I'm just drawing that off to the side. That's probably not going to be the final location for it.

It may come back at us, but I can't draw it, but I can adjust and plan really easily. If I go to my ceiling two mechanical working, you can see there. Now I can't necessarily see it because my view range is not high enough.

So what I can go ahead and do is I'm going to go to my view range and I can see up, but we might be, let's go to unlimited and see what's happening. Apply and okay. And you may have seen this little line pop up.

Let me zoom in. I'm going to undo this. Let me do this again.

So edit. I'm going to change my view depth to unlimited. Apply.

Okay. And then notice how that little line popped up so that I can see it because it's kind of above my roof level. We'll kind of see what happens.

We'll take a look at it in the section view. So all I ended up doing was I just grabbed that and then dragged it over here. So again, I selected the short run of duct I drew.

I'm going to drag that over and it's going to make the adjustments necessary to get all that correct. Let's go ahead and rotate our section here. I'm going to go 90 degrees and let's look at it.

Great. So let's take this section up and kind of see what we got looking on for a roof here. So you can see we have the library there.

We have a couple of other items. I'm going to go to our 3D view because we want to find a good spot for the fan, but it looks like there's a clerestory window here. So I'm going to go into my 3D view.

Notice I don't have my architectural model on. I can go ahead and hit VV. I'm going to turn that on so I can see what I'm looking at here.

Apply, hit OK. And so we may not necessarily want to put it on this particular roof because since this is a clerestory windows, we may not necessarily want to put it here, but we could because this is a high roof and there's really not going to be, since this is the gym behind it, it's not going to be that big of an issue. So, or we could also place it up here on this roof.

So you have a couple of different options. We obviously probably would not want to place our mechanical fan on this roof here just because of the slope and everything. It's going to make it for a very, very tough installation.

We'll go ahead and we'll populate it down here on this roof in the next set of videos. See you then.