Closed aperture behavior with AFN

Hi all

I am facing and issue with closed aperture in my model.
I assigned some aperture as “operable” and “non operable” for the closed ones.
But when i monitored the Node volume flow rate, there were values for all the aperture even for the closed one.
I appears that in the idf file, the opening factor for the operable aperture is the value i specified but for the closed aperture it is 1 instead of 0.

You can see below some extract of the idf file

and the operable fraction specified in the model

How can i change the default value for the closed aperture?

Best regards.

Andy

Yes. Even closed windows have infiltration through them, which the EnergyPlus AFN accounts for.

To change the infiltration through the closed windows, you can change the flow_coefficient_closed and the flow_exponent_closed on the VentilationOpening object inside of a GHPython component:

Thanks @chris for your answer. The thing is that the air flow rate is higher through the closed aperture than opened one while flow_coefficient_closed is set to 0.0014. The probleme is coming from the default opening factor in the EMS part of the idf file. While all operable aperture have the value i gave to them, non operable aperture have an opening factor of 1. It is that defaut value i want to overide without manualy changing it in the idf file.
Best regards,
Andy

Ah, thank you for brining this up, @AndyKobe .

It looks like I introduced this bug 3 months ago when I was putting together the new honeybee-openstudio Python translators to replace the Ruby ones that we had been using:

The line of code that I added was correct and it was helping work around this fatal error that EnergyPlus throws if you set the SimpleOpening object up to have a zero openable area:

However, I put the line of code in the wrong place such that it was also causing the EMS program to set the window opening to 1 instead of zero (and the EMS program always overwrites whatever is specified on the SimpleOpening object).

I just pushed a change here to put the line of code in the right place:

… and I verified that it writes the correct EMS program for inoperable windows and doors:

You can get the fix on your end now with the LB Versioner and I also just updated the Food4Rhino installer with the fix since it’s a pretty substantial bug that affects any AFN model with inoperable windows.

Thanks again for reporting the issue, @AndyKobe!

Thanks @chris and all LBT team for your amazing job.
Andy

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