Large commercial fenestration systemsspanning curtain walls, storefronts, and atriumsplay a vital role in building aesthetics and occupant comfort. However, expansive glazing can be a major source of heat gain and loss if not properly specified. Energy-efficient glass technologies optimize thermal performance while maintaining natural light and visibility.
Procurement and design professionals specifying glass for commercial projects must balance energy codes, occupant needs, and sustainability goals.
Key Energy-Efficient Glass Technologies
Low-Emissivity (Low-E) Coatings
Microscopically thin metal oxide layers that reflect infrared heat.
Reduce heat transfer without compromising visible light transmission.
Available in hard-coat and soft-coat types with varying performance profiles.
Double and Triple Glazing
Multiple glass panes separated by air or inert gas fills (argon, krypton).
Significantly improve insulation values (R-values).
Solar Control Glass
Tinted or coated glass that reduces solar heat gain while allowing daylight.
Helps reduce cooling loads in hot climates.
Spectrally Selective Glass
Allows visible light while blocking specific infrared wavelengths.
Enhances daylighting without heat gain.
Insulating Glass Units (IGUs)
Sealed assemblies combining Low-E coatings and gas fills.
Critical for meeting energy codes and certifications.
Performance Metrics
U-Value: Measures heat transfer; lower values indicate better insulation.
Solar Heat Gain Coefficient (SHGC): Indicates solar heat admitted; lower is better in warm climates.
Visible Light Transmittance (VLT): Percentage of visible light transmitted.
Benefits
Reduced HVAC energy consumption.
Improved occupant thermal comfort and natural lighting.
Contribution to LEED, WELL, and ENERGY STAR certifications.
Enhanced acoustic performance when combined with laminated or thick glass.
Design and Specification Tips
Consider climate and orientation for optimal glass selection.
Balance energy efficiency with daylight and aesthetic goals.
Specify tested IGUs with manufacturer warranties.
Coordinate with framing systems for thermal breaks and sealing.
Conclusion
Energy-efficient glass is pivotal in commercial fenestration, enabling large glazed areas without sacrificing thermal performance. Procurement and design teams specifying Low-E coatings, multi-pane IGUs, and solar control glass help create sustainable, comfortable, and code-compliant buildings.
