Troubleshooting for unstable OpenStudio model?

asked 2021-06-01 21:43:09 -0500

jbatt gravatar image

I'm having an issue where I get drastically different results between runs of the same model without making any changes (or even touching/re-saving the model). I only leave the run window to view results before hitting run again. I've never encountered an issue like this and was wondering if there are any reliable troubleshooting methods.

Images showing results discrepancies below:

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Comments

Not sure if this is what you are seeing, but if you ran a simulation on Monday, and then on Tuesday you made change to the model, and then go to the results tab without re-running the simulation. You will be looking at results from the state of the model on Monday. If you now re-run the simulation and go back to the results tab you will see results of the current state of the model. If instead you are just running multiple times without any model changes and the results keep changing, then that is not expected and should be investigated. Known cases around object order result in small changes.

David Goldwasser gravatar image David Goldwasser  ( 2021-06-02 12:45:30 -0500 )edit

What version of OS/EP are you using? I experienced similar "stability" - meaning inconsistent behavior- issues with an EP v9.0. Here's a link to the closed issue for reference, which was specifically related to AirTerminalSingleDuctPIU objects (https://github.com/NREL/EnergyPlus/is...). Have you tried running the IDF outside of OS to try to isolate whether it's an OS or EP issue?.

MatthewSteen gravatar image MatthewSteen  ( 2021-06-05 22:19:38 -0500 )edit