UV Fading Protection:
Damage from Ultraviolet Radiation

Furniture. Carpets. Draperies. Artwork. All can be severely damaged by fading. Industry experts estimate that in the United States alone, fading causes hundreds of millions of dollars of damage to fabrics and furnishings every year.

But what exactly causes fading? While many people would answer "sunlight", most fading damage is caused by only a small part of the sun's energy- the portion called ultraviolet radiation. Though ultraviolet (UV) comprises only 2% of the sun's energy, it accounts for an estimated 60% of the fading damage to fabrics and furnishings.

Windows and Fading
Sunlight through windows has long been associated with fabric fading. To suppress fading damage, homeowners often install lined draperies and curtains, shutters, tinted or reflective glass, or dark, "stick-on" window films.

While all of these "solutions" reduce fading, they also prevent light from passing freely through the window, negating much of the value of having windows in the first place. Draperies, curtains, and shutters all require the resident to operate them faithfully, while tinted glass and films dramatically alter the appearance of windows from both inside and outside.

Ideally, a window would block the damaging UV rays that cause fading, while letting light pass through. Ordinary clear window glass lets in about 70% of the sun's UV radiation. New varieties of high-performance clear window glass, commonly called "low-e" glazings, provide some protection from UV radiation. Even the best of these, however, still transmit 26% of the damaging UV rays.

Introduction of SeriousGlass  Fading Protection
A major benefit for SeriousGlass products is the ability to block more than 99.5% of damaging ultraviolet radiation, while still looking clear and colorless. For the first time, significant fading protection is available in clear-glass residential windows.

How SeriousGlass Fading Protection Works

The Solar Spectrum
The sun's energy is made up of three distinct parts, as shown in Figure 1: ultraviolet radiation, visible radiation, and near-infrared radiation. What make these types of radiation (or energy) different from one another are the wavelengths that characterize them, much like TV and radio stations use signals with different wavelengths. These wavelengths are commonly measured in nanometers (nm). A nanometer is very small-even something as thin as a human hair is over 100,000 nanometers thick.

Ultraviolet radiation, which is invisible to the human eye, has the shortest wavelengths of the three types of solar radiation, from 300 to about 380 nm. The next-shortest wavelengths are those of visible light from about 380 to 780 nm, while the near-infrared radiation (sometimes called invisible solar heat) has the longest wavelengths, from 780 to 4045 nm.

Relative Damage of Different Solar Wavelengths
Work by numerous scientists, including Albert Einstein, has proven that the shorter the wavelength of solar radiation, the greater the fading damage potential. Therefore, ultraviolet radiation is the most damaging, followed by the shorter-wavelength visible light. Visible light at wavelengths above about 600 nm as well as near-infrared radiation seems to cause very little fading.

The most authoritative research on quantifying fading damage was done in the early 1950's by the United States National Bureau of Standards (NBS). This research was undertaken for the U.S. Library of Congress, in order to design a glass filter to protect the original copies of the Declaration of Independence and the Constitution. The NBS found the relationship between the wavelength of the radiation and the relative damage to be as indicated in Figure 2.

Using this relationship, scientists have calculated that blocking all the ultraviolet radiation portion of the solar spectrum would not eliminate fading damage for most fabrics, but will slow down the rate of fading by a factor of about three. That is, a fabric that will fade by a certain amount in 3 years under normal solar exposure could take about 10 years to fade to the same point if the ultraviolet radiation is eliminated.

Breakthrough in Fading Protection
The unique combination of glass, suspended film and gas make SeriousGlass packages the best option for  both energy control and fading protection. SeriousGlass has been engineered to transmit parts of the sun's spectrum, such as light while blocking others, such as UV radiation.