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Does DaylightingDevice:Shelf causing unenclosed zone output inaccurate results?

asked 2018-11-27 12:25:11 -0500

mldichter gravatar image

updated 2019-05-10 14:42:19 -0500

Simulating DaylightingDeviceShelf.idf from the Energyplus 9.0 Examples Files, with an Output:Diagnostics,DisplayExtrawarnings object added, creates a warning

* Warning * CalculateZoneVolume: The Zone="DAYLIT ZONE" is not fully enclosed. To be fully enclosed, each edge of a surface must also be an edge on one other surface.

The Warning continues saying the zone volume calculation is done by

* ~~~ * The zone volume was calculated using the floor area times ceiling height method where the floor and ceiling are the same except for the z-coordinates.

Granted, the proper way to specify a light shelf in energyplus is unusual, but it shouldn't create this warning.


What I really care about though is if this will or will not output accurate results. Is there any way to find out?

Energyplus github issue

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answered 2019-05-09 20:20:51 -0500

mldichter gravatar image

updated 2019-05-09 20:25:01 -0500

I may have a workaround for this, but would like an expert opinion.

I changed the single inner shading surface into two surfaces so they shared edges with another surface.

BEGIN ORIGINAL
BuildingSurface:Detailed,
    Inside Shelf,            !- Name
    WALL,                    !- Surface Type
    Shelf,                   !- Construction Name
    Daylit Zone,             !- Zone Name
    Surface,                 !- Outside Boundary Condition
    Inside Shelf,            !- Outside Boundary Condition Object
    NoSun,                   !- Sun Exposure
    NoWind,                  !- Wind Exposure
    0.0,                     !- View Factor to Ground
    4,                       !- Number of Vertices
    1.0,                     !- Vertex 1 X-coordinate {m}
    0.0,                     !- Vertex 1 Y-coordinate {m}
    2.0,                     !- Vertex 1 Z-coordinate {m}
    4.0,                     !- Vertex 2 X-coordinate {m}
    0.0,                     !- Vertex 2 Y-coordinate {m}
    2.0,                     !- Vertex 2 Z-coordinate {m}
    4.0,                     !- Vertex 3 X-coordinate {m}
    1.0,                     !- Vertex 3 Y-coordinate {m}
    2.0,                     !- Vertex 3 Z-coordinate {m}
    1.0,                     !- Vertex 4 X-coordinate {m}
    1.0,                     !- Vertex 4 Y-coordinate {m}
    2.0;                     !- Vertex 4 Z-coordinate {m}
END ORIGINAL

BEGIN MODIFIED
BuildingSurface:Detailed,
    Inside Shelf Top,        !- Name
    Wall,                    !- Surface Type
    Shelf,                   !- Construction Name
    Daylit Zone,             !- Zone Name
    Surface,                 !- Outside Boundary Condition
    Inside Shelf Bottom,     !- Outside Boundary Condition Object
    NoSun,                   !- Sun Exposure
    NoWind,                  !- Wind Exposure
    0.0,                     !- View Factor to Ground
    4,                       !- Number of Vertices
    1.0,                     !- Vertex 1 X-coordinate {m}
    0.0,                     !- Vertex 1 Y-coordinate {m}
    2.0,                     !- Vertex 1 Z-coordinate {m}
    4.0,                     !- Vertex 2 X-coordinate {m}
    0.0,                     !- Vertex 2 Y-coordinate {m}
    2.0,                     !- Vertex 2 Z-coordinate {m}
    4.0,                     !- Vertex 3 X-coordinate {m}
    1.0,                     !- Vertex 3 Y-coordinate {m}
    2.0,                     !- Vertex 3 Z-coordinate {m}
    1.0,                     !- Vertex 4 X-coordinate {m}
    1.0,                     !- Vertex 4 Y-coordinate {m}
    2.0;                     !- Vertex 4 Z-coordinate {m}

BuildingSurface:Detailed,
    Inside Shelf Bottom,     !- Name
    Wall,                    !- Surface Type
    Shelf,                   !- Construction Name
    Daylit Zone,             !- Zone Name
    Surface,                 !- Outside Boundary Condition
    Inside Shelf Top,        !- Outside Boundary Condition Object
    NoSun,                   !- Sun Exposure
    NoWind,                  !- Wind Exposure
    0.0,                     !- View Factor to Ground
    4,                       !- Number of Vertices
    1.0,                     !- Vertex 1 X-coordinate {m}
    0.0,                     !- Vertex 1 Y-coordinate {m}
    2.0,                     !- Vertex 1 Z-coordinate {m}
    1.0,                     !- Vertex 2 X-coordinate {m}
    1.0,                     !- Vertex 2 Y-coordinate {m}
    2.0,                     !- Vertex 2 Z-coordinate {m}
    4.0,                     !- Vertex 3 X-coordinate {m}
    1.0,                     !- Vertex 3 Y-coordinate {m}
    2.0,                     !- Vertex 3 Z-coordinate {m}
    4.0,                     !- Vertex 4 X-coordinate {m}
    0.0,                     !- Vertex 4 Y-coordinate {m}
    2.0;                     !- Vertex 4 Z-coordinate {m}
END MODIFIED

I removed the inside shelf from the DaylightingDevice:Shelf

BEGIN ORIGINAL
DaylightingDevice:Shelf,
    Shelf,                   !- Name
    Daylit Upper Window,     !- Window Name
    Inside Shelf,            !- Inside Shelf Name
    Outside Shelf,           !- Outside Shelf Name
    Shelf;                   !- Outside Shelf Construction Name
END ORIGINAL

BEGIN MODIFIED
DaylightingDevice:Shelf,
    Shelf,                   !- Name
    Daylit Upper Window,     !- Window Name
    ,                        !- Inside Shelf Name
    Outside Shelf,           !- Outside Shelf Name
    Shelf;                   !- Outside Shelf Construction Name
END MODIFIED

These changes got rid of my Zone="DAYLIT ZONE" is not fully enclosed Warning, while only making these two warnings.

**Warning** GetSurfaceData: CAUTION -- Interzone surfaces are usually in different zones
**  ~~~  ** Surface=INSIDE SHELF TOP, Zone=DAYLIT ZONE
**  ~~~  ** Surface=INSIDE SHELF BOTTOM, Zone=DAYLIT ZONE
**Warning** GetSurfaceData: InterZone Surface Azimuths do not match as expected.
**  ~~~  **   Azimuth=90 ...
(more)
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Comments

@JasonGlazer Do you know if the inner light shelf will reflect light into the space correctly, or at least pretty well? I don't know nearly enough about EnergyPlus' modelling of lighting to say.

mldichter gravatar imagemldichter ( 2019-05-09 20:23:20 -0500 )edit

@mldichter I'm not sure. I presume it should work but I've have implemented some measures with inner light shelves and did not see the amount of impact that I expected.

JasonGlazer gravatar imageJasonGlazer ( 2019-05-15 07:15:27 -0500 )edit

@JasonGlazer Good enough! I'll accept my answer.

mldichter gravatar imagemldichter ( 2019-05-15 10:05:05 -0500 )edit
2

answered 2018-11-28 07:06:37 -0500

Thank you for posting the EnergyPlus GitHub issue, it sounds like you have found a bug. I would suggest that you temporarily comment out the DaylightingDevice:Shelf object and the objects referenced in the inside shelf name and outside shelf name. Rerun the file and that should tell you if the rest of the geometry is ok.

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Asked: 2018-11-27 12:25:11 -0500

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Last updated: May 09