Understanding the Properties of Architectural Glass
Glass is a wonderful material that has many different properties and uses. Apart from its aesthetic features, glass is a versatile construction material with distinct properties, types, and application options. Understanding the properties of architectural glass is important in choosing the right type of glass for your window or door application.
Properties of glass
1. Transparency / Translucency
Glass is a transparent material which means it lets light pass through it and allows a clear view of the objects on the other side. It creates a visual connection with the outside world. Clear glass can also be made opaque, creating a translucency to control the amount of light that is transmitted through.
Glass is a good insulator against visible light transmission, heat, electricity, and electromagnetic radiation. Certain types of glass have high resistance against ultra-violet, infrared, and x-ray transmission. Glass is also a good sound insulator with the right thickness and spacing of panes, glass resists sound transmissions.
Glass has great strength as it can withstand the backlash of rain, sun, and wind, yet at the same time, glass has low impact resistance, cracking or shattering easily upon impact. Certain types of glass, such as tempered glass or heat-strengthened glass, are manufactured to create high-impact resistance values.
4. Chemical Resistance and Fire Resistance
Glass is highly resistant to chemical reactions can withstand the effect of the chemical reaction under different environmental conditions or acidic effects. In the case of fire, heat-treated glasses can stop the spread of flames into adjoining spaces, significantly blocking smoke and toxic gases burning furniture and materials.
Glass as a material is 100% recyclable. It does not degrade during the recycling process and can be recycled again and again without loss of quality or purity. Recycled glass helps conserve energy by reducing emissions and consumption of raw materials.
6. Color and shape
It can be blown, drawn, and pressed into any color, shape, and variety depending upon its use, dimensional requirements, and safety requirement.
Types of glass used in buildings
It is possible to change some of the properties of glass for specific purposes by changing the strength and performance qualities. And before the glass can be used as a building material it is often heat-treated for durability and safety.
1. Annealed Glass
Annealed glass is the most common type of architectural glass. It has outstanding surface quality because it does not undergo heat treatment and therefore is not subject to distortion produced by heating or tempering the glass. However, annealed glass dangerously breaks into sharp shards.
2. Tempered Glass
Tempered glass is heated to approximately 1200°F, followed by rapid cooling under a sharp airflow. This process creates a higher surface and/or edge compression in the glass and enhances the glass strength, flexibility, and mechanical resistance. This process makes the glass four to five times stronger and safer than annealed or untreated glass. Fully-tempered glass is often used where safety is a concern, because of its break pattern or when significant additional strength is needed to resist wind pressure or thermal stress.
3. Heat-Strengthened Glass
With heat-strengthened glass, the cooling process is slower, which results in lower compression strength. Heat-strengthened glass is approximately twice as strong as annealed, or untreated, glass. The heat treatment results in some levels of distortion and instances of breakage would produce large shards.
4. Laminated Glass
Laminated glass is made of two or more panes of heat-strengthened or tempered glass with a thin polymer interlayer between the glass layers. The interlayer, made through heat and pressure, keeps the layers of glass bonded even when broken. Instead of shattering on impact, it is held together by the interlayer which reduces the safety hazard from the shattered glass fragments. Laminated glass also offers other benefits, such as coloring, sound dampening, resistance to fire, ultraviolet filtering, and other technologies that can be embedded in or with the interlayer.
5. Insulating Glass
Insulated glass is composed of two or more panes of glass, separated by a spacer, filled with air or noble gases, and hermetically sealed. The combination of two panels of glasses and the trapped air is what makes insulated glass a superior energy-efficient method of glazing. Insulating glass is designed to prevent heat transfer to and out of the building, reducing heat gain and loss to provide enhanced thermal performance.
6. Coated Glass
Surface coatings can be applied to glass to modify its appearance and influence or improve properties, such as low maintenance, special reflection/transmission/absorption properties, scratch resistance, and corrosion resistance. For example, low-E coatings reduce the amount of ultraviolet and infrared light that can pass through glass without compromising the amount of visible light that is transmitted.
With its visual appeal, versatility, and capability to harness natural light better than any other material, glass is an essential component in modern age building. Constant innovations and technological advancements continue to increase the possibilities for the use of glass in the world of architecture and engineering.
Carefully selected components can influence the thermal performance of not only the window but also the entire building. To learn more about how aluminum window, door, curtainwall, and storefront systems, contact our window experts today.