It's called low e glass and it's used to cut cooling costs in southern
desert climates.
hank wd5jfr
"Roy Lewallen" wrote in message
...
A word to the wise for people who expect to be able to operate from a
hotel room.

I recently returned from rainy Arizona back to my home here in sunny
Oregon. While in Tucson, I turned on my VX5 to get a weather report from
the National Weather Service, and was surprised that I couldn't get the
NWS on any of their frequencies from my hotel room, even with the radio
against the window. But remembering an experience I had some time back
with a rented car's windshield, I opened the window and -- voila --
there was the NWS. It seems that some hotel room windows are now being
coated with the same conductive stuff they use on some car windshields.
The attenuation, at least at VHF and GPS frequencies, is impressive.
Because I think the purpose is blocking UV (and maybe near IR?) to
reduce air conditioning loading, I'd expect it to be much more common in
hot, sunny climates than elsewhere.

And windows in high-rise hotels often don't open more than a crack, if
at all.

Roy Lewallen, W7EL