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NFRC Approves LBNL WINDOW 7.8.55 and THERM 7.8.55 for Immediate Use

The National Fenestration Rating Council (NFRC) Board has approved Lawrence Berkeley National Lab (LBNL) WINDOW 7.8.55 and THERM 7.8.55 for immediate use.

WINDOW 7.8 / THERM 7.8 has been extensively tested by multiple simulation laboratories. In the process, numerous bug fixes and enhancements were implemented, and the software is now ready for full implementation. 

WINDOW 7.8.55 / THERM 7.8.55 may be used beginning on October 1, 2022. Beginning April 1, 2023, WINDOW 7.8.55 / THERM 7.8.55 shall be the only approved software for NFRC 700 ratings for new certifications, recertifications, or revisions/addendums. WINDOW 7.4 / THERM 7.4 and WINDOW 7.7 / THERM 7.7 shall no longer be used after March 31, 2023. Blinds in the up and stacked position, which do not require use of the CGBD may be rated using either WINDOW 7.4 / THERM 7.4 or WINDOW 7.7 / THERM 7.7 until the sunset date.

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