The current trend in commercial building remodeling is to replace old windows with new, modern, dual-pane, wood- or vinyl-frame replacement windows. However, what is trendy isn’t always best.
Replacement windows are fine if a new look and some energy savings is the goal, but will do little if reducing outside noise to get peace and quiet indoors is the real problem.
The challenge is that replacement windows are not designed to reduce noise, and the vast majority of exterior noise enters through windows, not walls. So, when tenants talk to contractors to help them create a cozy sanctuary in their buildings, it often makes more sense for them to improve the existing windows rather than replace them.
That’s why a cost-effective countertrend is developing to keep existing windows but enhance function by placing a soundproof, matching inner window inside the existing windows. This method can stop up to 95% of outside noise, while enhancing energy savings and safety. It not only provides extra thermal insulation, but also is a virtually shatterproof barrier that deters intruders.
Because no window replacement is required, the installation process can take as little as one hour per window, which minimizes disruption.
Keep the Noise Out
From screeching traffic and blaring car/train horns to barking dogs and roaring leaf blowers, dual-pane windows will not keep out the noise because they are not designed to do so. The problem with a typical dual-pane window is that the dual panes act like a drum and reverberate in response to external noise vibrations. The result is noise, as sound vibrations transfers through the panes. Additionally, the seals of most dual-pane windows degrade in a few years, which allows even more outside noise to pass through.
Some replacement window manufacturers tout single-pane acrylic windows as soundproofing. However, acrylic panes in typical ¼-inch thicknesses lack sufficient mass to stop much noise. Acoustic testing has demonstrated that a single-pane acrylic window must be at least 3/8 of an inch thick before it provides a good acoustic soundproofing value.
An even more effective solution incorporates recording studio soundproofing technology to block up to 95% of external noise penetration, which can make unwanted noise sound as though it is at least two football fields farther away.
This approach first dampens sound vibrations with an inner window of laminated glass installed behind the existing window. The lamination acts like a finger placed on a vibrating wine glass to deaden the sound vibrations when struck. An inner layer of tough polyvinyl, similar to that used in car windshields, further dampens sound vibrations.
Next, air space of two to four inches between the existing window and the soundproof window also significantly improves noise reduction because it isolates the window frame from external sound vibrations.
Finally, spring-loaded seals in the second window frame put a constant squeeze on the glass panels. This prevents sound leaks and helps to stop noise from vibrating through the glass. The spring-loaded seals are designed to stay acoustically sound for decades.
Energy Efficiency
Typical windows are notorious causes of heating and cooling loss. They transfer heat/cold by thermal conduction through the panes and glass surface, so additional heating or cooling is required to keep everyone comfortable.
Air leakage through window seals that crack over time also worsens the problem. While single-pane windows transfer the most heating/cooling, even dual-pane windows may be insufficient to keep buildings sufficiently warm in winter and cool in summer without raising utility costs.
As a solution, adding an inner insulating window to existing windows can improve thermal efficiency. This approach provides an additional layer of insulation with better insulation values than the best double-pane windows, and substantially improves insulation values for dual-pane windows as well. This can reduce heat loss by 77% or more for single-pane windows, and heating/cooling bills by up to 30%, while stopping air infiltration for further energy savings and greater comfort.
Improve Security
Another important side benefit to this soundproofing approach is security enhancement, since its construction helps to deter burglary/breaking and entering through typical windows.
While standard windows can be shattered by a sharp blow, the laminated glass used in such soundproofing offers significant break in protection because it is shatter resistant and tends to remain intact even after repeated blows. Such laminated glass is actually a major component of most bulletproof glass.
The Bottom Line
If tenants want to change the curbside appearance of their building, they still might consider replacement windows. But if stopping outside noise from driving them crazy during the day or keeping them up at night, cutting energy bills or improving security is the goal, then they will want to add an inner window instead of replacing the existing window with inferior options.
As an added plus, the cost can often be less, depending on window size or the noise reduction sought. Installation can take a fraction of the time of replacement windows, leaving contractors more time to move on to other jobs.
