Hey @MichaelDonn ,
Sorry that this thread just seemed to go in a bunch of different places and we got pretty far from the original concern.
I opened your sample model from the top of this post and you are absolutely right that there’s some kind of bug in EnerbyPlus or change in the behavior of the EnergyPlus output for Zone Ventilation Total Heat Loss Energy.
It’s very clearly under-reporting the ventilation losses and I know this because, if I switch to using the AirflowNetwork for natural ventilation and using those corresponding outputs, I can get a much more balanced chart:
Let me see if I can find a solution on our end but this may be a bug in the EnergyPlus output that we’ll ultimately have to report to NREL.