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negative zone volume and Total wall area by ASHRAE 90.1 definition

Hi,

I have two warning :

1. one of my zone become negative, how to solve this? * Warning * Indicated Zone Volume <= 0.0 for Zone=ATAP TAMBAHAN

2. Total wall area by ASHRAE 90.1 not same with user entered Wall class surfaces * Warning * WriteVeriSumTable: InputVerificationsAndResultsSummary: Wall area based on [>=60,<=120] degrees (tilt) as walls * ~~~ * differs ~8.9% from user entered Wall class surfaces. Degree calculation based on ASHRAE 90.1 wall definitions.

thank you very much regards, Budijanto Chandra

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Zone "Atap tambahan" is indeed fully enclosed, yet its Wall and sloped Roof surfaces all have inverted vertex sequences: they're defined clockwise (when looking at them from outside the zone), e.g.:

BuildingSurface:Detailed,
F4A4D5,                  !- Name
Wall,                    !- Surface Type
Exterior Wall,           !- Construction Name
Atap tambahan,           !- Zone Name
Outdoors,                !- Outside Boundary Condition
,                        !- Outside Boundary Condition Object
SunExposed,              !- Sun Exposure
WindExposed,             !- Wind Exposure
,                        !- View Factor to Ground
3,                       !- Number of Vertices
8.656687477963,          !- Vertex 1 X-coordinate {m}
9.879976463316,          !- Vertex 1 Y-coordinate {m}
4.600000000000,          !- Vertex 1 Z-coordinate {m}
6.456687477963,          !- Vertex 2 X-coordinate {m}
9.879976463316,          !- Vertex 2 Y-coordinate {m}
3.400000000000,          !- Vertex 2 Z-coordinate {m}
6.456687477963,          !- Vertex 3 X-coordinate {m}
12.229976463316,         !- Vertex 3 Y-coordinate {m}
3.400000000000;          !- Vertex 3 Z-coordinate {m}


... they should be counter-clockwise, given the IDF's geometry rules:

GlobalGeometryRules,
UpperLeftCorner,         !- Starting Vertex Position
Counterclockwise,        !- Vertex Entry Direction
Relative;                !- Coordinate System


Incidentally, the 2x sloped Roof surfaces (like "F4A4D5" above) are labelled as Walls. That likely triggers the 90.1 surface tilt warning.

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Great Denis, You always have a great solution, and you are correct.

After I changed F4A4D5 to the roof, it also solved the negative zone problem.

Thank you very much Regards, Budijanto Chandra

( 2023-04-28 09:17:20 -0500 )edit