Window film Q & A

Uses include minimizing cooling costs, cutting glare, creating privacy, reflecting heat inside and more
By Darrell Smith
Window film Q & A

Decorative films can be used to make standard glass look like frosted, etched or patterned glass in colors or in white or black matte looks. [Photo: IWFA]

What is window film? Is there more than one type?

Window film is a flexible product composed of one or more layers of coated or chemically treated polyester that can be installed on glass. It is primarily used for retrofit applications to existing windows.

There are several types of window film products. Each type is designed for a particular end use: solar-control, insulation, UV blocking, safety and security, glare control and privacy, decoration, and automotive.

Quality window films offer up to 99 percent UV protection, and solar-control films are available with different levels of insulation improvement. For exterior windows, products that offer solar control and safety/security in a single product would likely be the most beneficial. For interior windows on doors or glass partitions, decorative products or safety/security products could be used.

What are the benefits of window film?

Solar-control films can block as much as 80 percent of the solar heat coming through glass into a building, thus decreasing the heat load on the air-conditioning system and reducing energy costs. Professionally installed window film can reduce cooling costs by up to 30 percent.

Films can be darker for glare control or privacy purposes or appear almost totally clear. More than 250 solar-control films are National Fenestration Rating Council-certified, so users can be assured of the energy-performance potential of the window film.

Safety/security window film works when glass breaks, controlling the post-break behavior of the broken fragments, generally by holding the pieces together attached to the film.

Decorative films can be used to make standard glass look like frosted, etched or patterned glass in colors or in white or black matte looks, enhancing aesthetics and privacy.

Does window film prevent fading of fabrics?

It is estimated 40 to 60 percent of fade is caused by exposure to ultraviolet energy; the use of window film with its UV-blocking ability can prevent up to 99 percent of that contribution to fading. Other factors that contribute to fading are visible light and heat, so the glare reduction and energy-savings properties of window film can further reduce the rate of fading that might otherwise occur.


A trained window-film specialist, using specific tools and guidelines from a manufacturer, can determine how much added energy savings or other benefits might be achieved by adding window film to newer types of windows. [Photo: IWFA]

How is window film installed?

Although window film can be installed as a do-it-yourself product, to achieve the best results and obtain the maximum manufacturer's warranty coverage, a skilled professional window film company should install it.

How long will window film last?

Window films typically have at least a five-year manufacturer's warranty, but products today generally have 10 to 20 years of warranty coverage from the manufacturer, dependent on the specific film and intended use.

Does window film require special care?

Installed window films can be cleaned with normal non-abrasive, non-corrosive cleaning liquids and soft paper. towels just as you would clean glass. The films have a scratch-resistant surface like the scratch-resistant lenses found in many eyeglasses today.

About the Author

Darrell Smith is the executive director of the International Window Film Association, a nonprofit organization that educates about what window film can and cannot do.

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