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Downgrade IDF 9.x to 7.x: Viewfactor calculation using Radiance eplus_adduvf.exe

asked 2020-01-17 11:58:08 -0600

rafael.alonso gravatar image

updated 2020-01-19 12:18:28 -0600

Hi all,

I´m trying to get Radiance´s tool adduvf.exe to work, as it was developed to bypass Energyplus limitation with non-convex zones for the FullInteriorExterior solar distributions. The software was meant to read the idf geometry, compute View factors, and write them back in the idf - I suppose that using the Zoneproperty:UserViewFactors:bySurfaceName.

Investigating the tool with Radiance developers here , it seems it was written for IDF 7.x versions, and does not work with IDF versions 9.X.

Does anyone know how to downgrade an IDF file from 9.x to 7.x? Or any other work around this issue?

So far it encounters an error related to the geometry syntax:

image description

There are some more details on Radiance forum.

Thanks, Rafael

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2 Answers

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answered 2020-01-20 12:00:44 -0600

I went ahead and updated the eplus_adduvf code to work with EnergyPlus 9.x. You can get the source from https://www.radiance-online.org/cgi-b...

Hopefully, this will get compiled and incorporated sooner rather than later, but I'm not in control of that process. I have notified the people in charge.

I tried it with Rafal's input file and it seems to work, now. It will no longer work with 7.x files, figuring people can use the upgrader tool in that case.

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answered 2020-01-17 13:10:12 -0600

updated 2020-01-17 13:11:46 -0600

In EnergyPlus v9.0, there was a change made to remove the "Shading Control Name" input field from the FenestrationSurface:Detailed object used to define windows. That shifts input fields "up" by one from previous versions, so the error is likely because it's trying to read an integer for "Number of Vertices", but instead it's reading a float or real value for the X-coordinate of the first vertex instead.

Below is a window defined in the EnergyPlus example file WindowTests.idf before and after v9.0:

Fenestration before v9.0

  FenestrationSurface:Detailed,
    Zn001:Wall001:Win001,    !- Name
    Window,                  !- Surface Type
    SINGLE PANE HW WINDOW,   !- Construction Name
    Zn001:Wall001,           !- Building Surface Name
    ,                        !- Outside Boundary Condition Object
    0.5000000,               !- View Factor to Ground
    ,                        !- Shading Control Name ***INPUT FIELD THAT WAS REMOVED***
    ,                        !- Frame and Divider Name
    1.0,                     !- Multiplier
    Autocalculate,           !- Number of Vertices
    0.200000,0.000000,9.900000,  !- X,Y,Z ==> Vertex 1 {m}
    0.200000,0.000000,0.1000000,  !- X,Y,Z ==> Vertex 2 {m}
    9.900000,0.000000,0.1000000,  !- X,Y,Z ==> Vertex 3 {m}
    9.900000,0.000000,9.900000;  !- X,Y,Z ==> Vertex 4 {m}

Fenestration after v9.0

  FenestrationSurface:Detailed,
    Zn001:Wall001:Win001,    !- Name
    Window,                  !- Surface Type
    SINGLE PANE HW WINDOW,   !- Construction Name
    Zn001:Wall001,           !- Building Surface Name
    ,                        !- Outside Boundary Condition Object
    0.5000000,               !- View Factor to Ground
    ,                        !- Frame and Divider Name
    1.0,                     !- Multiplier
    Autocalculate,           !- Number of Vertices
    0.200000,0.000000,9.900000,  !- X,Y,Z ==> Vertex 1 {m}
    0.200000,0.000000,0.1000000,  !- X,Y,Z ==> Vertex 2 {m}
    9.900000,0.000000,0.1000000,  !- X,Y,Z ==> Vertex 3 {m}
    9.900000,0.000000,9.900000;  !- X,Y,Z ==> Vertex 4 {m}

If this adduvf.exe tool in Radiance can read the EnergyPlus version for the IDF it's reading geometry from, then you can include an if/else check to alter the input field numbers accordingly ("Number of Vertices" is input #10 before v9.0 and input #9 after v9.0, e.g.). That seems much easier than figuring out a way to "downgrade" an IDF to an older version of EnergyPlus. I'm not aware of tools that can do that for you.

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Comments

1

That seems the easiest way, thank you for the detailed reply. I'll check with the developers of adduvf.exe if this can be implemented.

Thanks!

rafael.alonso gravatar image rafael.alonso  ( 2020-01-19 06:19:11 -0600 )edit
1

Developer here. This is really helpful -- thanks! What else has changed affecting the following IDF object types?

ZoneProperty:UserViewFactors:bySurfaceName

FenestrationSurface:Detailed

BuildingSurface:Detailed

Floor:Detailed

RoofCeiling:Detailed

Wall:Detailed

With this information, I should be able to update eplus_adduvf.

Cheers!

GregWard gravatar image GregWard  ( 2020-01-19 10:15:04 -0600 )edit
1

The easiest way to tell if there is a difference in input field order between specific objects is to:

  • Install both versions of EnergyPlus so that you get the Energy+.idd file (aka IDD file) for each
  • Use WinMerge or similar text compare/diff tool to search for where rules of each IDF object are set and see if differences occur

You can access installers for EnergyPlus pre-v8.2 here. It would likely be easier to share differences/workflows via email with screenshots, I'll send @GregWard an email soon.

Aaron Boranian gravatar image Aaron Boranian  ( 2020-01-19 11:06:57 -0600 )edit
1

Thanks for sending me the IDD files in an e-mail, this is probably all I need.

GregWard gravatar image GregWard  ( 2020-01-19 13:16:06 -0600 )edit
1

Hi Aaron, Greg, many thanks for the interest you´ve taken in this issue and the thorough follow up. If there is something I can assist with, I´m more than happy to do so.

rafael.alonso gravatar image rafael.alonso  ( 2020-01-20 03:42:02 -0600 )edit

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Asked: 2020-01-17 11:58:08 -0600

Seen: 173 times

Last updated: Jan 20 '20