Window film energy saving performance is based on the amount of visible and infrared light absorbed or reflected by the film. UV light also contributes to heat gain, but because most window films reduce 99% of the UV, we’re not including this factor as a variable.
The more visible and infrared light you reject, the more energy you save. The maximum available performance for architectural window films is around 80% heat reduction. These high-peformance films have a reflective exterior appearance and are usually only applied to commercial windows and skylights.
Most residential window films reduce around 55% of solar heat from entering the home. These products are designed to have a subtle appearance (lighter in color and less reflective than high-performance films) and sacrifice performance for aesthetics.
Spectrally-selective films can reduce the same level of heat as traditional home window films without being reflective or dark. These films reject a high level of infrared light, so homes in colder climates will get the added benefit of increased heat retention in the winter months. The combined energy savings throughout the year comes to around 35%-50%.
There is no way to accurately calculate how much energy window film will save you in your specific application. The compass orientation of the glass, the number of windows, size of the windows and type of glass you have are all factors that affect your bottom line energy savings.
If your windows face north and you get little or no direct sunlight through them, window film will do little to help save energy. Heat issues in these situations are more often caused by poor circulation and/or the room being located on the top floor of a multi-level home.
If you have windows that face south and get direct sunlight for most of the day, you will quickly notice a significant difference in energy expenditure. Similarly, a “wall” of windows that face east and/or west will also exhibit a high energy savings after the application of film.
As a general rule, energy saving window film will pay for itself in energy savings between 2 and 5 years after you have it installed. Review our article on what window tinting costs to get an idea of how much your project will be.
If you live in the Chicago area and would like to know exactly what your installation will cost, you can set up a free estimate with us and see samples in person. If you would like to see how popular window film styles will perform and look right now, visit our web site at www.precisefilm.com.