Our latest window film installation on some canteen windows in Exeter to reduce the intense solar heat.
Initially this was going to be an internal window tint until we discovered the windows were laminated. With laminated glass it is generally safer to apply window film to the outside reducing the risk of breakage.
External window film performs better in rejecting heat as it is able to block the sun before it hits the glass. AV Silver 20 external window film has a visible light transmission of 16%, total solar energy rejected 82% and glare reduction of 84% along with 99% uv block. AV Silver 20 ESR10 comes with a 10 year warranty which is one of the best in the industry, most external window films only have a 5-7 year warranty.