# 4-1 Shell Stacking Advanced

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4-1 Shell Stacking Advanced

In this tutorial, we are going to cover a quick walk through of shell stacking. We are creating a quick default project to illustrate this. We will stick to the defaults since we only care about geometry here.   Let's look at our first shell We are just going to make it 1 floor and keep the defaults. And we are ready to create our next shell. We are not going to copy the previous shell. This shell is going to be 1 floor as well and we are going to change the square footage to 10,000.

Let's specify the exact coordinates. We can select immediately above but the real challenge is setting the coordinates because they take precedent over the shell position. Enter 0, 0, and 12, because the first shell was 12 feet tall. The result of this is that the southwest corners of the shells align.

Now we move onto the next screen. The dimensions are 100, by 100 because we entered 10,000 square feet. We will change them to make this shell smaller. We will try some options and decide to enter 50 and 50. You can see that this makes a change visually as we make our edits but we settle at 50 by 50 and we are going to return to the navigator.  We need to make a few changes to shell 1. We set the roof to adiabatic and go back to shell 2. We will set the floor to "over conditioned space" and return to the navigator.

Now, we can view our newly created building. So we click finish. It generates the file. Then, we view the 3-D Geometry. And you can see what we were going for. The shells are aligned at their southwest corners We need to add a roof to much of the lower shell. Left click and select part of the southern zone. Then we will create a child exterior wall. We will just copy an existing component. We will stick to the default construction that shows up. We need to set the location to top, leave all the other defaults, and then we can click done.

Selecting this new roof, we can see it highlighted. To be consistent, we will set this to a roof construction. The real issue is that the roof extends below our other shell, which is incorrect. To fix this, we need to identify the polygon, "El1 Space Polygon 1" Then we select the polygon. We select El1 Space Polygon 1 and we create a copy. We cannot edit "Space polygon 1" because it is used to define the space. Thus, editing it directly, would ruin this zone.

We will select this new polygon. We will go back into 2-D geometry and click this option so we can edit the polygon. Then we will click edit. This allows us to edit just like drawing a CAD file. We can make a guess and see how we do.

We will just move this point to the right. We can also do this by changing these numbers here. We will try 25 and 25. You can see the changes visually. We can click done on the control bar and select yes when prompted to save.

Go back into 3-D geometry and select the roof. Open the properties and change to the polygon to polygon 16. We have to select the roof again. Note that there is still overlap. Open polygon 16 to enter the exact dimensions. The top shell was 50 by 50, so we enter 50 in place of 25. Now when we select the roof, we can see that it aligns perfectly. We can add the remaining roofs in a similar fashion. Now we just need to add these roofs. Make sure to select the plenum space. Then create the child wall.

The East and North roofs are simple. They Just need to be added as normal. It would probably have been easier to add the roofs in the wizards And then edit them Instead of adding them this way but this method is more clear for demonstration. As always, the inputs for your building will be up to you.

Now we have to add the west wall. We will start by creating the wall/roof as normal. We simply select the plenum space. Then We create the child wall again and make it a roof. Then, put it on the top. We make a note of the polygon. Now, when we select this roof, we see the same problem as before where the roof extends below the top shell. We look at the new roof again, and we can note which polygon it uses. Copy the polygon again. To get polygon 17. This time, we can just change the geometry here. We subtract 50 from 158.1. That gives us 108.1 From experience, we note that vertex 3 will also use the same x value of 108.1 So we can enter 108.1 twice.

When we are finished, we click done and check the image. We can select the roof to see it highlighted. We still need to change to the polygon and select polygon 17, which makes the roof appear correctly.

Now we need to complete our central roof. It is difficult to select the plenum zone. We will simply select the core plenum zone on the left. Create a child wall again. Proceeding here as done before. Again, we select top. Note that it uses space polygon 5. Copy this polygon as before. Its name will be polygon 18. It would be difficult to edit this polygon here because the new polygon has 6 vertices. It's possible, but we can click done. Go to 2-D view to make the edit. Select polygon 18. Before we move on, let's switch the roof polygon to polygon 18 as well. We select the space that we need to edit so that we can click here in the control bar. Select polygon 18, which opens the polygon within the 2-D geometry screen. Select Edit. That allows us to make changes, like we do in the wizards. A trick to identify which point is being edited is simply to click that point. We make it a beige dot and move it. You can see the corresponding change in the coordinates. Let's get a rough estimate of our shape. We drag the blue dot to creat another vertex. Note that you still must move counter- clockwise. With two additional vertices, we can fix this. We create a square with a notch in the southwest corner. The purpose of this is really just to create and identify our new vertices, in order to change it correctly in the new coordinate system. And thus, noting the top shell was 50 by 50. We enter 50, in the appropriate places.

The polygon will reflect these changes. We can identify the correct vertex by clicking on it. We make our final changes, and that gives a nice set of square angles. Click done and select yes. Selecting the space, we do not note anything until we enter 3-D geometry. What went wrong? See, the space coordinates begin at 0,0 in the southwest corner even though, the space itself starts at 15,15. Thus, we need to subtract 15 from 50 and change the 50's to 35's.

Now, the roof will appear exactly in line with the 50 by 50 upper shell. This is an eQUEST skill that gets easier with practice.