UV rays fade fabrics: how window coatings can help
August 29, 2011
Today's windows play an important role in the energy-efficiency of homes. The best sport ENERGY STAR and NFRC (National Fenestration Rating Council) labels. These labels help you choose excellent performers not only by climate and resistance to thermal conductivity, but even by things such as air leakage and condensation resistance. Nothing is directly stated on these labels about another homeowner concern--the ability of the sun's ultra-violet (UV) rays to fade and degrade carpets, fabrics, and artwork. So if you want to figure UV protection into the complete financial affect of your window replacement cost, where do you look?
Low-E window glass reduces UV damage
According to an online article in Fine Homebuilding magazine, a test called the Krochman Damage Function measures damage caused by UV and other visible light. Andersen Windows & Doors states that an uncoated dual-pane window transmits 62% of UV light. Fine Homebuilding's article says that Low-E coatings (microscopic metal coatings on the interior sides of multi-pane glass) cut UV transmission by more than 75%. And yes, that refers to non-custom, off-the-shelf window models. That makes the NFRC's Visual Transmittal rating important if fabric fading and sun degradation are important to you. The lower the Visual Transmittal rating, the better the UV protection.
You can further protect art and photographs that are mounted under glass by reframing them with UV protection glass. Heirloom photos should be hung away from sunlight. Using one of the many new sheer synthetic window shades during the sunniest hours may also help.
Window brands with Low-E glass
Fortunately several manufacturers have models with coated glass. Not every line from a manufacturer has these coatings, so shop by model line as well as brand:
Your local building supply store or window store often has actual sample windows for you to look at. They can tell you if Low-E coated windows are offered in certain lines within a brand or as an option you can choose from certain models within a brand. With Low-E coated windows you can have it all--UV protection, greatly improved thermal control, and even up to a $500 tax rebate if windows are installed before the end of 2011.
About the Author
Suzanne Clemenz designed her passive solar home and remodeled two others. She worked with architects and contractors on floorplans, electrical, painting, windows, flooring installations, flood prevention walls and stonework, major drainage issues, an irrigation system and landscaping. She also managed a carpet and draperies showroom.