Noise Reduction Windows

A Closer Look At Noise Reduction Windows

If building or remodeling a house in a noisy neighborhood, an investment in noise reduction windows may be worthwhile to pursue. Outside noise can enter a house through walls, windows, cracks and openings, and it would pay to investigate the existing construction of a house before spending too much money on noise reduction windows. Windows are expensive, and even if you live in a small house you may be surprised at the total number of windows you have.

Noise reduction windows may not be necessary in all parts of a house, but likely would be desirable in those rooms where one spends the most of one's time, certainly the bedroom, and probably the family room or dining room as a minimum. Just bear in mind that you can buy the best noise reduction windows on the market and they'll do little good if they don't fit snug or if the exterior walls lack sufficient insulation.

Dead Air Helps - There are several ways to deaden the amount of noise that will be transmitted through a window. Double panes can be effective as long as the seal between the panes is tight. Dead air serves as a good sound insulator. Not perfect, but good. If a double pane doesn't do the trick, a triple pane might, although the use of triple pane windows is not very common, and in some cases still may not damp sound vibrations effectively.

Thickness Counts - The thickness of the glass in a window will usually do more to filter out sound than will a double pane. Stores having thick plate-glass windows, some of which are double paned, usually do a good job of keeping out street noise, although one will still hear loud trucks and sirens. There are few windows that will completely block out noise of that kind.

The thickness of a pane of glass filters out noise of some frequencies better than others, and a thick pane usually filters out the entire sound spectrum of frequencies much better than a thin pane, which may allow certain frequency ranges to pass through. Double-paned noise reduction windows will usually have two panes of different thicknesses to filter out as much of the sound spectrum as possible.

Keeping The Decibels Low - A building contractor or architect may throw some sound reduction terms and numbers at you which may not make much sense. One term is the decibel. A decibel is the unit of measure for the volume of noise. The formula for calculating decibels is such that for each 10 decibels measured, the perceived volume of sound is doubled. The average sound level in a neighborhood on a quiet Sunday morning may be 20 decibels (the abbreviation is db). On a busy week day it may reach 25 db and on a Friday or Saturday night 30 db if there are lots of parties. Sitting in front of a loud TV may expose you to 40 db, and a rock concert may hit sound levels of 60 db, 4 times louder than your TV and 16 times louder than your neighborhood on a Sunday morning. That's loud!  Noise reduction windows which reduce the noise level by 20 db till reduce the noise by a factor of 4.

Sound Transmission Ratings - The other term you may hear is the STC rating. STC stands for Sound Transmission Class, and the higher the STC rating for a window, the more sound that window will block out. A typical single pane window will have an STC rating of around 26, maybe a bit higher if the pane is thicker. A dual pane window will have an STC rating of anywhere from 28 to 33. A window which has been specially designed for noise reduction by using special glass, dead air gaps, or more likely, a laminate film between the panes, can have an STC rating in the high 40's. Not surprisingly, the cost of a window normally increases as the STC value increases. The STC measurements are on a logarithmic scale, like the one used in measuring the strength of earthquakes, the Richter Scale. A change in an STC rating of 10 units corresponds to a 90% reduction in the transmitted noise level.

Look for higher STC ratings or large values in decibel reduction when selecting noise reduction windows, bearing in mind that the larger the numbers, the more dollars will be involved, although peace and quiet can be worth a lot.