Algorithm and assumptions for frame and total system SHGC calculations using WINDOW 7.8

[sindhu0...@gmail.com]

Hi Team,

 

I am struggling to find documentation for algorithm and assumptions for frame and total system SHGC calculations using WINDOW 7.8.

 

For the same THERM files, frame solar absorptance values, assumptions for projected frame lengths and wetted lengths,  there seem to be very high discrepancies in results between WINDOW 7.8 and those based on a spreadsheet tool using the below NFRC 200-2014 equation:

 

• Could you please confirm the formulae and assumptions used by WINDOW to calculate frame SHGC specifically the hout value used by WINDOW. Is the hout value fixed or can it be edited?
  • I found the following link suggesting a much lower convection coefficient: https://github.com/LBNL-ETA/Windows-CalcEngine/issues/77
• Is there a way to view the frame SHGC values calculated by WINDOW.

 

Your quick response will be much appreciated.

 

Kind Regards,

Sindhu