Windows are one of the most common home upgrades on consumer wish lists year after year. There are good reasons why—windows can enhance a home’s occupancy comfort via enhanced aesthetics, energy performance and more. That “more” is important in today’s marketplace, as door and window OEMs have the opportunity to further differentiate their product offerings with new technologies. And that brings me to today’s tip:
Consider how acoustic performance can enhance your products.
Acoustic performance has gained increasing attention in recent years. How well a window can mitigate sound transmission from outdoor environments into a home’s interior is critical, and it’s driving greater focus on features like Sound Transmission Class (STC) and Outdoor/Indoor Transmission Class (OITC) ratings, which determine how much sound is transmitted through a window.
There are a number of strategies that OEMs can use to enhance acoustic performance, and, importantly, it requires evaluating the window system holistically and combining components that will deliver on both. For example, your glass and glazing configurations are one of the key areas where acoustic performance can be improved, and there are a few ways it can happen:
- Glass mass, asymmetrical insulating glass (IG) and multicavity glazing are all popular and effective choices to improve acoustic performance in fenestration design. In acoustics, mass law states that doubling the mass per unit area can improve sound transmission loss by 6 decibels (excuse the quick science lesson). Therefore, increasing glass thickness on one or more lites of an IG unit can positively impact acoustics.
- The use of asymmetrical glazing (different thicknesses of glass in the same IG) can disrupt sound waves and further improve acoustic performance. Windowmakers can accomplish this using double- or triple-pane glazing design.
- The use of multicavity glazing will also make significant improvements with thermal performance and occupant comfort. Skinny or thin triples can fit within the same frame space as a conventional double-paned unit and won’t create additional weight. Acoustic performance of a skinny triple is comparable to a conventional triple, but with those extra benefits.
- Finally, laminating glass interlayer options can help address performance requirements in security, impact and acoustics. These interlayer materials can be tuned to meet specific acoustic performance targets using various thicknesses. The laminated glass configurations act as an acoustic shock absorber or dampening material. You can consult your interlayer supplier for specific design requirements.
Outside of IG, another area that can greatly impact thermal and acoustic performance is framing. Industry professionals know that vinyl has long been the dominant material choice in the residential space and inherently demonstrates higher acoustical properties than alternative metallic choices. But not all vinyl framing choices offer the same performance benefits.
Innovative multichambered vinyl extrusions can help dampen noise more than single-chamber options. Further, options that include an integrated insulating core can drive acoustic performance even higher while helping improve U-factors by as much as 15% over hollow vinyl window frames. Paired with high-performing warm-edge spacer systems and sealant materials, this kind of framing technology can help window manufacturers deliver outstanding performance and meet several demands at once.
Ultimately, the most important point to remember when designing door and window systems for acoustic performance is to consider the entire system. Find the balance. Don’t sacrifice one area of performance for another. Work with your component suppliers and an acoustic engineer to select the most effective solutions. In acoustic design, the system’s performance is only as good as the weakest link. Physical testing is the only way you will truly know the impact of the materials and the assembly methods for your system. With these considerations in mind, you’ll be on your way to finding success in delivering a final product that delivers high performance where it’s wanted most.
John Ryba is technical services director for Quanex
Excellent and informative article John!