Calculating the Fade Factor Reduction of a Window Film
Calculating the approximate fade factor reduction of a window film is a simple process. Add the Visible Light Reduction percentage of the film to the Total Solar Energy Rejection percentage of the film, then divide by 4. Add 40% to this figure and voila, you have your estimated Solar Fade Factor Reduction Percentage.
Example:
A film with 60% Visible Light Reduction and 55% Total Solar Energy Rejection – (.60+.55) = 1.15, Divided by 4 is .2875 (28.75%), add .4 (40%) to that figure and you have a total of .6875, or 68.75% – this is the total approximate solar fade factor reduction of the film in question.
Clear films with no heat or visible light reduction only have the benefit of the UV blocker added to the adhesive, which qualifies for the 40% added on top of the calculated figure.
This is an invaluable tool to anyone in the process of choosing a window film to protect their funishings from the damaging effects of the sun. Most people discover that the expensive Spectrally-Selective film they were so excited about really doesn’t offer as much protection as a traditional film at half the price. Others are willing to give up additional protection in favor of a higher light level. In either case, with this formula at your disposal you will be able to quantify the benefit of each film you are considering before making your purchase.