Hi All,
Looking at the passive solar heat gain of a structure and just wondering if the warning mentioned above will have a large impact on space heating or cooling.
If you add "Output:Diagnostics,DisplayExtrawarnings" to your input file you can usually get enough information to diagnose the problem. Often the problem is just edges of surfaces that are not lined up. Generally, you should confirm if the zone volume being used in the simulation is what you expect. If it is then it is not a problem. The zone volume is only used in a few places related to airflow. Also note, the algorithm that determines if the volume is not enclosed is not full proof and sometimes shows something is wrong when it is not.
Thanks for the many responses, the program is defaulting to my my entered zone volume rather than calculated. The energy demands make sense given the values I am getting when calculated with other software.
Asked: 3 years ago
Seen: 1,081 times
Last updated: Jul 09 '21
It's hard to know, it could be trivial or could be a huge problem. You should certainly look at geometry and identify what causes this and if you can fix it. If you don't fix it you should look at the reported floor area and volume and see if it is what you expect.
If an envelope element does not exist where it should (i.e., you are missing a wall), lack of thermal mass and radiation/convection provided by that wall element to the zone air would also impact load balance. See @shorowit's reply below: leaving a gap in the enclosure does not result in infiltration. If you are using OpenStudio to generate your IDF you should look in the Geometry tab; I think there is a way to render by constructions, boundary conditions etc. (see https://www.youtube.com/watch?app=des...)
I suggest an empirical test: Enter very different values for the Zone: Volume field and see how sensitive the results are.
@sashadf1 That's not how EnergyPlus (nor DOE-2 or many other similar engines) works. A "missing" surface does not mean you have a hole in your building that brings in infiltration. You can absolutely run EnergyPlus without fully enclosed surfaces, we do it all the time.