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OpenStudio 1.12.0 to 1.13.0 conversion issues

asked 2016-10-11 16:34:49 -0500

ethankheil gravatar image

updated 2016-10-13 09:43:51 -0500

I am noticing a significant difference in the energy consumption (about 10% change) associated with several models before and after they are upgraded to OS 1.13.0. I have noticed that the heating and cooling loads show significant variation, which may be driving the overall differences. I also noticed that the "Gross Wall Area" values in the updated 1.13.0 model are all equal to "0.0" and am wondering if this might be a clue as to what is going on.

Any thoughts on what changes might be driving these differences? Are these differences due to planned changes within the 1.13.0 version of OS or perhaps a bug in the conversion process?

Note: no other changes were made other than the automatic upgrade initiated when using the new 1.13.0 OS GUI.

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Hey, This is interesting. I updated an older model similarly, from 1.11.0 to 1.13.0 and compared the results. There is no significant energy consumption difference (0.1% ). The Gross wall areas are showing up fine as well. Maybe this is something to do with your specific model, or the version from which you upgraded it from?

gokul gravatar imagegokul ( 2016-10-12 09:49:06 -0500 )edit

I updated these from 1.12.0 and experienced the same issue for 3 completely different models. The second model I updated had closer to a 50% increase in energy use! @gokulram , is the breakdown of your energy consumption among different end uses also within 0.1%? Or just the total energy consumption? On of my models ended up with very similar overall results before and after the upgrade, but it turned out to be a coincidental balancing from increased heating and decreased cooling that led to negligible overall energy consumption difference, but significant difference in the actual operation.

ethankheil gravatar imageethankheil ( 2016-10-12 10:07:39 -0500 )edit

@ethankheil, can you post a link to one of the models or email to OpenStudio@nrel.gov. You may also want to look at the eplusout.err file for any warnings that might indicate what is happening.

David Goldwasser gravatar imageDavid Goldwasser ( 2016-10-12 10:23:27 -0500 )edit

@ethankheil, I just checked the breakdown as well, and they are all within 1%. There is a balancing between my heating and cooling, like you mentioned, but the changes to both are within 1% in the two models.

gokul gravatar imagegokul ( 2016-10-12 11:00:38 -0500 )edit

We did move from EnergyPlus 8.5 in OpenStudio 1.12.0 to EnergyPlus 8.6 in OpenStudio 1.13.0 so that could account for very minor changes in performance. But the 0 Gross Wall Area indicates an issue somewhere in the pipeline (Either OpenStudio or E+).

David Goldwasser gravatar imageDavid Goldwasser ( 2016-10-12 11:55:34 -0500 )edit

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answered 2016-10-12 23:38:35 -0500

@ethankheil, I wasn't able to reproduce the Gross Wall Area issue on may Mac with 1.13.0 installed with your model. Below is also image of end use breakdown so you can compare it against your run.

image description

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Trying to figure out what might be different for your run. An unlikely cause is the operating system.

Another thought is to confirm that the correct version of EnergyPlus is being used. Look for any additional versions of EnergyPlus in the show tools dialog and delete versions of EnergyPlus that are not contained within OpenStudio.

image description

One last idea is to inspect the IDF to see if it looks valid and then manually run it in EnergyPlus.

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Thanks, @David Goldwasser. That's interesting. I also seem to get the same values as you for wall areas once I dig into the eplustbl.htm file. It just isn't being reflected in the OpenStudio output within the Zone Overview > Zone Summary section (how can I copy and paste images into this comment?).

In this case, maybe the "Gross Wall Area" section of the OpenStudio output is referencing the "Underground Gross Wall Area" of the EnergyPlus output instead of the "Above Ground Gross Wall Area"? In my model, all of the underground wall area fields are zero and above ground wall areas are positive.

ethankheil gravatar imageethankheil ( 2016-10-13 11:15:40 -0500 )edit

I removed the references to older versions of EnergyPlus, but still get the same output. After digging into the output, it seems like some of the overall variation might be driven by differences in sensible heat gain components between the 1.13 and 1.12 versions. In particular, the "Infiltration heat removal" and "Opaque surface conduction and other heat removal" losses are greater in the 1.13 run than the 1.12 version. Here's a summary of total energy use for different runs of the same input file:

  • OS 1.12 - 8322.34 GJ
  • OS 1.13 - 8932.34 GJ
  • EP 8.5 - 8326.02 GJ
  • EP 8.6 - 8327.71 GJ
ethankheil gravatar imageethankheil ( 2016-10-13 11:21:52 -0500 )edit

Ah, the reporting measure is looking for "Gross Wall Area" column, but it now appears that has been split into "Above Ground Gross Wall Area" and "Underground Gross Wall Area". I can fix that, and I'll follow up on the performance differences. It seems that you are getting different results between 1.12 OS which uses EP8.5 and running directly in EP8.5. Also same behavior between OS 1.13 and EP 8.6, but with much. greater difference.

Any change you can post the 1.12.0 OSM file as well?

David Goldwasser gravatar imageDavid Goldwasser ( 2016-10-13 12:42:34 -0500 )edit

I have added the 1.12.0 model to the same folder: https://drive.google.com/drive/folder...

Is there a way to run OS files in 1.12.0 for now (and forgo automatic upgrades) without uninstalling 1.13.0?

ethankheil gravatar imageethankheil ( 2016-10-14 13:51:20 -0500 )edit

Thanks for posting that file. I was able to reproduce your results and updated the issue. I got 8326GJ in 1.12.0 and then 3927GJ in 1.13.0.

We'll investigate and get back to you. To Answer the question about re-running 1.12.0 after installing 1.13.0. You can manually launch the older version of the stand alone OpenStudio application. It is Only the SketchUp Plugin that follows the most recently installed version. Thanks again for posting the 1.12.0 file.

David Goldwasser gravatar imageDavid Goldwasser ( 2016-10-14 15:14:12 -0500 )edit

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Asked: 2016-10-11 16:34:49 -0500

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Last updated: Oct 12 '16