Are Your Windows Protecting You from UV Rays?

Are Your Windows Protecting You from UV Rays? - girl at sunny window

Ultraviolet (UV) is a type of radiation generated from the sun and from manufactured sources such as tanning beds. The three types of UV rays are UVA, UVB, and UVC, each classified based on their wavelength. UVC rays don’t reach the Earth’s surface as they are completely absorbed by the ozone layer and atmosphere. UVB is mostly absorbed by the ozone layer, but some UVB rays do reach the Earth’s surface. UVA is not absorbed by the ozone layer so most of the UV radiation we experience is UVA.

UV radiation is not all bad. A certain amount of exposure to the sun helps to create Vitamin D in the body. But, like most other things, it’s possible to get too much of a good thing. Overexposure to UVA and UVB can damage your skin and can harm your pets. It can also cause fading of drapes, furniture and rugs.

So, what is the UV exposure in a sunroom, that place where the glorious sunlight streams into a room.

According to the International Ultraviolet Association and others, almost all UVB rays are well blocked by standard window glass but almost all of UVA rays will pass through and into the home.

There are different ways to protect yourself and your home from UV rays. 

Low-E Window Film

You can buy a Low-E (low emissivity) film to adhere to the windows to block UV rays. The film is a coated plastic that will reduce the amount of UV rays penetrating through the glass with minimal reduction in the amount of visible light. Low-E window films also have the benefit of improving the room’s insulation. Low-E films are fairly durable with an estimated lifespan of 10-15 years, depending on climate and exposure to the elements. Window film can be professionally installed or as a DIY project. If you’re considering window film, though, be sure to check the small print on the warranty on your windows. Many manufacturers will void a warranty if any part of the window is altered.

The manufacturer of the film will often specify cleaning procedures that you should follow but, generally, when cleaning windows with a film, use a soft cloth to wash and dry the surface. Don’t use any ammonia-based or abrasive products as they can scratch the film. You should also wait 30 days after installation of the film before cleaning the windows. 

Low-E Glass

Another way is to install windows with Low-E glass. It has a metallic oxide coating that blocks much of the UV rays while still allowing visible light to pass through. The coating on Low-E glass reflects heat back so it helps your home to stay cooler in summer and warmer in winter. On single-pane windows, the Low-E coating is generally applied to the side facing the interior of the room. Double-pane Low-E windows have the advantage that the coating is sandwiched between the two panes of glass where it won’t scratch off. The only real downside to Low-E glass windows is that it is more expensive than non-Low-E.

How can you tell if your windows have Low-E glass? Because the Low-E coating is invisible, you probably won’t be able to tell just by looking at the window. Hold a lit match or a light in front of the window (a cloudy day or nighttime is the best time to do this). You should see two or four reflections (if the window is single-pane there should be two reflections; if it is double-pane, you should see four reflections). If the reflections are all the same color, you do not have Low-E glass.

Consult and follow the manufacturer’s recommendations for cleaning Low-E glass windows. As a rule, cleansers that are safe for Low-E glass are water, mild dish soap, and vinegar. Don’t use alcohol-based or ammonia-based cleaners, and never use abrasive cleaners or cloths. Don’t use squeegees on Low-E glass. Clean, non-abrasive, lint-free cloths are best.

Replacing Your Windows

Windows, like everything else, have a lifespan. How long a window could be expected to last depends a great deal on the quality of it. A high-quality window should last between 15 and 20 years. Some manufacturers offer a 20-25 year warranty. 

Some signs that windows might need to be replaced include poor window operation, condensation, moisture buildup between the panes, decayed frames, or if your energy costs jump.

If you are planning to replace your windows, consider the energy-saving and UV-protective properties of Low-E.

Sunshine Sunrooms has been helping homeowners design and build beautiful and functional sunrooms since 1993. We offer individualized services based on each of our client’s specific budgets, vision and needs.

Call us at (972) 243-5390 for all your sunroom design, construction, and repair needs or click here to request a quote.

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