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How can I get EnergyPlus results in English (I-P) units when running OpenStudio?

asked 2014-10-24 15:33:14 -0500

Mel's avatar

updated 2017-06-04 10:17:08 -0500

When using open studio, where do I find a measure or change a setting that will give me the same Energy Plus Results in English units? Metric doesn't do me any good - I don't have time to convert all of my results. Is there a report to load that will do this or a setting I need to change? I've already changed open studio preferences to English (I-P).

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answered 2014-10-28 00:03:28 -0500

updated 2015-08-31 14:11:09 -0500

See the link and steps below to create an EnergyPlus Measure that will allow you to change the output file formats and units.

Change Output File Formats And Units Measure

  1. Copy the contents of measure.rb
  2. Create a new measure from the Measures tab in OpenStudio
  3. Name the measure in the dialog box
  4. Measure Type: EnergyPlus Measure
  5. Taxonomy: Reporting, QAQC
  6. Create measure and open for editing
  7. Open the newly created measure.rb template file
  8. Replace the template code with the code from the file above or simply replace the measure.rb file entirely.
  9. Save the measure.rb file and add it to your OSM as an always run EnergyPlus measure

The measure allows the user to select options for output file formats and unit conversions for the EnergyPlus object OutputControl:Table:Style.

After a simulation the results in IP units will be available from Results Summary > Reports > EnergyPlus Results. The output files in IP units will be available from osm directory > run > EnergyPlus-0.

Note: Using this measure will prevent OpenStudio from displaying the built-in IP reporting measure (Issue #283).

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As you noted @MatthewSteen, setting the OutputControl:Table:Style object in EnergyPlus has interactions with other parts of OpenStudio including reporting measures. Unfortunately, it is not possible to have E+ report IP units to html and SI units to the SQLite output. We have purposefully kept the OpenStudio model API in SI units and provided conversion methods for other unit systems to keep things simple. The hope was that providing reporting measures in IP units would satisfy the demand and people would not have to use the OutputControl:Table:Style workaround. Is that a valid option?

macumber's avatar macumber  ( 2015-03-08 23:02:06 -0500 )edit

Good to know @macumber. I've overlooked Reporting Measures as a way to produce output in IP units as well as other purposes such as LEED reporting. However, I do use the EnergyPlus results more than the OpenStudio results and the OutputControlTableStyle measure above is one I use on every model.

MatthewSteen's avatar MatthewSteen  ( 2015-03-09 09:02:42 -0500 )edit

For the record, the OpenStudio team had a meeting today and decided that the right way forward is to create a reporting measure that matches the eplustbl.html in content but allows for IP units. Once this measure is available we will package it with OpenStudio and remove the ability to change the unit conversion in OutputControl:Table:Style, EnergyPlus output will always be in SI units. This decision is documented in this issue.

macumber's avatar macumber  ( 2015-03-10 22:13:04 -0500 )edit

@MatthewSteen your measure link is dead

Jamie Bull's avatar Jamie Bull  ( 2015-08-31 08:49:30 -0500 )edit

Thanks @Jamie Bull, it's also no longer as relevant since there's one on the BCL. I will update above to point to my GitHub repo for those interested.

MatthewSteen's avatar MatthewSteen  ( 2015-08-31 09:13:00 -0500 )edit

answered 2015-01-01 14:38:25 -0500

MattStewart's avatar

You could also add (replace) Output command in your in.idf file.

OutputControl:Table:Style, Comma, ! Column Separator InchPound; ! Unit Conversion

Run the model as usual then look in the folder ModelToIdf for the in.idf. This is what gets sent to Energy Plus. Just add the above and you will get results cfm, kBtu, ft3, kWh. Give your in.idf file a new name and you can always look at tables in both units. Matt

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It's important to note that this won't work inside of OpenStudio (like the measure above) but will work if you run the in.idf through EnergyPlus directly.

MatthewSteen's avatar MatthewSteen  ( 2015-01-02 10:20:17 -0500 )edit

answered 2014-10-24 16:29:51 -0500

updated 2014-10-24 16:30:39 -0500

There is no user facing setting in the OpenStudio Application to change over to IP units on the output side. Your question does make me think we should respect the "units" preference in the OpenStudio Application when exporting the idf file. Currently that only impacts the input values that you see in the Application.

All is not lost. You can make an OpenStudio Measure to manipulate the idf file to give you IP. You need to look for the OutputControl:Table:Style object and edit the Unit Conversion field.

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@Kyle Benne, downstream reporting measures may depend on units being reported in SI in the output files. Our practice has been to only request results from E+ in SI units, reporting measures can export reports in any units they want. This mirrors our practice that the input file is only in SI units while application views of the model can be in IP.

macumber's avatar macumber  ( 2015-03-08 18:02:12 -0500 )edit

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Asked: 2014-10-24 15:33:14 -0500

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Last updated: Aug 31 '15