majorloser said:
UV (ultraviolet) is a form of radiation. Our sun deilvers Utraviolet radiation in three bands; UVA, UVB and UVC. UVC is commonly used for disinfection purposes due to it's strong germicidal properties. It has to be man-made because it is filtered out by what's left of our ozone layer.
UVA can pass through common window glass and is the primary cause of fading and degradation of items in your home. For those of us fortunate ones that live further South, the sun's rays pass through less atmosphere so less UV radiation is filtered out. As was stated earlier, items that are placed inside an automobile are subjected to UV and heat more regularly. Most automobile manufacturers apply a thin coating to the glass to reflect UV light and equipment manufacturers make their equipment to handle higher ambient heat levels.
To answer your question better, the sun is not the only source of UV emitters in your house. Common exposed halogen bulbs are also emitters. The quartz glass used in halogen bulbs is transparent to UVA and UVB. Most halogen bulbs that are meant to be exposed to human are covered by an external glass outer shell. Those cheap torchier lights are the worst for this.
The cheapest and easiest way to handle this problem with old windows in your house is a sheet of window tint. Can be applied by any home onwer and is available in tints so light you won't even notice it. Newer windows are already coated with a UV protection.
(And yes, I play with UV and ozone as a disinfectant every day in my line of work.)
Well, the reason I asked is that I have read a number of research on its effect on fading. I have seen the energy levels in the UV band compared to the energy in the visible light at the different wavelengths. Very low compared to them.
I have UV filter on the windows, not impressed. I had a roll of wall paper in front of it with the sun shining, maybe a day or so.
You guessed it, nice wash out on the wallpaper where it was exposed to the sun, behind that UV filter.
One only has to look at solid wood kitchen cabinets, well away from windows, behind doors to see the lighter shade where it was overlapped by the door and even at the space between doors darkens.
While UV will harm things, light itself will fade everything in sight over time.
Sounds like the wavelength of UV and above is harmful to those little critters
