Are Triple Pane Windows Better for Noise Reduction?

Sound Transmission

• A triple-pane window won’t be as effective as it could be at blocking noise if its three panes aren't properly spaced. Sometimes all three panes are so close together inside a frame that their total thickness measures just 1 inch. In such cases, the thin air spaces between the panes aren't large enough to deaden the sound vibrations that travel from one pane to the other. By comparison, a double-pane window with at least a 1/2-inch air space between the two panes would block exterior noise better than a triple-pane window with panes that are too close together.

Pane Spacing

• Separating panes by 1/2 inch to 3 inches creates dead air spaces that prevent the transmission of noise through multiple-pane windows. The larger air spaces isolate the vibration of each pane as sound travels through it, which interrupts the transmission of noise into a home. Bear in mind that the weight and cost of a window increase as more panes are added to it.

STC Ratings

• Another way to determine how well a triple-pane window blocks exterior noise is by checking the manufacturer's Sound Transmission Coefficient STC rating on the window. Windows with high STC ratings are better at reducing noise transmission. A standard double-pane window generally has an STC rating of 27 to 32, according to trafficnoise.org. Adding another pane to the window, however, can raise the STC rating to 39 or higher, provided the three panes are spaced far enough apart to absorb noise transmission.

Considerations

• Installing a few triple-pane windows with high STC ratings to save money won't be effective for reducing exterior noise if they're mixed with windows that have lower ratings. For example, a standard single-pane window may have an STC rating as low as 22. If your home is near a road, it’s important to replace the windows that are parallel and perpendicular to the road to reduce exterior noise, according to trafficnoise.org. That would require replacing all of the windows on the front and sides of your home if the front of your house faces the road, however.