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Error after importing EnergyPlus Example IDF into OSM

asked 2023-11-28 11:32:48 -0500

Todd K.'s avatar

updated 2023-11-29 10:53:19 -0500

Update! I found a different approach that seems to work. After searching "OpenStudio example files", I came across this...

After loading the suggested measure and running it, I now have an OSM model that compiles for a DOE reference building MidRiseApt in Chicago. I am still interested in hearing comments on why my initial approach failed.


Hi. I am new to EnergyPlus and OpenStudio. I am using it to determine heating and cooling load profiles of various building types. A while ago, I found the Reference Commercial building type 8760 load profiles put out by DOE/NREL i.e. "RefBldgMidriseApartmentNew2004_v1.3_7.1_5A_USA_IL_CHICAGO-OHARE,csv". I want to recreate this (verify) using the similarly named ExampleFiles IDF file in EnergyPlus i.e. "RefBldgMidriseApartmentNew2004_Chicago.idf"

Simulating this within EnergyPlus yields some information i.e. equipment capacity but annual loads show as zero and there is no 8760 profile. So I moved on to OpenStudio. The IDF imports with some warnings about not everything being imported (probably key to this problem) and simulation stops with this error file:

*Program Version,EnergyPlus, Version 23.1.0-87ed9199d4, YMD=2023.11.28 10:33,
** Severe  ** <root>[AirTerminal:SingleDuct:ConstantVolume:NoReheat][G N1 Apartment Direct Air] - Missing required property 'air_inlet_node_name'.
** Severe  ** <root>[AirTerminal:SingleDuct:ConstantVolume:NoReheat][G N1 Apartment Direct Air] - Missing required property 'air_outlet_node_name'.
** Severe  ** <root>[ZoneHVAC:AirDistributionUnit][ADU G N1 Apartment Direct Air] - Missing required property 'air_distribution_unit_outlet_node_name'.
**  Fatal  ** Errors occurred on processing input file. Preceding condition(s) cause termination.
...Summary of Errors that led to program termination:
..... Reference severe error count=3
..... Last severe error=<root>[ZoneHVAC:AirDistributionUnit][ADU G N1 Apartment Direct Air] - Missing required property 'air_distribution_unit_outlet_node_name'.
************* Warning:  Node connection errors not checked - most system input has not been read (see previous warning).
************* Fatal error -- final processing.  Program exited before simulations began.  See previous error messages.
************* EnergyPlus Warmup Error Summary. During Warmup: 0 Warning; 0 Severe Errors.
************* EnergyPlus Sizing Error Summary. During Sizing: 0 Warning; 0 Severe Errors.
************* EnergyPlus Terminated--Fatal Error Detected. 0 Warning; 3 Severe Errors; Elapsed Time=00hr 00min  0.19sec*

I have learned a lot about the workings of EP and OS chasing down the solution with IDF Editor and other tools, but I am stumped. If someone can recreate what I did (with the example idf), I would appreciate that.


Todd K.

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answered 2023-11-29 12:36:40 -0500

updated 2023-11-29 12:37:58 -0500

@Todd K., your hunch is correct (i.e. "imports with some warnings about not everything being imported (probably key to this problem)". What OpenStudio does forward-translate to EnergyPlus, it does very well. Yet not so much when it comes to HVAC/plant when reverse-translating an IDF. From IDF to OSM, one is going from a finer (lower-level) model to a slightly more abstract (higher-level) one; information will undoubtedly be lost in translation. You'll find UMH posts on this, like this one. And a note in the SDK documentation (last paragraph).

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Asked: 2023-11-28 11:32:48 -0500

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Last updated: Nov 29 '23