Group control in WindowShadingControl with OnIfHighSolarOnWindow
Hi all,
I'm trying to control a group of shading devices collectively based on the solar radiation received at just one specific window (without using the EMS).
I listed a few fenestration surfaces in the WindowShadingControl object, selecting Multiple Surface Control Type = Group and activation based on incident solar radiation on the window (OnIfHighSolarOnWindow).
My assumption was that the shading status for all listed fenestration surfaces should be determined based on the solar radiation received by a single "reference" surface, likely the first one listed in the control object.
However, the shading devices within the same group are not always active at the same time, and it seems that each device is actually being deployed based on the solar radiation it receives individually. Here I quickly displayed the windows in the same group and the number of hours each shading device was active.
The EnergyPlus documentation doesn't clearly explain how the group control works.. it only mentions that the list of surfaces is controlled simultaneously, but it’s unclear how the triggering condition is evaluated across the group.
Do you know how this should work and whether it's possible to achieve what I am trying to do?
Tested the US Prototype Warehouse. Its corner office zone has 4 windows: 2 front ones + 2 side ones. Modified so all 4 windows reference the same WindowMaterial:Blind (InteriorBlind type). Tallied Surface Shading Device Is On Time Fraction, monthly.
First grouped all 4 windows under a single WindowShading:Control, then separately grouped front vs side windows (2x controls, same OnIfHighSolarOnWindow criteria at 100 W/m2)), switching from Sequential to Group. Same results in all cases: front windows remain in sync, side ones remain in sync. So I guess I concur ...
That said, I see consistent results (over the months) between front vs side windows (i.e. different surface azimuths). I don't see radical differences as in your case: ~430 hours vs ~1410 hours. Same window orientation, yet same shading controls?
Thanks for the confirmation. In my case, the large difference in shading hours is due to surrounding context (not shown in the image) which significantly shades the lower windows. So the individual results made sense if each window was being evaluated separately, rather than through group logic.