Sound insulation on a new window
geoffhazel
| Posted in Energy, Heating & Insulation on
Client is in a condo on the ground floor. Units are just 2 yrs old. Window is vinyl, double glazed (of course) with two sliders on the ends. Window is 7′ wide 4′ high.
She is complaining about traffic noise. There is a main road about 100 yards away, and I can hear it. When cars go by you can hear the “wooshing” from their tires. It even sounds kind of like it has reverb on it.
One option is to replace the window — I figure it’s probably some “builder grade” and there would be better sealing windows out there for noise.
Another option would be to get a second custom made window fit into the opening on the inside.
Thoughts? What would you consider to be an effective and not horribly expensive fix here?
Replies
I was once in a hotel in Toronto where a busy train track ran outside not 50 feet away. Was there for two days before I noticed, since they had doubled-up the windows and patio door on that side. Doubling is probably the most effective sound-reduction approach if you have the thickness.
What do you mean 'doubling the windows'?
Basically two copies of essentially the same window, one outside the other. Of course you need windows that will work this way and still be openable (if opening is desired) -- double-hungs or sliders.
As I stood before the gates I realized that I never want to be as certain about anything as were the people who built this place. --Rabbi Sheila Peltz, on her visit to Auschwitz
http://www.soundproofwindows.com/technical.html
Or you could add a laminated glass storm panel.
Jeff
Mass will help control sound. So glass that is thicker (e.g. 3/16 rather than double strength). Triple glass. The other poster said laminated storm ... not sure how that would happen. Another option would be Heat Mirror glass or double heat mirror. It has the mylar film suspended in the middle. Great for sound. The glass is expensive (depending on your location/availability). Benefits: sound and GREAT energy performance. If the window is exposed to the sun, you have the option of adding solar control when you order it (e.g. tinting, adjusted low-e coating, etc.).
If the frame is relatively 'cheap', then that will contribute as well. I assume the install was good (i.e. good sealing all around)? What is the overall glass unit thickness?
Laminated glass is what they use in noise-reduction windows. The PVB interlayer decouples the outer and inner layers of glass which aids in acoustical control.
Edited 7/29/2009 4:02 pm ET by Jeff_Clarke
Jeff,The plastic layer is performing more of a damping function than a decoupling function in laminated glass. The two layers of glass are very rigid, and the plastic interlayer is soft. The bonded soft layer is a constrained damping layer that dissipates incident acoustic vibrations.In any event, I totally agree that laminated glass is the way to go. Another option for the OP to consider is to reglaze his window with insulated glass that has the 1/4" laminated glass on the room side. This works best on better quality windows that accept thicker insulating glass units.Your original suggestion of laminated glass storm panels is also good, and does not involve throwing away good new glass.Bill
The plastic layer provides the viscoelastic member of a classical layered damper. Basically you interleave layers of an inelastic material (the glass) with layers of a viscoelastic material (the plastic). The same is done in aircraft with layers of metal foil and adhesive.
As I stood before the gates I realized that I never want to be as certain about anything as were the people who built this place. --Rabbi Sheila Peltz, on her visit to Auschwitz
What Jeff Clarke is suggesting guarantees results. Other solutions may or may not work. With a bit of bad luck, depending on the frequencies of the sound, you could conceivably make things worse!
Best is to replace the window with one specifically designed, tested, and certified to reduce sound.
Tire noise can sometimes be lessened by some type of barrier, too. Such as a berm, solid fence, etc. Conifers can help, too, but you pretty much need a continuous 50 foot deep planting of them to be noticeable.
Given your description I suspect that the sliders aren't sealing out the noise very well. One hundred yards and double pane glass should be enough to dissipate most (80%-90%) of the tire noise so sealing problems should be tested for first.
If you're unable to seal those two sliders well, perhaps a good solution would be one fixed pane window, tripe glazed.
BTW, I'm sitting next to a double pane vinyl double hung replacement window, http://www.milgard.com . It faces a busy street which begins fifty yards away. When the original single pane doug fir double hung unit was in that opening the noise level was unpleasant a lot of the time. The replacement unit stops a great deal of that noise, like 80%-90%.
Edited 8/3/2009 1:19 pm by Hudson Valley Carpenter
Tripe glazing may cut out the noise, but it leaves one wondering about the odor.
As I stood before the gates I realized that I never want to be as certain about anything as were the people who built this place. --Rabbi Sheila Peltz, on her visit to Auschwitz
Just got a reference that might interest you on glass designed to control sound:
http://www.soundproofwindows.com/architect
I didn't visit this, but check it out. Might learn something. They even have STC ratings (ratings on sound transmission).
Good link - if you read the test report - http://www.soundproofwindows.com/architect/specs/WEAL-TL08-291-14-3AS-51STC.pdf you'll see that the assembly includes 7/32" laminated glass with 0.030 pvb interlayer.
Jeff