Mismatch Openstudio VS Honeybee Energy+

Hi @chris and everyone,

I have a question about the difference in EUI (kWh/m2) results. For some reason, both heating and cooling EUI are very different in both simulations. Does someone know what might have caused this issue or experienced something similar?

question_energyplus_openstudio_differences.gh (113.0 KB)

Hi @BcBod ,

You have definitely found a strange issue here and I can say with certainty that it is related to the use of the HB Blend ProgramTypes component. When I just disconnect that, everything seems to come back into agreement again:

When the “Blend” component is used, I can see that something looks to be corrupted inside the OSM written by the OpenStudio component where none of the lighting/equipment definitions are coming through correctly. Maybe I just need a check inside this “Blend” component that just returns the input if you only connect one Program to it with a ratio of 1.

Wow, what a deep and subtle bug.

So I don’t think it’s really related to the “Blend Programs” component in particular but it’s because you named your Model/Building and your blended Program the exact same thing. You just called them both “housing” and this seems to have broken something very deep and subtle in OpenStudio. Maybe I can report this to NREL as a bug in OpenStudio or maybe I can do some other workaround for it to prevent it from happening again.

But, long story short, just name your objects better. Honestly, no name at all would have been much better than something as generic as “housing”.

I added a check/workaround for it here to make sure that this does not happen again:

I should probably also report it to NREL but I can’t really blame it all on the OpenStudio SDK. Just be better about naming things uniquely in the future. Connecting no name at all is really much better than connecting something generic.

Hi @chris!

Thank you so much for helping me with this issue! I would never have discovered this problem myself. Then I’ll leave the naming out or at least change the names. Amazing :slight_smile:

Thanks @BcBod ,

I reported the issue to NREL so that they can hopefully investigate and find a more permanent fix than my current workaround:

Thank you!

For some reason after adjusting the naming, most of the script seemed to work. Only now the OpenStudio simulation fails to collect data on Tab Water. Before this seemed to work, so I cannot compare the EUI outcomes of the Tab Water values. Do you know what might be the problem?

question_energyplus_openstudio_differences.gh (169.7 KB)

I’ve experimented with the HB hot water component to see if changing the settings impacts the EUI value of ±30. But for some reason, it remains the same. This seems to be related to the problem with the OpenStudio analysis.

You should probably open a separate issue for other questions that you have, @BcBod . I don’t know what you want me to look at in the Grasshopper file that you posted there. All of the service hot water results make sense to me.


The issue we discussed of different OpenStudio vs Energy+ results was solved in my simplified model with only one housing unit.

However, now that I’m scaling up the model to all the geometries needed, I get the same big differences in results again. But specifically for cooling…

Since the model is quite big I am experimenting with plugging in the geometries one by one, and this is sufficient to see the occuring problem
Draft_07_24.gh (608.5 KB)