What do you think of when you hear the words, “UV light”? Bug zappers? Groovy disco dance floors? Skin cancer? The truth is UV light is everywhere and has many applications. The UV light that concerns us here is the type found naturally in sunlight. UV radiation in sunlight is divided into three categories based on wavelength: UVA, UVB and UVC. UVC is largely filtered out by the ozone layer before it hits the Earth’s surface. UVB is responsible for sunburns and is filtered out in large part by regular windows or auto glass. UVA has the longest wavelength of the three and penetrates deep into the skin, accelerating aging, causing wrinkles and increasing the likelihood of skin cancer. UVA that travels through windows and auto glass can also fade fabric, floors, carpeting and furniture. The problem with UVA is that it is difficult to control with ordinary windows or auto glass. Let’s take a look at UVA and how it can be controlled with proper window installation and auto glass treatment:
Auto glass and UV light. Most vehicles’ windows consist of two types of glass: laminated and tempered. Windshields are laminated and filter out 98 – 99 percent of all UV rays. The side and back windows, however, are typically ordinary tempered glass, which transmit 30 – 40 percent of UVB and a large percentage of UVA rays.
What to do about UVA rays in your car? If you spend a lot of time in your vehicle, dermatologists recommend applying sunscreen to exposed skin while you drive. Another option is to have high-performance window tints applied to your side and back windows that can eliminate up to 99 percent of UV light transmission. If you’re not a big fan of dark tints, clear tints are available.
House windows. The trend in new home construction is towards large window installation. What’s not to love about all that light flooding into your home? Well, for one, UV rays are a problem! Clear glass is good at filtering out UVB rays, but lets most UVA rays through. Low-emissivity (Low-E) glass does, too.
What to do about UVA light in your home? You can specify to have tinted or reflective glass in your window installation, which will filter out 50 – 75 percent of UVA light, but which also blocks more visible light than clear glass. An alternative is to use blinds during peak-light hours and set up work and sitting areas away from windows.