Window film technology
Emissivity
Emissivity is the ability of a surface to radiate absorbed heat; low-emissivity (low-e) films re-radiate less heat into the cabin, improving overall thermal performance.
When a window film absorbs solar energy, that energy has to go somewhere — either reflected back outward or re-radiated as heat. Low-emissivity coatings minimise the re-radiation into the cabin (or building interior).
Low-e is more critical in architectural applications, where double or triple glazing benefits significantly from a low-e coating on the inboard surface. In automotive applications, single-pane glass means emissivity matters less, but it still contributes to overall solar heat rejection performance.
For Singapore office and residential glazing, low-e architectural film can reduce aircon load by 20–30% on west-facing facades.