EUI wrong m2 count (component: HB End Use Intensity & HB Room Colors)

grasshopper honeybee
,
#1

Hi all,

First of all thank you @chris for your two wonderful HB video series. I watched all of it!

Now I encounter something strange and I am wondering if I am doing something wrong of if this might be a bug:

When I was building an energy model of my 300 year old home to find the best improvement possibilities I encountered that the m2 count from the HB End Use Intensity > Gross Floor is wrong. I made a very simplified version of my house to see if this problem persists and its still there. See explanation below the image.

question
question3000×1308 186 KB

The floor area of the simplified model is 25m2 so for 2 floors it should be 50m2 but the result is 75m2; so 3 floors… Also if you look carefully in the Rhino scene and observe the second floor of the HB Room Colors component visualization you see that there are 2 floors, a red and blue one on top of one another. Strange… I guess what I am wondering if this will impact my energy evaluation?

If you look at the grasshopper file below you see that I build the rooms from faces. I know that this can be done much simpler with volumes but I need those faces because in the complete model of my house almost every wall has other layers and properties so this is why I build it like this. I am guessing that the problem might be in there some where. Any help would be greatly appreciate.

Grasshopper file: test m2.gh (71.7 KB)

#2

You’re welcome @david25 !

This is a result of a small misstep that you made in using the Face-by-Face methods for constructing energy model. I see that you have connected the same interior floor face to both rooms:

image
image980×547 79.6 KB

However, for one of these Rooms, this Face should be a RoofCeiling and not a Floor. This results in the bottom Room having two Floor Faces instead of a Floor and a Ceiling:

image
image1583×613 78.3 KB

For a simple case like this, I would highly recommend constructing your Rooms from Solid as you see in the tutorial videos. The Face-by-Face workflows are powerful but they are far more prone to accidental missteps, particularly if this is your first time using them. Here’s a version of your model that is set up correctly with the Room from Solid workflow:

image
image1191×777 74.1 KB

test m2_CWM.gh (47.6 KB)

#3

Thank you very much for your reply @chris!

That is very good to know. I falsely assumed this would be overwritten by the Solve Adjacencies component.

I actually want to use the face by face method because all the exterior and interior walls in the 300 year old house became different overtime. The file I send was only a very simplified version for testing.

This brings me to two more questions:

  1. When I have a floor and ceiling that are 2 faces that are exactly in the same place. What happens when I assign the full floor buildup construction to both them? Is this removed with the Solve Adjencies component? Should I only assign the whole floor build up to the floor OR the ceiling, and leave the other empty? I hope you understand my question.
  2. does the Solve Adjacencies component work when rooms are assembled from faces and a single interior wall face would be used for 2 rooms? Or is it recommended to use 2 different faces, that are exactly in the same place?

Thank you again for your help!

#4

Adjacent Faces need to have construction material layers in reversed order from each other. Most of the time, this does not matter because either the interior construction is symmetric (eg [gypsum, air gap, gypsum]) or people just use the default interior constructions, which are set up to be in reversed order between floors and ceilings.

Yes, you should use two different Faces whenever possible. This avoids the case of having two Faces with the same identifier.

#5

Thank you @chris for your answer!

1 Like