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interior storm windows for sound insulation?

Posted by dieselman8 (My Page) on
Thu, Mar 31, 11 at 21:36

Hello experts!

I live close to the "L" (elevated train) in Chicago and I'm considering interior storm windows with laminated glass to help dissipate the noise coming from the passing L trains 100 feet from my home.

Specifically, the ones I'm considering are made by Mon-Ray and they can fit 1/4" thick laminated glass. However, based on the "impact noise" coming from the passing trains, one contractor recommended 1/2" laminated glass instead which would require a different, thicker, window all together. The other contractor disagreed. He believed that the 1/2" would result in a net loss due to the loss of airspace between the existing window and the interior storm window. The 1/2" would require a different frame all together. I have pretty deep window sills (6.5"), but obviously, but I want to spare an inch or so for shades so they're still within the window opening for aesthetic reasons.

So, who's right here? I want to get this right the first time since these windows will set me back a nice chunk of change.

Follow-Up Postings:

RE: interior storm windows for sound insulation?

Ask what the OITC of each window is. The higher the number the better sound dampening the window has.

RE: interior storm windows for sound insulation?

I'm not sure. The windows I'm considering are Mon-Ray storm windows with 1/4" laminated glass, or the DeVac 400 series with 1/2" laminated glass. I haven't been able to get any hard numbers, but they claim that their windows are great for sound abatement.

I've also looked into Soundproof Windows, but they seem to charge a large premium for their windows while only using 1/4" laminated glass. I would also have to pay an extra few hundred dollars to have the windows shipped from Nevada. So, they're at the bottom of my list at this point.

RE: RE: interior storm windows for sound insulation?

I suppose my real question comes down to this: All things being equal, whether a 1/4" of additional laminated glass thickness is better than a 1/4" loss of dead airspace between the two windows for purposes of sound abatement.

RE: interior storm windows for sound insulation?

You are way to hung up on glass thickness and dead air space, when what you should be focusing on is the laminate thickness. A laminate thickness of .90 mil is going to give you greater sound abatement than a .30 mil. As I said before, you need to ask what the OITC is. There are other factors that determine STC other than glass thickness or the size of the gap between 2 panes of glass. Varying the thickness of the glass is also a factor in sound abatement. Again, you need to find out the OITC and quit driving youraelf crazy trying to understand something that has little consequence. If the salesman continues to dodge your questions then tell him to give you a call once he finds out what it is and in the meantime, find another company that has a salesman who knows what he is selling and can answer your questions. This guy you have now sounds more interested in selling you something than in solving a problem. Also make sure you get the OITC and not the STC as the STC in your situation is not as important.

RE: interior storm windows for sound insulation?

I hadn't considered the laminate thickness. That's a very good point. When you say varying the thickness of the glass, are you referring to varying the thickness of the two panes of glass in the laminate?

RE: interior storm windows for sound insulation?

STC/OITC is affected by 3 things.

Mass, Airspace, and Thickness.

An object with more mass will be better at blocking sound.

The larger airspace will be better at dissipating sound.

The thickness and varying thickness of the lites (glass) will cancel out a larger frequency range.

Here is a link that might be useful: STC explanation

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