Acoustical Glass

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Author Message Robin E. Snyder Senior Member Username: robin Post Number: 87 Registered: 08-2004 Posted on Tuesday, February 13, 2007 - 11:23 am:    Is there such a thing? I did a quick search of some websites and didn't find anything. Specifically, I am working on a high-end aircraft facility and they want something that will lessen the sound of the airplanes along the viewing wall. Anyone have experience w/airports? Helaine K. (Holly) Robinson CSI CCS CCCA Senior Member Username: hollyrob Post Number: 266 Registered: 07-2003 Posted on Tuesday, February 13, 2007 - 11:29 am:    You might want to look at laminated glass and blast-resistant products. Sheldon Wolfe Senior Member Username: sheldon_wolfe Post Number: 230 Registered: 01-2003 Posted on Tuesday, February 13, 2007 - 11:44 am:    Try www.kriegerproducts.com, www.overly.com, www.industrialacoustics.com. Richard Baxter, AIA, CSI Senior Member Username: rbaxter Post Number: 40 Registered: 12-2004 Posted on Tuesday, February 13, 2007 - 12:11 pm:    What we’ve done in the past is used 2 lites of laminated glass with a sealed airspace between them. The outer lite was installed at an angle from the inner lite. I can’t say what the ideal angle needs to be or how thick the glass lites need to be for the amount of noise or sizes of glass in your situation. An acoustical consultant may be able to determine that for you. George A. Everding, AIA, CSI, CCS, CCCA Senior Member Username: geverding Post Number: 253 Registered: 11-2004 Posted on Tuesday, February 13, 2007 - 12:14 pm:    It's not just the glass but the whole assembly. Try Visionwall High-Performance Curtain Walls. www.visionwall.com Richard L Matteo, AIA, CSI, CCS Senior Member Username: rlmat Post Number: 194 Registered: 10-2003 Posted on Tuesday, February 13, 2007 - 01:10 pm:    Robin, I concur with Helaine. Laminated glass is the best way to go. Try this web site at Solutia. The have an "Acoustical Glazing Design Guide" http://www.saflex.com/pages/technical/acoustical.asp Dale Hurttgam, NCARB, AIA,LEED AP, CSI Senior Member Username: dwhurttgam Post Number: 19 Registered: 10-2005 Posted on Tuesday, February 13, 2007 - 02:51 pm:    You succeeded in having me do something that I have not done in a couple of years - open a Sweet's Catalog. I couldn't readily find it on the Web - but I remembered that there was one glass manufacturer that always featured one of their products for airport use in their Sweet's brochure. I found it - although not presented quite as prominently as I recalled. Globe Amerada Acouta-Pane (developed in 1963 for airport use). Never have used it - but their brochures must have been effective because I still remembered it. Colin Gilboy Senior Member Username: colin Post Number: 81 Registered: 09-2005 Posted on Tuesday, February 13, 2007 - 03:12 pm:    Global Security Glazing http://www.security-glazing.com/ Acousta-Pane http://www.security-glazing.com/GlobalBrochure.pdf (bottom of brochure) John Bunzick, CCS, CCCA Senior Member Username: bunzick Post Number: 653 Registered: 03-2002 Posted on Tuesday, February 13, 2007 - 03:48 pm:    You will find many reports of the acoustical effectiveness of glass, but what you are most concerned with must be the entire assembly, as pointed out. There are numerous companies that have tested windows for acoustical performance. In most cases you will find test results reported in STC, even though for your application, OITC (Outdoor Indoor Transmission Class) will be more indicative of the sound attenuation for aircraft noise because it is weighted to transportation noise, not speech as is STC. Test results for glass alone are significantly higher than for a window with the same glass. While lots of windows have been tested acoustically, there is far less testing available on storefront systems. For that reason, I'd stick to a window. In order to properly select acoustical fenestration, you need to know what results you are trying to achieve because the cost escalates as the product's acoustical performance goes up. In your case, the noise sensitivity of the visitors behind the viewing wall is going to be much lower than that of someone asleep in their bedroom under an airport runway. On the otherhand, the exterior (meaning outside the viewing window) noise exposure is likely to be much higher. Your client can give you the noise exposure, but the acceptable noise level inside the viewing area needs to be discussed with the client. In an overly simplified expression, exterior noise, less STC or OITC, equals interior noise level. Here are the principles affecting performance: decoupling (two panes of glass), mass (thicker glass), damping (laminated glass) and flanking paths (perimeter sealing). Insulated glass units perform better than monolithic. Dual glazed units that permit larger air spaces--up to about two inches--will improve performance. Having one pane of laminated glass improves performance, but using two does not increase the performance proportionately. Thicker glass will help, but at increased cost for the glass, and possibly the framing system. Fixed units will perform better than operable ones because they are tighter. You can think of air infiltration as an indicator of acoustic performance. The tighter it is, the more sound is blocked. That principle applies to the frame, and the installation of the window. The non-parallel glass is used to prevent sympathetic vibration internally, but may not be significant in your installation. These are more likely seen in TV studios and the like. A triple-glazed system, with one IG unit and a monolithic "insert," will perform quite will without a lot of heavy glass. This is the basic approach used most of the time for well-performing acoustic exterior windows. Without too much effort, you can reach STC in the range of 40 to 45. For a lot more money, you can get up to about STC 60. In any case, make sure that the detailing of the installation includes lightly packed fiberglass between the frame and the wall, and multiple beads of sealant. I know that St. Cloud Window has done a lot of work with acoustically-rated windows, and is quite knowledgeable. You might try contacting them as a starting point. http://www.stcloudwindow.com/ Anonymous   Posted on Tuesday, February 13, 2007 - 05:25 pm:    Yes! There is such a thing... Northwestern Industries, in Seattle, has a proprietary, laminated "acoustical" glass product complete with numbers and testing... good luck John Bunzick, CCS, CCCA Senior Member Username: bunzick Post Number: 654 Registered: 03-2002 Posted on Tuesday, February 13, 2007 - 05:57 pm:    There is little difference in acoustical performace between glass fabricated with alternative laminating material. Comparing different interlayers would show perhaps 1 dB or so difference. Once in an acoustic assembly, that becomes nearly insignificant compared to the other factors affecting performance. David Axt, AIA, CCS, CSI Senior Member Username: david_axt Post Number: 801 Registered: 03-2002 Posted on Tuesday, February 13, 2007 - 06:49 pm:    BTW, 3 dB is the lowest differential that a human ear can detect.