I'm trying to model a greenhouse (GH) with 4 roof peaks e.g. like this. At this point, for first draft simplicity I'm modelling the GH as a building with a single large window on each glazed surface, and there is a single zone inside.
The issue arises when I try to add the roof windows. The north roof on the north-most peak and the south roof on the south-most peak are fine; all the other windows (like the window on surface "P2RNorth," the northern slope of the second peak) trigger a large number of severe errors, all looking like this:
** Severe ** Problem in interior solar distribution calculation (CHKBKS)
** ~~~ ** Solar Distribution = FullInteriorExterior will not work in Zone=ZONE ONE
** ~~~ ** because one or more of vertices, such as Vertex 1 of back surface=GWEST, is in front of receiving surface=P2RNORTH
** ~~~ ** (Dot Product indicator= 391.8213)
** ~~~ ** Check surface geometry; if OK, use Solar Distribution = FullExterior instead. Use Output:Diagnostics, DisplayExtraWarnings; for more details.
I will need interior solar for gauging the sunlight/supplementary light demand in the GH, so I don't want to default to FullExterior. I've read this and this. I've double-checked geometry, that every surface is facing outward when I expect it to, etc. but no luck.
DisplayExtraWarnings has lead me to my current theory of the issue:
Surface=P1RNORTH is used as Receiving Surface in calculations and is convex.
Number of general casting surfaces=0
Number of back surfaces=37
...Surface=GWEST
...Surface=GEAST
...Surface=P1TRIWEST
...Surface=P1TRIEAST
...Surface=P2TRIWEST
...Surface=P2TRIEAST
...Surface=P3TRIWEST
...Surface=P3TRIEAST
...Surface=P4TRIWEST
...Surface=P4TRIEAST
Number of receiving sub surfaces=1
....Surface=P1NRF-WIN
==================================
Surface=P1NRF-WIN is not used as Receiving Surface in calculations.
Number of general casting surfaces=0
Number of back surfaces=0
Number of receiving sub surfaces=0
==================================
Surface=P2RNORTH is used as Receiving Surface in calculations and is convex.
Number of general casting surfaces=1
..Surface=P1RSOUTH
Number of back surfaces=37
...Surface=GWEST
All the surfaces that trigger the error when they get a window (like P2NORTH) have casting surfaces, while those that are error-free (like P1NORTH) do not have casting surfaces.
Are these casting surfaces what are causing the issue for InteriorSolar?
If not, what else might be causing the errors for some surfaces but not others?
If so, is there any way around this issue that would allow an accurate solar light representation with such a geometry? It seems like "part of a building casts a shadow on a window on another part of the building" is a common enough geometry that it shouldn't be a showstopper...
