ForMatter/Finishes/plate/Low-E coating (architectural glass)
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Low-E coating (architectural glass)

plate · translucent · low-emissivity, Low-E, soft-coat low-E, hard-coat low-E, spectrally selective

An invisible-thin metallic-oxide coating sputtered onto architectural glass that reflects long-wavelength infrared (heat) while passing visible light — the glass blocks radiant heat in summer, holds heat in winter, looks clear. The standard double-pane window since the 1990s. Reads as ordinary glass to the eye; performs differently than ordinary glass.

Sputtered silver-oxide stack (typically Ag-SnO₂-Ag-SnO₂ on soft-coat; SnO₂ alone on hard-coat) deposited at vacuum onto float glass during manufacturing. Soft-coat (thin silver layer): low emissivity ε ~0.04, requires inboard surface in IGU (insulated glass unit) to protect from oxidation. Hard-coat (pyrolytic SnO₂): ε ~0.15, durable / paintable but less performant. Architectural performance metrics: U-value 0.20–0.30 (W/m²·K) for double-pane low-E IGU vs. 1.0 for plain double-pane; SHGC (solar heat-gain coefficient) tunable 0.15–0.70 by stack design. Tinted variants (gray, green, bronze) tune the visible tint. Universal spec for residential / commercial new construction in temperate climates.

character — visually clear with faint cool tint at angle, performance-rather-than-aesthetic register.

Finish properties

  • leveltranslucent
  • subcategorysputtered metal-oxide on architectural glass
  • applies toglass

Incompatibilities

  • single-pane / unprotected exterior glazing for soft-coat (silver-oxide oxidizes)
  • applications requiring solar heat gain in winter — wrong SHGC for passive-solar windows

Second life

reversibilitymoderate — plating can be stripped chemically and re-plated. PVD coatings strip with NaOH or specialty chemistry; electroplated layers strip similarly.
blocks substrate recyclingno
renewabilityshop-renewable — strip-and-re-plate is the canonical path for restoring worn plating. Common services are bumper rechromers, watch-case re-platers, and PVD re-coaters (Oerlikon, IonBond).

ASTM B488 / B456 / B689 plating standards; Powder Coating Institute and industry-association literature.

Citations