UV-C is absorbed by regular oxygen as well as by ozone, so ozone
depletion shouldn't be a problem there.

Yes; that's how greenhouses work.  Window glass reflects most infrared
light, which is radiated heat.

--Bill Thompson

Hey, you're up on your physics!  Are those C-rays going to be a problem with
our depleting ozone layer? or is that something else?

And thanks, what you said just clarifies what the window brochure
demonstrates in pictures.  Also it shows light going through the glass and
heat bouncing off... that seems like an engery efficient mechanism, but
isn't that "greenhouse effect" as well?

Thanks in Advance

Mary Rawle

UV-A, UV-B and UV-C (also know as EUV, for Extreme Ultra-Violet).

When you look at a rainbow, you're looking at the visible part of the
electromagnetic spectrum.  If I could do anything fancy with text,
I'd lay out the colors, but the spectrum looks like this:

(radio
waves)(microwaves)(infrared)(red)(orange)(yellow)(green)(blue)(indigo)(violet)(UVA)(UVB)(UVC)(X-rays)(gamma
rays)

<--- (least amount of energy at this end)--*--(more energy at this end)--->

If your eyes could see infrared and UV, a rainbow would look
wider than normal.

UV-A is the least energetic, longest wavelength of UV light.  It's the next
"color" of the spectrum, just beyond violet.  It passes through glass.

UV-B is a more energetic part of the UV spectrum.  Glass blocks it,
but it will pass through quartz (as in "quartz-halogen lamps".)

UV-C is the most energetic form of UV light; the next step beyond
them is soft X-rays.  UV-C is part of sunlight, but it's blocked by
the atmosphere.  It's only a problem if you're in outer space and
aren't inside a space ship or wearing a space suit--in which case you
have bigger problems than light.

--Bill Thompson

Oh, are those windows going to make a big difference! Wish we could put them
in this old house. (Historic commission will not allow them.)

I don't think I'd sit in the sunlight streaming through but to be able to
allow the light in would be wonderful.

If my memory serves me correctly and it probably doesn't there are two
harmful lights, UV and UB? This is only going to eliminate one of them but
does the other automatically become reduced as it passes through glass?

Maybe J will jump in here and straighten us out. She so good at this stuff.
Bev

...not to be confused with the computer software...

Hello Everyone,

I have a new landlord (this is a *good* thing), and he is replacing the
windows in the duplex unit in which I live.  He is *so* kind as to ask me
what kind of windows I want!  Isn't that great?  It's an older house with
double-hung multipaned glass windows that are pretty but very energy
inefficient.

So.  He has given me a brochure from BetterBilt windows (this is not an
advertisement).  They make window that will help our place look like it did
before, but with double-paned glass, and I do believe it is a single pane
which has bars within that make it look like multipaned glass.

Under "Window Options" it say "Low Emissivity Glass."    It goes on to say
"...plus most of the sun's damaging ultraviolet light is filtered out,
protecting draperies, furniture, carpet [and lupus patients? {my addition}]
from fading.

So.  Have any of you guys had experience with this "Low Emissivity Glass?"
Would I be able to peek out and see the sun shine?  Little kids in the
neighborhood think I am a witch, because I keep all the windows closed, and
wear mostly black (I'm kidding here). But would I be able to open my
curtains?  that might be a landmark day....

Are they good windows?  Do they really help?  To what degree? What do y'all
think?

Thanks in advance,

Mary