Question-and-Answer Resource for the Building Energy Modeling Community
 | 1 | initial version |
I'm using Rhino + Grasshopper ecosystem for energy modelling, so my case might not help you.
Firstly, I recommend to output all warnings by setting as follows in your idf file. I'm not sure if it can be set in OpenStudio.
Output:Diagnostics,
DisplayAllWarnings; !- Key 1
Secondary, after running simulation, do you see warnings similar to the following in your err file?
** Warning ** CheckConvexity: Zone="6F_LOBBY", Surface="6F_LOBBY_SRF007" is non-convex.
** ~~~ ** ...vertex 2 to vertex 3 to vertex 4
** ~~~ ** ...vertex 2=[29.12,170.22,37.00]
** ~~~ ** ...vertex 3=[29.12,170.22,49.00]
** ~~~ ** ...vertex 4=[91.15,170.22,49.00]
** Warning ** GetVertices: Floor is upside down! Tilt angle=[0.0], should be near 180, Surface="6F_LOBBY_SRF015", in Zone="6F_LOBBY".
** ~~~ ** Automatic fix is attempted.
** Warning ** CheckConvexity: Zone="6F_LOBBY", Surface="6F_LOBBY_SRF016" is non-convex.
** ~~~ ** ...vertex 5 to vertex 6 to vertex 7
** ~~~ ** ...vertex 5=[91.15,170.22,37.00]
** ~~~ ** ...vertex 6=[91.15,162.47,37.00]
** ~~~ ** ...vertex 7=[91.15,162.47,32.00]
** Warning ** Indicated Zone Volume <= 0.0 for Zone=6F_LOBBY
** ~~~ ** The calculated Zone Volume was=-63155.13
** ~~~ ** The simulation will continue with the Zone Volume set to 10.0 m3.
The negative zone volume in my model was fixed by fixing the "upside down" warning and the "non-convex" warning. For example, if the surface with the warning is rectangle and has 4 vertices in your idf file in the followng order:
Vertex1 X,Y,Z -> Vertex2 X,Y,Z -> Vertex3 X,Y,Z -> Vertex4 X,Y,Z,
please try changing the order in your idf file as follows
Vertex4 X,Y,Z -> Vertex3 X,Y,Z -> Vertex2 X,Y,Z -> Vertex 1 X,Y,Z.
| | 2 | No.2 Revision |
I'm using Rhino + Grasshopper ecosystem for energy modelling, so my case might not help you.
Firstly, I recommend to output all warnings by setting as follows in your idf file.
Output:Diagnostics,
DisplayAllWarnings; !- Key 1
I'm not sure if it can be set in OpenStudio.
Output:Diagnostics,
DisplayAllWarnings; !- Key 1
Secondary, OpenStudio...
Secondly, after running simulation, do you see warnings similar to the following in your err file?
** Warning ** CheckConvexity: Zone="6F_LOBBY", Surface="6F_LOBBY_SRF007" is non-convex.
** ~~~ ** ...vertex 2 to vertex 3 to vertex 4
** ~~~ ** ...vertex 2=[29.12,170.22,37.00]
** ~~~ ** ...vertex 3=[29.12,170.22,49.00]
** ~~~ ** ...vertex 4=[91.15,170.22,49.00]
** Warning ** GetVertices: Floor is upside down! Tilt angle=[0.0], should be near 180, Surface="6F_LOBBY_SRF015", in Zone="6F_LOBBY".
** ~~~ ** Automatic fix is attempted.
** Warning ** CheckConvexity: Zone="6F_LOBBY", Surface="6F_LOBBY_SRF016" is non-convex.
** ~~~ ** ...vertex 5 to vertex 6 to vertex 7
** ~~~ ** ...vertex 5=[91.15,170.22,37.00]
** ~~~ ** ...vertex 6=[91.15,162.47,37.00]
** ~~~ ** ...vertex 7=[91.15,162.47,32.00]
** Warning ** Indicated Zone Volume <= 0.0 for Zone=6F_LOBBY
** ~~~ ** The calculated Zone Volume was=-63155.13
** ~~~ ** The simulation will continue with the Zone Volume set to 10.0 m3.
The negative zone volume in my model was fixed by fixing the "upside down" warning and the "non-convex" warning. For example, if the surface with the warning is rectangle and has 4 vertices in your idf file in the followng order:
Vertex1 X,Y,Z -> Vertex2 X,Y,Z -> Vertex3 X,Y,Z -> Vertex4 X,Y,Z,
please try changing the order in your idf file as follows
Vertex4 X,Y,Z -> Vertex3 X,Y,Z -> Vertex2 X,Y,Z -> Vertex 1 X,Y,Z.
