Sound attenuation question in replacement windows
I'm buying replacement windows (double hung) for my apartment, which face a busy street. It's a medium sized installation with two double hungs on each side of a 3 foot picture window panel. The current windows are 20+ yrs old and they are really bad in terms of giving me a peaceful room from the traffic, sirens, horns, etc.
I've narrowed things down to two quotes on different style windows dbl pane windows:
(1) has an IGU of 7/8" total consisting of 1/4" laminated glass, 3/8" air space, 1/4" laminated glass.
(2) has an IGU of 1.25" consisting of 1/8" lami, 1" air space, and 1/8" lami. [thicker frame, more cost]
Which will one will give me better sound attenuation from traffic noises? I'm torn b/c one has the thicker laminated glass panes, but while the second has thinner glass there is almost double the dead air space. Or will they basically be close to the same STC/OITC for attenuation and I should go with other factors like price, etc? Assume both are triple weather stripped and otherwise air-tight.
I can't do a second interior window like a Citiquiet or anything due to my blinds and design of the room. I'm also stuck with double hung since that is my condo's required style....
Any thoughts would be greatly appreciated...thanks!
This post was edited by sippelmc on Sun, Nov 24, 13 at 12:42