Low-E Glass ndash The Ultimate Guide for Energy- Solutions in Modern Construction Automotive Glazing and Energy- Buildings

​​Low-Emissivity (Low-E) Glass – Technical Specifications & Application Guide​​

Low-E glass is a high-performance coated glazing product designed to control thermal energy transfer while maintaining visible light transmission. The microscopically thin metallic coating reflects infrared radiation, significantly improving a building's energy efficiency.

​​Coating Technologies Comparison​​

​​Optical Performance Data​​

1. ​​Spectral Properties:​​

   • Visible Light Transmission (VLT): 25-80%

   • Solar Heat Gain Coefficient (SHGC): 0.20-0.75

   • UV Rejection: 60-75%

   • Light-to-Solar-Gain Ratio (LSG): 1.1-2.3

2. ​​Thermal Values:​​

   • Center-of-glass U-value:

     • Single pane: 3.1-3.5 → 1.8-2.2 with Low-E

     • IGU (6mm air): 2.8 → 1.4-1.8

     • IGU (argon): 2.6 → 1.1-1.4

​​Advanced Coating Architectures​​

1. ​​Double Silver Coatings​​

   • Two Ag layers for superior performance

   • VLT 60% / SHGC 0.35 / U-value 1.0

2. ​​Triple Silver Coatings​​

   • Three Ag layers (premium product)

   • VLT 70% / SHGC 0.30 / U-value 0.9

3. ​​Hybrid Coatings​​

   • Combined Low-E + solar control

   • Spectrally selective transmission

​​Climate-Specific Recommendations​​

​​Manufacturing Standards​​

1. ​​Coating Durability:​​

   • EN 1096 (Europe)

   • ASTM E2141 (USA)

   • ISO 9227 (Salt Spray Test)

2. ​​Optical Performance:​​

   • ISO 9050 (Solar parameters)

   • NFRC 100-400 (US ratings)

3. ​​Thermal Testing:​​

   • EN 673 (U-value calculation)

   • ISO 10292 (Thermal transmittance)

​​Leading Products by Manufacturer​​

1. ​​Vitro Architectural Glass (Solarban Series)​​

   • Solarban 90: VLT 56%/SHGC 0.23

   • Solarban R100: PHI-certified (U=0.7)

2. ​​Guardian Glass (Clarity Series)​​

   • Clarity 76/50: VLT 76%/SHGC 0.50

   • Clarity Neutral 70/35: Color-neutral

3. ​​Saint-Gobain (Cool-Lite Series)​​

   • Cool-Lite ST 140: Triple silver

   • SGG Planitherm XN: Hard-coat

4. ​​AGC (EnergyNXT Series)​​

   • EnergyNXT 70/37: Double silver

   • Stopray Vision 50: High VLT

​​Installation Considerations​​

1. ​​Coating Orientation:​​

   • Soft-coat must face air gap in IGUs

   • Hard-coat can face either direction

2. ​​Edge Deletion:​​

   • 10-15mm edge removal for soft-coat

   • Critical for structural glazing

3. ​​Compatibility:​​

   • Can be combined with:

     • Lamination (for safety)

     • Tinting (for aesthetics)

     • Fritting (for shading)

​​Sustainability Impact​​

• ​​Energy Savings:​​

  • 30-50% reduction in HVAC loads

  • 5-7 year ROI in commercial buildings

• ​​Environmental Certs:​​

  • LEED v4.1 EQ Credit (Daylight)

  • BREEAM ENE 01 (Energy)

  • Cradle to Cradle Certified®

​​Performance Verification​​

1. ​​Field Testing Methods:​​

   • Infrared thermography (qualitative)

   • Spectrophotometers (quantitative)

   • U-value meters (thermal transmittance)

2. ​​Quality Control:​​

   • Batch testing of optical properties

   • Coating thickness verification (XRF)

   • Color consistency (ΔE<3)

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