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Problem with ShopWithSimplePVT idf

asked 2018-01-05 13:02:06 -0600

mldichter gravatar image

updated 2018-01-07 08:52:17 -0600

The ShopWithSimplePVT idf file shows invalid fields for Collector # Branch with # replaced with 1,2,3,4,5. This shouldn't be the case as the fields Collect # objects all exist, but they aren't present in the drop down list to pick from. The simulation doesn't complain though.


I encountered this problem while writing a measure to automatically add PVT to a building. Everything was going smoothly until I tried adding a Branch with a SolarCollector:FlatPlate:PhotovoltaicThermal object in the Component 1 Name field using

idfObject = OpenStudio::IdfObject::load(idf_string)
object = idfObject.get
wsObject = workspace.addObject(object)

but the string for the Component 1 Name field is not successfully added because it's not in the drop down list in the IDF editor. My current workaround is to name the Shading object for the PVT panel and the PVT object the exact same string. The Shading object name is then in the drop down list of objects to add in the Component 1 Name field, the measure can successfully add the name of the PVT panel (even though the IDF editor thinks it's adding the name of a shading object), and the simulation runs without complaining about the Branch object.

Here is a link for the ShopWithSimplePVT idf file and a png showing the highlighted orange Component 1 Name fields in my google drive
https://drive.google.com/open?id=1q4S...

Edit: Using EnergyPlus 8.8.0

The IDFeditor isn't an insurmountable obstacle as I can forcibly write in the correct PVT name in the Branch object field. It's inconvenient to not have the PVT object name in the drop down menu, but easily fixed for one model. I really need to automate the process though. I'm working on a project to automate generation of building models to try and reach a zero net energy building in the most cost effective way. To do that, we're making measures that add skylights, change insulation, add PVT to a building, etc. We are also changing the percent of the roof that is windows, PVT, etc. As a consequence, we expect to have on the order of a million different simulation to run. Unfortunately, an EnergyPlus measure won't add what is considered an invalid object name to an IDF object field. Normally this is a good thing because the program makes sure I'm not using an object name that doesn't exist and makes debugging much easier. In this case though, I'm being prevented from adding an object that does exist, the PVT object name in a Branch object field.

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Comments

@mldichter Could you tag which apps you use (OS, E+...) and please state which versions.

Avi gravatar imageAvi ( 2018-01-06 02:13:16 -0600 )edit

Anyway it seems that there might be an issue in the IDFEditor which should not prevent you from adding PVT to Branch unless you insist on doing that manually in the IDFEditor. Even then you can type in the name of the collector and it will do.

Avi gravatar imageAvi ( 2018-01-06 03:15:04 -0600 )edit

@Avi I added which version of EnergyPlus I'm using.

mldichter gravatar imagemldichter ( 2018-01-06 11:10:12 -0600 )edit

@Avi I edited my post in response to your second comment. To be able to write an energyplus measure that can add the PVT object name in a Branch object field is a must for me to automate model generation.

mldichter gravatar imagemldichter ( 2018-01-06 11:24:16 -0600 )edit

@mldichter It might be me but I can't understand whether you are using OpenStudio to apply E+ measure or you do something else? And please post the error you get when you run the E+ measure

Avi gravatar imageAvi ( 2018-01-06 12:09:16 -0600 )edit

@Avi I'm using the Parametric Analysis Tool to apply an energyplus measure. Which tools I'm using is over complicating the problem though. The fundamental problem is still that the IDFeditor is not recognizing the PVT object as a valid object name for a field in the Branch object in the ShopWithSimplePVT idf file. That's the minimal working example to show the problem. Any ideas on how to fix it? I have a workaround right now, but it's a terrible kluge that will break my code if the problem is fixed.

mldichter gravatar imagemldichter ( 2018-01-06 12:17:52 -0600 )edit

@mldichter OK Than I must tell you that I am not familiar with PAT but as far as the measure if you get an error when you try to write the IDF object and you can post it I will try to help you. I am strongly encourage you to add tags for PAT and energyplus measure .

Avi gravatar imageAvi ( 2018-01-06 12:38:56 -0600 )edit

@Avi I'm confused. What do you mean by "get an error when you try to write the IDF object"? Are your referring to an error generated by the IDFeditor or an error generated by the PAT? Also, why add the PAT and energyplus measure tags? As far as I know those programs are working just as they should, as well as the simulation program for the IDF file. The fault lies in the IDF editor.

mldichter gravatar imagemldichter ( 2018-01-06 12:47:03 -0600 )edit

@mldichter when you run a measure if there is an error while running there must be some warning. If I get you right when you try that code :

idfObject = OpenStudio::IdfObject::load(idf_string)
object = idfObject.get
wsObject = workspace.addObject(object)

You don't get the expected outcome. Than there must be some warnings. If you were running under OS it would be found under the projects folder in file named out.osw

Avi gravatar imageAvi ( 2018-01-06 12:54:05 -0600 )edit

@mldichter I will put it in other words: How do you know that: "the string for the Component 1 Name field is not successfully added"

Avi gravatar imageAvi ( 2018-01-06 12:56:51 -0600 )edit

@Avi There is no error generated when running the IDF simulation on the ShopWithSimplePVT IDF file. You could say that the IDF editor is falsely reporting an invalid object name in a Branch object field. I know you're trying to help, but why the focus on everything except the IDF editor. The IDF editor is obviously not working. While I admit there may be a problem elsewhere, the most likely suspect right now is the IDF editor not recognizing a PVT object as a valid string in a Branch object field.

My question is just "Why is the Branch object field orange?" That's all I want to know.

mldichter gravatar imagemldichter ( 2018-01-06 13:04:35 -0600 )edit

@mldichter This going to be my final comment, maybe someone else can help, but it was you who wrote "The IDFeditor isn't really a problem". Your assumption that "the string for the Component 1 Name field is not successfully added" is wrong. Open the result IDF file with text editor and prof it to yourself.

Avi gravatar imageAvi ( 2018-01-06 13:11:05 -0600 )edit

@Avi You are absolutely correct about "The IDFeditor isn't really a problem". I was misleading at best. I've clarified above. Thank you. But I stand by the "the string for the Component 1 Name field is not successfully added". The energyplus measure leaves the field blank. My workaround was to name the shading object and PVT object the same.

So back to question, "Why is the Branch object field orange?"

And it's okay if you don't know, I don't either. That's why I'm here. But please don't comment if you don't know how to fix it. I'm here to alert the developers of the problem.

mldichter gravatar imagemldichter ( 2018-01-06 13:24:01 -0600 )edit

1 Answer

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answered 2018-01-08 19:45:11 -0600

There is a mistake in the Energy+.idd file. This is the incorrect block in the v8.8.0 IDD:

SolarCollector:FlatPlate:PhotovoltaicThermal,
   \memo Models hybrid photovoltaic-thermal (PVT) solar collectors that convert incident solar
   \memo energy into both electricity and useful thermal energy by heating air or water.
A1 , \field Name
   \reference-class-name validOASysEquipmentTypes
   \reference validOASysEquipmentNames
A2 , \field Surface Name
   \required-field
   \type object-list
   \object-list AllShadingAndHTSurfNames
   \reference-class-name validBranchEquipmentTypes
   \reference validBranchEquipmentNames

The last two lines are causing the PVT Surface Name to appear in the Branch Component Name drop-down list. Those lines should be moved up before the A2 field line:

SolarCollector:FlatPlate:PhotovoltaicThermal,
   \memo Models hybrid photovoltaic-thermal (PVT) solar collectors that convert incident solar
   \memo energy into both electricity and useful thermal energy by heating air or water.
A1 , \field Name
   \reference-class-name validOASysEquipmentTypes
   \reference validOASysEquipmentNames
   \reference-class-name validBranchEquipmentTypes
   \reference validBranchEquipmentNames
A2 , \field Surface Name
   \required-field
   \type object-list
   \object-list AllShadingAndHTSurfNames

If you make this change in the EnergyPlus-V8-8-0\Energy+.idd file, then IDF Editor will no longer tag the collector names as invalid and the names will be in the drop-down list.

I am not sure if OpenStudio EnergyPlus measures read this same IDD file or a separate IDD that is part of the OpenStudio install, so you may need to make this change in two places. The pending fix is here in this pull request.

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Comments

@MJWitte Thanks! That did the trick.

mldichter gravatar imagemldichter ( 2018-01-09 13:10:02 -0600 )edit

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Asked: 2018-01-05 13:02:06 -0600

Seen: 155 times

Last updated: Jan 08 '18