HB Windows scheduled to always open but high aperture surface temps & different swMRT with different window material


I’m trying to model a shade textile as a HB Room with the textile as roof and walls with 95% of their surface as windows. See below:

I then use the HB Ventilation Control and HB Window Opening Components to set the apertures as always open (apertures operable option is definitely set to True). Like so:

It does make a difference to the resulting air temp and MRT inside the room but there are still big overestimations of MRT compared to my measurements. When I look at the surface temperatures of the apertures they are a lot higher than the EPW air temp, and measured temps.

I have a kind of workaround for this, with its own issues (see Error Custom HB Glass and Window material) but I’d like to understand what is happening. I.e Why the apertures are measurable if they are always open? I had assumed they ‘disappear’ in the simulation. Why the high surface temperatures if the EPW air temp and that inside the room are relatively close showing that the windows are recognised as open on some level?