What is it?
Window film is usually retrofit to the interior side of a window, however in some scenarios a professional WFAANZ film installer will recommend an external window film, which is applied to the outside of the glass.
Suitable for commercial and residential applications, external films reject solar energy on the outer pane, keeping the inner pane cool and significantly reducing the solar energy that can penetrate the glass. Exterior films can provide up to 83% total heat rejection and 91% glare reduction (according to NFRC results, available on request).
Why Use It?
A selection of shades, VLT (the darkness of the film) and reflection levels give you design flexibilty when choosing an external film. You could opt for a reflective exterior film to change the appearance of the glass while providing high solar heat rejection and maximum privacy. A heritage listed building could apply a non-reflective exterior film to reduce heat, UV and glare, which allows natural light inside the room but does not alter the building’s appearance.
Despite being exposed to the elements, the exterior films available in Australia come with a four to fifteen year warranty. Ask your installer about edge sealing, as some exterior film manufacturers insist on this process for the install to meet warranty requirements.
When to Use It?
- If you want to apply film to low E glass, external window film will leave the Low E surface on the interior of the glass intact. This maintain its cold weather insulation while bolstering its warm/hot weather insulation.
- To avoid thermal breakage, care must be taken when matching film to tinted, laminated, tinted laminated and double glazed windows. Exterior films are more compatible with these glass types.
- When there are problems accessing the window from the inside of the building.
- Large skylights with polycarbonate or glass are suited to external films.