Question about window group definition for interior shade, glass, exterior shade setting

Dear all,

While working on a slightly complicated case for shade control, I encountered an issue about defining the window group:

We have a room in a shape of a box, 1 window facing south with dynamic blinds, 1 skylight as static. The South window has 1 layer of interior shade, and 1 layer of exterior shade, with glass in between. The control rule is when sensor A (interior on the north wall) exceeds 250 lux, close the interior shade; when sensor B (close to the window to test direct sunlight on the south window) exceeds 5000 lux, close the exterior on top of interior shade. (I’m not sure about how multiple sensors should work and posted the question here: Window group states and sensor ) If unsolved, assume only sensor A rules.

How should we model the window group in this case?

My understanding is, ideally, the “interior shade- glass - exterior shade” should be 1 window group, with 3 states: 0 glass only as BSDF; 1 glass and interior shade as BSDF; 2 glass, interior shade, and exterior shade all together as BSDF material. In the case the blindCombs will be:

However the challenge is we usually only have BSDF material for each (glass, interior shade, exterior shade), but not combined. So we may need to have this as 1 static window with 2 window groups?

In that case, the window group definition will be: static window with glass (written in Glazing in scene folder, together with static skylight); window group 1 interior shade with 2 states (clear or BSDF interior shade); window group 2 exterior shade with 2 states (clear or BSDF exterior shade); In the case the blindCombs will be:

Which of those 2 methods above would work for modeling window groups? Or am I understanding this wrong?

I set “write” to true and read the report from runRadiance. Then I noticed that it recognize objects with BSDF material as Fenestration no matter it is connected to HBObjects input via HBSurface or HBWinSurface. In this case, if the interior shade is always down, can I set this interior shade with BSDF material as Context Surface instead of HBObjects input? I also posted the question about context here: Definition for Context in Honeybee[+]

Any advice or suggestion would be much appreciated! Thanks!


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Hi @Xiufang.

Your understanding of window groups and control strategies is correct.

Yes. That’s how it should be done.

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Thanks @mostapha! So it means both methods (modelling two shades and one glass as 1 window group vs. modelling them as 1 static and 2 window groups) are correct but it depends on what BSDF material is available?