Soundproofing: Three things you should considerSource Post: http://www.replacement-windows.com/windowbb/viewtopic.php?p=5720
Although I am not recommending a particular window, I will offer a few comments on soundproofing, or how to make a quieter window. Hopefully, these comments will help you a bit when researching the best possible solution for your noise issue.
One consideration though. That is a large window and as such it will be a bit harder to quiet than a smaller window...but the information still applies.
Windows are rated as to their ability to deaden or attenuate sound based on something called an STC or Sound Transmission Class (walls and other building components use the same system, but here we are considering windows).
STC is an average of an objects ability to attenuate sound across the entire sound frequency spectrum. STC does not provide specific frequency-deadening information which is really what is needed if you want to block a specific type of unwanted noise; for example traffic noise.
As humans we are born with the ability to hear from approximately 20 to 20,000 hertz. Hertz, or Hz, is how sound frequency is measured - like electricity is measured in volts, for example.
By the time we are teenagers we have generally lost the ability to hear above about 13,000hz which as I remember is something mother always warned us about - going deaf - or was it stop or you'll go blind? I always get those confused.
Anyway, traffic noise is generally a low frequency sound, and unfortunately, low frequencies are much harder to attenuate (opposite of amplify) or block than are higher frequencies...consider how often you hear the base sounds from the neighborhood kid's car stereo and not the higher pitch tunes when he is coming down the street.
When considering windows, there are generally three options available for maximum possible sound attenuation.
First is laminated glass.
Second is a wider airspace between the lites.
Third is different thickness lites within the IGU or Insulating Glass Unit.
Fourth would be a combination of all three.
Airport windows, for example, will generally have laminated glass on both sides of the IGU in an aluminum frame and with a maximum airspace between the lites. In an airport the primary concern is sound attenuation and energy efficiency is secondary. I mention this because the width of the airspace and the choice of window framing material affects both sound and energy efficiency.
Some folks will suggest triple pane glass for its sound deadening ability. And while triple pane is a slight improvement over standard double pane at lower frequencies due to the additional density of the extra lite, overall there is no difference in STC rating between triple and double pane provided that the overall airspace between the panes is constant between the two constructions. In other words, consider a triple pane with two 1/4" airspaces and a dual pane with a single 1/2" airspace...both using 1/8" glass...the STC will be identical if the IGU's are the same dimensions.
Using one thicker (3/16") and one thinner (1/16") lite in an IG construction will also help deaden sound because each lite is "transparent" to a different frequency and each lite will then attenuate the frequency that the other lite "passed".
If so, and if you would like me to continue I would be more than happy to do so.
And, as always the quality of the construction and especially the installation cannot be overstated! Based on the size of the unit, I am assuming it is fixed (not an operator)...that is a definite advantage when attempting to stop noise from coming in your house.
Source Post: Street Noise problem - is there a real solution in vinyl?
Posted: Wed Feb 08, 2006