# 3 - Check and Edit the Building Envelope

## Script Preview

In the previous video, we mentioned how we would circle back to the envelope inputs in the LEED-based building. Let's take a quick look at those and we will bring in the 90.1 screen as well. This is from 90.1

2007 for climate zone A. Let's just look at the non-residential roof construction. We can see 0.048 for the U value with lightweight assemblies.

For the roofs, we are supposed to have insulation entirely above deck which is 0.048. That's good. Let's take a look at the walls above-grade walls, 0.065. This is steel-framed.

It's 0.064. If we dig deeper, we will find out that 0.065 is rounded. The fact that 0.064

and 0.065 are that close won't be a problem. We can continue moving on with those but all of those tend to look correct. We mentioned that the glass may have a problem.

We used metal-framed glass just for whatever reason because it was the default. This is the 90.1 2007 standard but many of these numbers stay the same in other standards. You would have to check to ensure that we don't want to waste your time going through all of it.

Metal-framing, all other metal-framing curtain wall, there are various numbers. All of these are supposed to have a solar heat gain coefficient of 0.4 and the U values are listed here. The problem with E-Quest is that it doesn't use a U value in the setup.

It uses a glass conductance and then it adds the air films to that when it simulates. The shading coefficient simultaneously is different than the SHGC. You have to multiply the shading coefficient by 0.86. Let's take the calculator here.

0.47 times 0.86 is 0.4 with some change. If you recall what we just saw, we can see the SHGC is correct.

The glass conductance, however, we can look at the topic help, select glass conductance, and we can see the U value that corresponds to various glass conductance. We're at closest to this one and that corresponds to somewhere near 0.5 and we can see that depending on which metal framing that we have in our baseline, typically looking at metal framing all other, though it could be curtain wall, we're between 0.45 and 0.55

for the U value. That looks close enough to correct, I should say. The only way to check the U value in E-Quest...

We'll view the detailed simulation output file and I had already jumped to the LVH, the details of the windows. This here has the center of glass U values. It has the shading coefficient, which we already checked. The center of glass U values is somewhere in between the curtain wall and the all other metal frame.

We could edit this until we had an exact number, but the first thing we want to ensure is we want to go to the glass and ensure what type of glass it's supposed to be. Here we have the frame as metal framing all other, which corresponds to 0.55...

Typically, it's not always going to use more or less energy by changing the U value slightly. Likewise, if we look at the glass doors, we have a 0.725, whereas the U value is..

You could edit these. We have some libraries to import where we did edit these, and they're slightly more accurate. However, that requires a manual step of importing them and implementing them. It appears that the windows have been imported with the correct glass shading coefficient, and the center of glass assembly U value is a center of glass and assembly because there's no frame.

This is permissible by standard 90.1 compliance programs. If you wanted, you could further edit this. You could edit your glass type.

For example, look at the glass conductance, and we could raise this by something like...

Let's just rerun this just to show you. That was LVH, Details of Windows...