Windows, Part 9
You might have purchased these windows because you live on a noisy street or near a
freeway or under an airport flight pattern. These windows do a good job of stopping
sound. There are even special versions of these windows with double thickness glass
(only for the outside pane) and these do very, very well at stopping sound.
Selling you the Windows
The window demonstration is fairly obvious. The window opens
and closes and has a brush-like gasket around the edges to stop
dust from entering the home. The furry gasket may have been made
with special poisons mixed into the plastic before they make the
fiber. These little plastic brushes kill bad things that might
grow in the cracks of the window that the brush material can touch.
Does it work? Sure. Do you need it? No.
There are two major types of thermal and ultra-violet coatings which are used on the
glass in dual pane windows. These special coatings are delicate and are applied to the
surfaces of glass inside the window - not to the surfaces facing outward. One type is
applied in four layers and the other is applied in 12 layers.
The real difference between these two technologies seems to be in the amount of
visible light that can pass through the window. If actually seeing through the window is
important then the amount of light that passes through the window is important.
With some window brands.... “dusk” can come an hour sooner to your home than to
other homes in the neighborhood.
One type of coating system uses thin layers of titanium, silver and tin coatings to reflect
light back and forth between the various coatings and thus give visible light another try
at penetrating all the way through the coatings. It does work (PPG).
Part of the sales demonstration will include the use of a heat lamp to shine through the
window and let you feel the heat through the “bad” window and then how little gets
through the “good” window. The salesman will use a red heat lamp. He will not use a
white lamp. If he used a white lamp then you would see - plain as day - how much
visible light is stopped and how dark your house will be if you buy those windows.
Further, he will tell you about “energy credits” from your power company. What he will
not tell you is that most of the time you need to have the windows not only what is
called “Low E” or “Low E Squared” but also tinted to get that energy credit. Lastly, the
