Designing a Ducted Return System for Mechanical Course VDCI

Welcome back to the VDCI course content for the mechanical course. In the previous video, we put in a rooftop unit and started laying out this space down here, the supply system and ducted return. In this instance, we're not going to be using a plenum like we did on the other side, but we're going to be using a ducted return.

So what's going to end up happening if I look at this in 3D, I'm going to actually create kind of a little plenum with the supply. So I'm going to go ahead and pull this guy down. And sometimes it's better to do this in section.

It can become somewhat unstable sometimes when you do this, or I could take this and let's say I change it to 13 feet. It's going to extend it down. So that's another way of doing it.

What I'm going to do is I'm going to go here to my ceiling mechanical. I'm going to go ahead and take a 10-inch duct and have a VAV right here. And we're going to come back to this guy.

So what I'm going to go ahead and do is I know that this duct, that's the duct, the lower bottom elevation is at 13 feet, right? Because it's going vertically. So let's take a look at this in section. Sometimes it's easier to just draw this in section.

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So I'm just going to go 90 degrees. I'm going to come here. Let's look at this in section.

So you can see my ceiling here is still pretty low. I still have a nine-foot ceiling, and this is another ceiling here. What I'm going to go and do is I'm going to bring this guy down and I'm going to just tap straight off of this.

So what I'm going to do is architecture—or excuse me, systems. I'm going to go duct. I'm going to go round duct this time.

So tap short radius. I want to go 10-inch here. I'm going to pick on this edge and just draw over.

Now it switched me over to a 24-inch diameter. Let's see if we can get it to be a 10-inch. Okay.

We'll just draw it in and then we'll change it to a 10-inch. Sometimes Revit wants to think it knows what it's doing. And then I can go ahead and bring this guy down.

I'm going to go to my ceiling mechanical plan. We have that nice guy there tapping off and then we need something to serve all of this down here. So I'm going to tap off here with another, let's say about a 14-inch or so.

So duct. I'm going to go, let's say a 14-inch. Boom.

Come down to here. We'll come down, get into this room, put the VAV in there in a minute, and then we'll work our way all the way down. And then this guy is going to serve all of these ones up here.

We might adjust the routing of this a little bit, just to make it a little bit easier. So I'm going to go ahead and come here, maybe 45 over so that I can find the 45-degree snap so it's a little easier. Then here we are.

We need to go ahead and include a VAV for all these rooms. So I'm going to come over here, grab one of my VAVs, reuse that, create similar. Let's take a look at this in section.

So you can see that it's not lined up. So I can just use my align command to go ahead and line that guy up.

I'm going to go back to my ceiling mechanical plan. I'm going to use the split command (SL), place it here, drag it over to there, place that here, drag it over to there. And that connects that all up.

I need to get rid of that little split. And there we go. That's all good.

Perfect, now let's view this in section. So you can see how this has a little bit of a slope to it.

Sometimes that happens because of how Revit functions, maybe the connector is not the exact same elevation. A lot of times when I have that happen, what I'll end up doing is I'll draw a little piece of duct out of here. Actually, this is the wrong type, so I'm going to use match properties here.

I use MA there to there. Perfect. And then I'm just going to go ahead and get this guy aligned properly.

And there it is. I have that little union there. Let's take this guy, put it in there.

Boom. Perfect. Let's look at this in 3D.

So you can see we've started laying out our runs here. I'm actually going to take this guy. And I'm actually going to go ahead and put this at a decent elevation.

So let's say this is 11' 10". That should move most of that system up. There we go.

Perfect. I might do the same thing here. This one's also going to go to 11' 10".

And there we go. I'm going to go back to my ceiling plan. I'm going to create my VAV for this run.

There we go. Put it in. I'm going to go ahead and split it.

Drag connect there. That gave me that slope again. When you see duct or a pipe with this little symbol, that's a slope.

I'm going to go ahead and take that there. We're going to go ahead and fix that. See, I can change this back to a zero slope by just clicking it and editing it.

Let's go ahead and draw a little piece of duct coming out. I'm going to use that match again. So MA again, MA is match properties.

I select what I want to be the copy, and then I paste it over. Now this is a round duct. Drag over.

There it goes. Well, it gave me a slope again because I didn't go into my section and change it. So let me go ahead and go to my section.

Don't click. So you can see we're still above the ceiling level here. That's good.

I'm going to go ahead and use the align, align with this center line. And there we go. Perfect.

Now I'm ready to create my taps off. We're going to have to work out some of these. We might actually move these diffusers around a little bit because I can't really get a diffuser back over to here.

So I'm going to slide some of this stuff around just a little bit. I'm going to actually move my return and move my supply. I'll put the return like back here in the corner.

Still works. Let's go ahead and do that. And sometimes the routing isn't ideal.

I'm going to actually slide this guy up against the wall a little bit. I can't slide it too far because then I come off my tap. So this location is actually really governed by the tap there.

We'll look at that one in a second, but I'm going to go ahead. And I can use this, I can go CS. Now I know this isn't the final size that I want, but once I use the create similar, I can then change my size.

And I'm just going to come off with this kind of straight. We will come off here, off here, here. Actually, what I'm going to end up doing is I'm just going to take this and go like that.

So that then I actually turn that end there. Same thing down here. I'm actually going to do all these at a 45.

Let's just say that this is going to be a different type of system setup. So I'm going to do all these at a 45. So you can see how it just automatically calculates that for you.

The one thing you have to remember is if you draw this too short, it's going to not allow you to auto route. So you want to make sure you give it a decent amount of length so that it does that. Here, we'll 45 down like this, and it automatically puts the fittings.

There we go. Now I can go ahead, draw flex duct, draw the flex duct between the connectors. When you see the little symbol, the little circle with the X, those are really like the connector snaps.

So you want to make sure when you're doing MEP work in Revit, that you're connecting to those connectors. Perfect. We got a little flex duct here.

So I'm just going around drawing the flex duct. Not a big deal. And there we are.

So this one might get a little complicated. But what we can go ahead and do is I'm going to slide my VAV back a little bit, make sure I have a decent amount of run here. I actually might move this diffuser again.

We're continually adjusting things. It's a design process, always changing, always adjusting. There we go.

Draw flex duct. Boom. There it is.

Now what we'll need to go ahead and do is I'm going to pause this video here, but then we're gonna come back and do the return. See you then.