Converting Breps to HB_Surface

Hi @mostapha and Dear Community

I want to convert my Breps to HB_Surfaces and I need them instead of surfaces on modeling because this is the shading effect of bricks on the wall but when I use Breps there is an error which says “1. All of your HBSrfs must make a closed volume.”

The effect of Khavunchini on heat (960.9 KB)


Hi @Nariman.Rafati,

Have a look at this video series.
It will tell you something about the principles of energy modeling with honeybee. Rooms have to be closed breps. Physical materials are just text definitions, you don’t have to model them in 3d. I put an example in your .gh file.

The effect of Khavunchini on heat (1015.7 KB)

Hi @Erikbeeren Thank you for your response.

I know, but what I am working on is the effect of its volume on thermal comfort so it has to be a part of energy modeling at first instead of shading context, because that component doesn’t take EP material.
Although my volume is closed this error warn me and I don’t know how to solve.


hi @Nariman.Rafati

Are these elements a sort of chimneys belonging to a space below?
Have a look at these examples. (511.7 KB)

Your volume is closed but not defined as a closed Brep. That is what is giving the error.

Hi @Erikbeeren

No these are just two simple rooms on the roof.
I saw your example model, in your model the walls and roofs are surfaces. because of the experiment, I don’t need them as surfaces, I need the south wall has its specific shape and volume, we call them “Khavunchini”, as you see the outer south wall area in these two rooms are different from each other and I want to analyze that is there any effect with this pattern and the shadow they make on the south facade that is related to indoor air temp and inner surface temp?


Hi @Nariman.Rafati,

Thats quit a detailed simulation. Still you have to define your room as a closed brep. Otherwise you will get an error.

I doubt the results of the two “Khavunchini” will be very different. The total amount of sun falling on both surfaces will be exactly the same. Only the amount of mass will differ a little bit.

You could try to set the brick patern as a shade in front of the south facing wall, but then you would ignore the conductivity of the shading material.

Perhaps you should have a look at the Therm components (steady state simualtion).

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@Erikbeeren Thanks for your response.

Exactly the experimental results told there is a little different. if you look at the model the volume is closed but I still get this error and I don’t know why!

I tried another way in which the walls and roofs where surfaces with defined materials and kept just two horizontal surfaces of each brick of pattern on the model but want to define the model more accurately where I should use the geometry as extrusion, not surface in energy modeling.

I am still searching for this problem and error.


The volume is closed but not defined as a closed brep! So Honeybee does not know it is a closed volume.

So how can I turn it to closed breps?

You have to define your “Khavunchini” as a brep first (just a box)
You can explode it and then define all materials.

Then you can put the surfaces together agian. It will work!

I Think in this way i should take the outer surface and I am still using a surface.I did this at first but the result was different from experimental results.

What you want is realy detailed. I think energyplus is not suited for this. The difference could be the result of turbulance, moisture transport or whatever. For these sort of simulations you will need MATLAB and a lot of know-how. It would be nice to put a lot of sensors in and around the “Khavunchini” to see what actualy is hapening. A nice arduino project!

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@Erikbeeren exactly you’re right. Thanks for the help I’m still working on it :sweat_smile:.

Thanks for the reply, as I had the same issue.
Can I ask why one connection from HBsurface to the HBzone is dotted line whereas the other two are solid lines?

Hi @Hyacinth2020,

Here you can find more information.

For this case it does not matter. All data is flattened befor the brep (zone) is made. (see point 1 in image below)

However if you have two BREPs you should be carefull about this. All surfaces in one list (double line) will be put together into a single zone. So to create a two zone geometry you need two lists of surfaces put together in a data tree. (dotted lines).