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Balancing Thermal and Acoustic Demands for Total In-Home Comfort

As homeowners seek to make improvements, it’s important to offer solutions that offer a range of high-performance benefits.

Throughout the past couple years, people have been evaluating their homes with a more critical eye and haven’t been shy about making upgrades. 

As it pertains to residential windows, comfort is key. Thermal performance has long been one of the most important performance characteristics of a new window. Another characteristic is acoustic performance and how well a window is able to mitigate sound transmission from outdoor environments into a home. 

Recently, acoustic performance has generated a bit more chatter. Why? Since COVID-19’s onset, millions of people are spending more time at home, and remote work is set to continue. Peace and quiet is perhaps more important than ever before. Meanwhile, developers in the multifamily space are eyeing construction sites near train tracks, elevated lines or major freeways in certain regions of the country, where noise can be irksome unless the proper measures are taken. 

Looking through a window onto a street lined with cars

Delivering the proper balance of thermal and acoustic performance requires evaluating the window system holistically.

This all means those in the fenestration and glass industries might have started to pay closer attention to things like Sound Transmission Class (STC) and Outdoor/Indoor Transmission Class (OITC) ratings, which determine how much sound is transmitted through a window. For fenestration professionals serving the residential market, it’s a burgeoning area of need.

Delivering the proper balance of thermal and acoustic performance requires evaluating the window system holistically and putting together components that will reduce sound transmission while maintaining the thermal benefits. Here are some considerations:

3 Glass and Glazing Configurations

Glass mass, asymmetrical insulating glass and multicavity glazing are all popular and effective choices to improve acoustic performance in fenestration design. 

  1. The glass mass law states that doubling the mass per unit area can improve sound transmission loss by 6 decibels. Therefore, increasing glass thickness on one or more lites of an insulating glass unit can impact acoustics. 
  2. Asymmetrical glazing, or different thicknesses of glass in the same IG, can also improve acoustics by disrupting sound waves. 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. It’s also worth considering skinny or thin triples, a technology that utilizes an ultrathin center lite. Skinny triples can fit within the same frame space as a conventional double-paned unit and don’t create additional weight. Acoustic performance of a skinny triple is comparable to a conventional triple. 
  3. 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 and plies. The laminated glass configurations act as an acoustic shock absorber or dampening material; consult your interlayer supplier for specific design requirements.

High-performance Vinyl

Another area to consider closely is framing and how it contributes to both thermal and acoustic performance. Vinyl has long been the dominant material choice in the residential space, with nearly 80 percent of market share, and inherently demonstrates higher acoustical properties than metallic choices. 

But not all vinyl framing is created equal. Multichambered vinyl extrusions can help dampen noise versus single-chamber options. Further, options that include an integrated insulating core can help drive acoustic performance even higher while helping improve U-factors by as much as 15 percent over hollow vinyl window frames. Along 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. 

Take the Holistic View

These are just a few ways you might improve acoustic performance in windows and doors to deliver on evolving homeowner demands. But the most important thing to remember when designing window and door systems for acoustic performance is to consider the system as a whole. Find the balance—don’t sacrifice one area of performance for another. 

It’s also important to 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 all of these considerations in mind, you’ll be sure to find success in delivering a final product that delivers high performance in all of today’s most important areas.

A Case Study in Acoustic Performance: Combating Highway Noise for a Peaceful Residential Interior

exterior of a multifamily building surrounded by busy interstates


The Modera West LA apartments are flanked by Interstate 405 and the Howard Hughes Parkway. 


To help achieve desired acoustic performance, the complex was built with Silent Guard windows from the Colorado-based Prime Windows. The Silent Guard line, made with Mikron vinyl extrusions from Quanex Building Products, are suitable for a range of residential applications, from single-family homes to multifamily developments like Modera West LA. The units are designed and engineered for enhanced sound reduction via optimized placement and thickness of the glass. 


The inner panel accepts up to ¼-inch laminated glass for use where highest noise levels are encountered, with the ability to achieve a maximum STC rating of 49.


Quanex’s Mikron extrusions further help Silent Guard windows achieve optimal levels of thermal efficiency.  


Eric Thompson

Eric Thompson

Eric Thompson is the national account manager for Quanex. Email him at



Joe Erb

Joe Erb

Joe Erb is commercial sales specialist for Quanex Building Products. For more tips, read Quanex’s blog, In Focus, or contact Erb at