Fire-rated glass is typically used in interior applications to protect people and property in the event of fire. It does this in two ways, by compartmentalizing the fire to prevent it from spreading to other areas and by protecting paths of egress so building occupants can safely exit the building. Recently, there has been a steady increase of fire-rated glass being used in the building envelope. Today, we see exterior fire-rated glazing going beyond punched openings and into fully engineered curtainwall systems that can perform like the rest of the building envelope.

One aspect that architects pay close attention to when it comes to specifying materials for the building envelope--fire-rated or non-fire-rated--is energy performance. The National Fenestration Rating Council (NFRC) is an independent nonprofit organization that establishes objective energy performance ratings for windows, doors, and skylights to help architects, building envelope consultants, and owners make informed decisions based on tested or certified energy performance. One of the ways it does this is through the Component Modeling Approach Software Tool (CMAST), which establishes a set of performance libraries of approved components (frames, glass, and spacer) that users can access to configure fenestration products for a project, and obtaining a U-factor, Solar Heat Gain Coefficient (SHGC), and Visible Transmittance (VT) rating for those products.

Today, architects and consultants can download approved fire-rated glass and framing components in the CMAST database to simulate the U-factor, SHGC, and VT of exterior one- and two-hour fire resistive window/wall assemblies that incorporate SAFTI FIRST’s SuperLite II-XL glass and GPX Framing with other glazing or spacer components available in the CMAST database. This allows them to design energy-efficient, NFRC certified fenestration systems that meet the most stringent fire-rated requirements.

“SAFTI FIRST is constantly striving to provide the architectural community with more tools to make the integration of fire resistive glass and framing into the overall building envelope easier,” says Tim Nass, vice president of national sales at SAFTI FIRST. “With our products being available in CMAST, designers, specifiers, and building owners are assured that every facet of their building design-meets or exceeds fire-rated code requirements, aesthetic intent, and energy performance levels established and expected for their building.”

Per the NFRC’s Frequently Asked Questions on CMA, California has approved CMA for Title 24 compliance purposes for nonresidential and residential high-rise (four habitable stories or greater) site built fenestration. Other states that reference NFRC 100 for U-Factor and NFRC 200 for SHGC and VT will benefit from using CMA to generate ratings. ASHRAE 90.1 references NFRC 100 and 200, and is referenced in a majority of states as their commercial building energy code.

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