sun reflective films for windows
Sun reflective window films are great to reduce solar heat gains and glare, namely in hot climates. They can block up to 75% or the solar heat in single-pane glass windows, and 30% of the visible light.
Metalized vs. tinted films
Be aware with the type of window film.
Tinted films (to simply color the window glass) are inexpensive but ineffective at blocking solar heat.
Modern metalized plastic window films are a much better choice.
Prices vary a lot. They may depend on the quality of the film, but also on brand policies. Films in big home improvement stores and Online are a lot cheaper.
Expect Online prices around $40-$50 for 38/48 inches by 15 feet (see Amazon.com for reviews: Window films) rolls, but a lot more elsewhere, namely for films involving professional installation.
Some manufacturers require their films to be installed professionally, while others are promoting DIY installation. The installation is moderately difficult, and requires an absolutely clean glass surface.
When not to buy window films
Spectrally selective window films can be a very effective and low-price choice to reduce cooling bills in hot climates.
But even the best films are rather ineffective or without significant advantages in homes with moderate or good energy-efficient windows.
The pros and the cons
Plastic window films can provide hundreds of dollars of energy savings each year, in hot climates. Other advantages: films can also cut glare and reduce furniture fading and, in some cases, winter heat loss…
But pay attention to their quality (there isn't currently a rating system for films, involving a significant number of manufacturers) and their possible side-effects: films often reflect indoor light inward, and block views at night, and some of them are not perfectly clear.
Most homeowner complaints about window films involve their installation. Even films designed for DIY installation are not easy to apply.
Professional installation can be an important factor for the success and performance of window films, but contractors may charge you much more than the cost of the film.
Energy Efficient Windows Guide
Window Energy Rating Labels
Windows for cold, hot and mix climates
Energy-efficient Windows: Costs and Payback
Window Installation and Manufacturers
Window sizing and placement
Old Windows Replacement: How Effective It Is?
Low-E Glasses and Warm Spacers
Window Frames and Sashes
Types of Window Operation
Casement Windows Energy Efficiency
Sliding Windows Energy Efficiency
Interior and Exterior Storm Windows
How effective are Storm Windows
Clerestory Windows for Ventilation and Passive Solar
Cooling and Shading Devices for windows
Awning Types and Styles
Window and patio awnings for cooling and shading
Home Window Shutters
Shades and Blinds for your Windows
The Best of Residential Windows