Volume 39,  Issue 12,  December 2004

GANAPerspectives

Understanding Architectural Glass
    GANA Releases New Architectural Glass Guide

by Mauro DiFazio

The Glass Association of North America’s (GANA) flat glass manufacturing division (FGMD) recently published a new Specifiers Guide to Architectural Glass on its website at www.glasswebsite.com. The document is available as a free download, and is designed to provide architects, engineers and specifiers an introduction to the world of today’s architectural glass. It is the first in a series of educational resources to be provided by the FGMD. 

The Float Process
The Specifiers Guide begins with a detailed description of how today’s float glass is manufactured. From batch materials, to the ribbon of glass floating on a bath of molten tin, to the slow cooling process of manufacturing today’s glass, the technical process is described in easy to comprehend language. The chapter on the manufacturing process provides design professionals an understanding of the steady-state 24-hours-a-day, 365-days-a-year operations of the float glass manufacturing facilities, and the critical role recycling plays. 

Types of Glass
The second chapter of the guide helps design professionals carefully consider the types of glass, their performance characteristics and how these factors relate to the design, specification, building code and construction requirements for residential and commercial buildings. Detailed descriptions of annealed, heat-strengthened, fully tempered and laminated glass provide an understanding of how each product performs. A glass characteristics table in the guide provides a brief, descriptive summary of how each product performs in applications, and includes wind-load resistance, thermal stress resistance, impact resistance, breakage patterns and penetration resistance. Applicable consensus standards are referenced for each product.

Glass Strength
Physical properties and glass strength are addressed in chapter three. A table of average physical and mechanical properties of soda lime float glass includes: a modulus of elasticity, coefficient of thermal expansion, modulus of rupture, chemical composition and additional factors that are needed when considering engineering analysis and designing with glass. Information is provided regarding resources engineers may use in determining the load resistance of glass for building applications.

Performance Properties 
The final chapter provides a thorough explanation of the thermal and solar optical performance properties of float glass. Performance elements addressed include:
    • The solar spectrum;
    • Visible transmittance;
    • Solar heat gain;
    • Solar heat gain coefficients;
    • Shading coefficients;
    • Solar energy absorptance;
    • Glazing emissivity; and
    • U-factors.

Tables provide a generic performance comparison of solar heat gain coefficients and visible transmittance for a number of glass products and a U-factor comparison including the use of different glass products and coatings in insulating glass units.

Appendices to the guide provide contact information for the members of the GANA flat glass manufacturing division, a list of referenced standards and contact information for referenced organizations.

While the guide is focused on information for architects, engineers and specifiers, glass industry personnel will also find the resource of value in providing support to the design professionals and in training personnel within their own organizations. The Specifiers Guide to Architectural Glass may be downloaded free of charge from the GANA website at www.glasswebsite.com. 

the author
Mauro DiFazio is the director of sales and marketing for Visteon Corp. of Tulsa, and also serves as GANA’s flat glass manufacturing division chairperson.


USG

© Copyright Key Communications Inc. All rights reserved. No reproduction of any type without expressed written permission.