Infrared rejection and total solar energy rejected are different measurements, and a high IR number is not the same as total heat rejection. Here is what each specification on a data sheet actually proves — and what it does not.
Infrared rejection describes performance against a portion of the solar spectrum. Total solar energy rejected (TSER) describes the share of total solar energy — ultraviolet, visible and infrared combined — rejected by the glass-and-film assembly.
TSER is the figure to compare when the question is how much solar heat a film keeps out. Quotes leading with different metrics are not being compared on the same basis.
Visible light transmission (VLT) is the share of visible light passing through. TSER is the broadest single heat figure. Infrared rejection covers infrared wavelengths only, and test ranges and methods can differ between published figures.
Glare reduction describes the reduction in transmitted visible light versus untreated glass; UV rejection relates to fade risk rather than heat; visible reflectance describes appearance; and SHGC describes the fraction of solar heat admitted by the assembly.
3M's official Prestige Series page states up to 97% infrared rejection and up to 60% total solar heat rejection. Those figures are not contradictory: they do not share the same denominator or test scope.
The infrared figure measures performance against infrared wavelengths. The total solar figure covers the whole spectrum, including the visible light a clear-looking film is deliberately transmitting — which is the trade-off behind a film designed to keep a natural view.
A bright coastal home wanting an unchanged view prioritises high VLT and low exterior reflectance. A glare-heavy office prioritises glare reduction and shade selection. A storefront prioritises reflectance and consistency across the elevation.
A Low-E retrofit prioritises glass compatibility review before any performance discussion — the product has to suit the glass first.
Which exact product and series are you quoting? What glass condition are the published figures based on? Are you giving me TSER or infrared rejection? Can I see the current manufacturer data sheet?
A proposal naming one product for every opening on a building deserves a follow-up question too.
No. Infrared rejection measures performance against infrared wavelengths only. Total solar energy rejected (TSER) measures the share of total solar energy — ultraviolet, visible and infrared together — rejected by the glass-and-film assembly. TSER is the broader and more meaningful heat comparison.
Because the two percentages have different denominators and different test scopes. 3M's official Prestige Series page states up to 97% infrared rejection and up to 60% total solar heat rejection. The IR figure covers infrared wavelengths; the TSER figure covers the whole solar spectrum, including the visible light a clear-looking film is intentionally transmitting.
Visible light transmission — the percentage of visible light that passes through the glass-and-film assembly. A 70% VLT film looks close to clear glass; a 15% VLT film is visibly dark. It is the specification that most determines how a room feels and how the window looks from outside.
There isn't one. A film with the highest TSER may be darker than you want, and one with the highest VLT may not solve a heat complaint. The right specification balances heat, glare, appearance and glass compatibility for that particular opening and exposure.
Only carefully. Published figures are tied to a stated glass condition, and infrared rejection in particular can be measured over different wavelength ranges. Compare the same metric, on the same glass condition, from each manufacturer's current data sheet — and be cautious with any number quoted without a source.
Request a free estimate or call (302) 947-4624. Shore Tint & More (Delaware Window Film) — 3M Authorized Dealer, IWFA accredited, serving Delaware and the Maryland Eastern Shore since 1989.