Everything You Need to Know About Solar Window Film

You know the feeling. It’s a scorching-hot day, and the blackout curtains aren’t doing enough to block out all that sunlight. As frustrating as it can be to regulate room temperatures throughout the home, one solution might be easier and cheaper than you think. Here’s what you need to know about solar window film and how it can bring quick and long-lasting results to your home.

What Is It, and How Does It Work?

Applied to the insides of windows, it keeps ultraviolet light away from the house interior and improves energy efficiency—all of which help control the temperature year-round. Since solar films protect from UV light and heat, they also minimize flooring and furnishings from fading colors. 

Made from multiple layers of polyester, resin, and sometimes metal, its polyester layer absorbs and reflects the sun's rays away from your home, blocking as much as 95% to 99.9% of UV radiation. According to a study in Sustainability Journal, research shows that window films can reduce annual cooling energy consumption by 35%.

Costs

The costs vary depending on the window size, window style, and film quality, but expect to pay $8 to $15 per square foot. Film for a typical sliding glass door costs $300 to $500, and film for an average double-pane window costs $100 to $150. Tinting multiple windows with solar film may cost around $300 to $900.

Choosing a Product

Knowing which type is best for your windows is key to getting the most effective use out of it. Here are a few tips for finding the right energy-efficient window film:

• Film warranty: High-quality products tend to come with a lifetime warranty, and some can last for as long as 30 years.

• Window warranties: Lifetime warranties aren’t the only thing you want to look out for. Some solar films void the window manufacturer warranty, so look for companies that pick up that warranty word-for-word.

• Heat-retaining and heat-rejecting products: Newer technology helps retain heat during the winter and rejects heat during the summer, helping you get year-round benefits.

• Tint: Some homeowners may want a clear film that doesn’t noticeably affect the natural light or tone coming into their homes. Others, however, might prefer a tinted one.

DIY Installation

Installing window film doesn’t require a professional—especially if you like a simple DIY project. The key to a successful installation is in both the preparation and application. 

Here are step-by-step instructions on how to install:

1. Clean the window surfaces to ensure they’re spotless.

2. Cut your film to about 1 inch wider and longer than the actual window size.

3. Remove the adhesive on the back (if applicable).

4. Spray your windows with either water or a mix of water and a small amount of soap or ammonia-free Windex.

5. Apply the film to the wet surface, starting from the top and slowly smoothing the film over by hand as you work your way down.

6. Use a squeegee to push any air bubbles out. 

7. Trim any excess material using a craft knife or utility blade.

Hiring a Pro

How well a window film performs depends greatly on how it's installed. Find a local window company to install yours if you’re worried about successfully applying window films. 

Look for an installer who’s certified as a solar control specialist by the International Window Film Association (IWFA), a nonprofit trade association for research and information on high-quality, professional window film. Always inspect the product packaging before it’s installed to ensure it’s the exact product you ordered. 

Most pros will thoroughly clean the windows before custom-cutting and seamlessly applying the film and can complete the work in a day. Be on the lookout for negative reviews online, which generally are related to the film bubbling, cracking, or peeling.

Post-Installation

Once your solar window film is installed, you’ll be happy to know that maintenance is minimal. Wait 30 days for it to adhere, and then clean your windows as you normally would with a non-abrasive cleaner.