NFRC 1C (US) (U Factor)

The NFRC 1C (US) U-Factor is a performance rating established by the National Fenestration Rating Council (NFRC) to measure the rate of heat transfer through a complete fenestration product, including glass and edge effects. For frameless glass door systems, the U-Factor indicates thermal insulation performance and energy efficiency.

Measured in BTU/hr·ft²·°F, the U-Factor reflects how effectively a glazing system limits heat loss. Lower U-Factor values indicate better thermal performance. Ratings are determined according to NFRC 100 procedures and are required for energy code compliance in accordance with IECC and ASHRAE 90.1. NFRC ratings provide standardized, third-party verified performance data used by architects, builders, engineers, and code officials.

Frameless glass door systems can achieve a wide range of U-Factor values depending on glass type and construction, from single-pane configurations to high-performance insulated glass units (IGUs) with Low-E coatings and gas fill options. NFRC-certified U-Factor ratings ensure accurate thermal performance comparisons and support energy modeling, specification documentation, and sustainability objectives.

All tests passed successfully, certification pending