Environmental Conditions — NFRC summer gives wrong glass temperature results

Last Updated:

Tuesday, September 5, 2017

Software/Versions Affected:

WINDOW›6

The default Berkeley Lab WINDOW 6 database, shipped until 3/26/2014, has solar gain for the NFRC Summer Environmental Conditions record for the U-factor Outside tab. One result of this problem is that the glass surface temperatures for the U-factor calculations will be incorrect. This can be seen in the Glazing System Temperature Data results tab, because the U-factor and SHGC temperatures will be identical, which they should not be.

If you want to use the NFRC Summer Environmental Conditions and have an older database, you can download this small Berkeley Lab WINDOW 6 database that just has the default environmental conditions in it. You can open the Environmental Conditions Library in Detailed View in your old database, click the Import button, and import the NFRC Summer Environmental Conditions record to overwrite the old incorrect record. Then recalculate your results using that corrected environmental condition, and you should see a more realistic set of temperatures, as shown below.