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ANSI/NFRC 203-2026 Procedure for determining visible transmittance of tubular daylighting devices

Publication Year

2026

Document Status

Current

Abstract

Test method for measuring the visible transmittance (VT) of tubular daylighting devices and determining the annual visible transmittance rating according to a prescribed weighted-average method.

Document History

Supersedes ANSI/NFRC 203-2023.

Publisher Information

National Fenestration Rating Council

An independent US non-profit organization that establishes objective window, door, and skylight energy performance ratings to help compare products.