For residential applications—where a neutral glass color is usually a priority—there are a range of pyrolytic (“hard coat”) and sputter-coated (“soft coat”) product options that combine color neutrality with customized annual energy performance. Depending on where North American homes are located, the priority is either on minimizing annual heating costs by choosing a glass with passive solar properties or reducing year-round air conditioning usage by selecting a solar control product. There are a number of energy-efficiency programs that can help window makers and consumers make the best glass choice for their region, including the ENERGY STAR® program.
When specifying energy-efficient glazings for architectural applications, the following key factors should be considered: Solar heat gain coefficient (SHGC), Visible light transmission (VLT), Level of external visible light reflection (LR), and Color.
Detailed information about the building’s projected annual energy usage, desired interior temperature, and, where appropriate, the level of air conditioning in the building will determine the maximum permissible solar heat gain for any given façade (i.e. the solar energy that passes through the glazing in the form of heat). The level of light desired inside the building, the visual comfort of occupants and likelihood of glare, and the type of lighting will all help determine the correct LT level. The color and reflectivity of the facade—whether it has a transparent, matte, or mirror effect—are aesthetic choices that can be determined by the architect.
The glass performance characteristics above are all interrelated. Choosing certain values for one criterion may restrict the choices available in other areas. For example, achieving a very low SHGC—which means excellent solar heat blocking—may require choosing a tinted or slightly reflective glass. In terms of solar and light performance, in general colored or coated glasses achieve higher levels of performance.
To deliver customized performance for its customers, AGC uses two coating technologies:
- Pyrolytic or “hard” coatings, including Comfort E-PS™, Sunergy®, and Stopsol®
- Sputter or “soft” coatings, including Comfort Ti-PS™, Comfort Ti-AC™, Comfort Ti-AC 40™, Comfort Ti-AC 36™, Comfort Ti-AC 23™, and Comfort Ti-AC 28™
The design versatility and superior durability of glass make it an ideal choice for a wide range of door applications. Pattened glass can be specified in varying degrees of privacy and diffusion for use as an upscale design element in residential shower door applications. For commercial applications, fire-rated glass is available, as well as laminated glass options which can add additional safety and security.