Saving Energy: Windows & Doors

If south-facing windows are fading your furniture and turning your living spaces into a sauna, a product called reflective window film can bring back the comfort – and cut your air conditioning bills.

How it works

Sun control window films are designed to cut heat transmission through a window pane. Unlike ordinary tinted films, which block light but allow heat to pass through, reflective films have a metallic coating that bounces back up to 30 percent of the sun’s heat.

The self-adhesive film is applied directly to the window panes inside your home in a matter of minutes.

The benefits

According to manufacturers and installers, reflective window film can reduce solar heat gain by up to 33 percent – and that can have a dramatic impact on the comfort of your south-facing rooms.

And your summer electricity bills will be easier to handle as well – manufacturers say for every 100 square feet of window film you install, you’ll save one ton of air conditioning capacity!

In addition to reflecting heat, reflective window films also cut ultraviolet light that fades your furniture and reduce glare. While most homeowners choose the completely transparent version, different tint levels are also available to act as a window shade.

The window films are also made to be scratch-resistant, with most having a lifespan of more than 20 years.

The drawbacks

Applying reflective window film can increase the temperature of the glass, causes stress at the edges of the window pane. In older or poorly-built windows, this can cause the glass to crack.

To prevent this from occurring, your window film dealer will carefully analyze your windows and location, including window size, quality of construction, and indoor/outdoor temperature, to determine which type of film will work best for your home.

Almost all manufacturers offer warranties against this type of damage, so be sure to ask your dealer before you purchase.

The cost

The average cost of having reflective window film installed is about $40-60 per window, or about $5-7 per square foot.

While non-reflective tinted window film can be a do-it-yourself project, reflective sun control films should be installed by professionals to ensure maximum benefit.

rule

Are you an Alliant Energy customer?

If you’re an Alliant Energy utility customer in Iowa or Minnesota, you can earn cash back when you purchase high-efficiency EnergyStar replacement windows!

Looking for an energy-smart window dealer?

Try Alliant Energy’s online Dealer Locator to find experts in your area.

rule

Brochures and fact sheets:

Energy-Efficient Windows
By the U.S. Department of Energy [PDF format]

rule

Learn more:

Efficient Windows
This non-profit site provides unbiased information about the benefits of high-performance windows.

Solar Expectations

3M Scotchtint Sun Control Window Films