Detailed Berkeley Lab WINDOW Output

Last Updated: 
Friday, September 1, 2017

Software/Versions Affected:

Berkeley Lab WINDOW produces an output file with details of input and output to the calculation algorithms. It can be used to determine various values of interest. This file is called W5DEBUG.DAT, and can be generated as follows:

  • Start W5, go to File, Preferences
  • Check the "Debug Output" box
  • Click OK.
  • When you now perform a calculation on a Berkeley Lab WINDOW, the program will save the debug information in a file called w5debug.dat. Every calculation that is performed gets appended to the end of the file.
  • Perform a calculation on the window or glazing system that you are interested in. Close the program, and use the Microsoft Search program to find the file (Start, Search). It is a little unpredictable where this file gets written. It was meant as an internal debug aid, so it is not very user friendly.
  • open the file w5debug.dat using Notepad or any other editor.
  • There are 2 sections written to the file for every calculation. One for the U-value (ie winter) conditions and one for the SHGC (ie summer) conditions. You are probably only interested in the U-value section. Each section starts with
  • "Calling WINASH:" which lists the parameters that are send to the calculation routine. and then there is a part titled "Returning from WINASH:". This is what you are interested in.

Here are some values which may be of interest:



"h" stands for film coefficient in W/m2K

"con" stands for convection

"rad" stands for radiation

"in" is interior (room side)

"out" is exterior (outside)

"hin" is the total interior film coefficient

"hout" is the total outside film coefficient

This feature is somewhat buggy, so the next time you start W5, the "Debug Output" check box will still be checked (under Preferences), but the program doesn't produce the debug file (it forgot that it is checked). To reset the Debug checkbox, uncheck the box, close the program, start the program again, and check the box. Now the program will created debug output again for that session of the program. The file keeps growing, because every calculation is added to the end. It might be good to delete or rename the file after you've extracted information, so that the file doesn't grow to large. The best way to look at it, is to always go to the end of the w5debug.dat file and start looking up.