Commercial Glazing Material Spec
Low-E glass coatings explained — hard-coat vs soft-coat for commercial
Low-E (low-emissivity) coatings reduce heat transfer and UV penetration on commercial glass. Two coating types: hard-coat (pyrolytic, applied during glass manufacture) and soft-coat (magnetron sputter vacuum deposition, applied to cooled glass). Soft-coat dominates commercial Florida — better performance, must be encapsulated in IGU.
Why does soft-coat dominate commercial Florida?
Soft-coat low-E (Solarban, Viracon, Guardian SunGuard) has lower emissivity (better thermal performance), lower SHGC (better solar control), and better aesthetic clarity than hard-coat. Must be on surface 2 or 3 of an insulating glass unit — cannot be exposed to weather.
Is hard-coat ever used in commercial?
Hard-coat low-E (Pilkington Energy Advantage, AGC EnergySelect) is used on single-pane commercial assemblies (rare), monolithic exterior storefronts in dry climates, and specialty applications where the coating must be on the exterior surface. Rarely the right choice for Florida commercial.
How do I spec the right coating?
Specify performance criteria (SHGC, VLT, U-factor) rather than coating type. The glazier and glass manufacturer will recommend the right coating to hit your performance target. For Florida hospitality and office: typically Solarban 70XL or Viracon VRE-67 (soft-coat) in 1" IGU.