Calculating STC

[velar]

My issue is finding windows that can deaden sound. I have read numerous posts here and I feel confident on the technical aspects to reduce the sound, but what I'm trying to figure out if there is a formula that I can use to get to an approximate STC rating without relying on the vendor telling me their rating. I would rather try and calculate it myself.

FYI...I'm only using STC in order to compare windows. I also realize installation is a key component.

I have one vendor who said they have an STC over 40 with the following info: 1/8" x 1/2" AS x 3/16" with the AS being filled with Argon. The vinyl frames are also foam insulated. Will that get me near 40? Is there a formula/chart that I can reference? Also, I'm trying to stay away from laminates due to cost (9 windows need to be replaced) even though that will probably do the most to help in deadening the sound.

Any guidance will be greatly appreciated.

[Windows on Washington]

http://www.archtest.com/testing/faqs.aspx?id=2

http://www.viracon.com/acoustic

Those are the sites that I usually go to for research.

[velar]

Thanks for the links. The info. provided at those sites are very helpful.

[Oberon]

My issue is finding windows that can deaden sound. I have read numerous posts here and I feel confident on the technical aspects to reduce the sound, but what I'm trying to figure out if there is a formula that I can use to get to an approximate STC rating without relying on the vendor telling me their rating. I would rather try and calculate it myself.

FYI...I'm only using STC in order to compare windows. I also realize installation is a key component.

I have one vendor who said they have an STC over 40 with the following info: 1/8" x 1/2" AS x 3/16" with the AS being filled with Argon. The vinyl frames are also foam insulated. Will that get me near 40? Is there a formula/chart that I can reference? Also, I'm trying to stay away from laminates due to cost (9 windows need to be replaced) even though that will probably do the most to help in deadening the sound.

Any guidance will be greatly appreciated.

+1 WoW, great links!

I would suggest that any company that claims an STC of "over 40" with a 1/8" x 1/2" AS x 3/16" IG, is being a little bit optimistic.

By way of comparison, a 1/4" lami / 1/2" AS / 3/16" has a measured STC of 39.

Although it is possible to calculate an estimated STC, for accuracy STC has to be measured.

Argon has absolutely no effect on sound performance.

[Randy]

Argon has absolutely no effect on sound performance.

Good point Oberon, as this is one of the most common misunderstandings out there. Most homeowners, and I dare say, most window salesman believe that argon does dampen/block sound.

[Oberon]

I have read that one of the few gasses that can affect noise thru the IG airspace is sulfur hexafluoride.

Now if anyone actually knows where to get sulfur hexafluoride.....

[Windows on Washington]

There goes Oberon...making more sulfur hexaflouride again.

Lay off the cabbage buddy.

[Oberon]

Naw, my gas of choice is nitrous oxide.

I LIKE going to the dentist!!

[Windows on Washington]

NOS!!!!

I thought we were talking racing baby...

[Oberon]

well that too!!!