Low-E Coating
A microscopically thin metallic coating applied to glass that reflects infrared heat while allowing visible light to pass through.
Low-emissivity (Low-E) coatings are applied to one or more surfaces of an IGU to control solar heat gain and reduce heat loss. In Canadian climates, Low-E coatings are typically applied to Surface 2 (inner face of the outer pane) or Surface 3 (outer face of the inner pane) depending on the desired balance of solar heat gain and insulation.
Common products include Cardinal LoE-180, LoE-272, and LoE-366, each with different solar heat gain coefficients (SHGC) and U-values. The number after "Surface" refers to the glass surfaces counted from the exterior.