Noise is a common nuisance that can easily penetrate our environments, from the occasional emergency siren disrupting your sleep to the constant traffic noise while you work. Research has shown that noise can negatively impact your health and overall quality of life. By enhancing sound insulation, glass can help reduce unwanted sounds, transforming your buildings into quiet, serene spaces.

What is acoustic glass?

In general, the thicker or heavier the glass, the greater the noise reduction. Therefore, sound reduction efficiency increases as glass thickness increases. However, the use of laminated glass provides further benefits of acoustic insulation. When replacing a single glass pane with a laminated pane, with the same overall thickness, the sound insulation is significantly improved.

How is acoustic glass made and how does it work?

Laminated glass consists of two or more layers of glass that are permanently bonded together with one or more polymer interlayers using heat and pressure. Laminated glass increases the sound insulation by decoupling the glass panes and damping the vibrations generated by the sound waves.

What are the benefits of laminated acoustic glass?

Noise reduction

The primary benefit of acoustic glass is its effectiveness in reducing sound transmission. It helps to reduce external noises such as traffic, construction, and street sounds, while also minimizing internal noise within a building. This results in a quiet and serene indoor environment, which can improve comfort, productivity, and focus.

Safety and security

When subjected to sufficient impact force, laminated glass might break. However, the glass fragments tend to adhere to the plastic interlayer, helping to reduce the risk of injury due to fragments of broken glass. Specific laminated glass make-ups can be used for applications that require anti-intrusion or forced-entry security, as well as for ballistic and blast mitigation, or hurricane resistance.

UV protection

Laminated glass can absorb up to 99% of harmful UV rays, which are responsible for up to 50% of interior surfaces fading. This protection helps keep interior surfaces and furniture looking like new longer.

Energy efficiency

When combined with high-performance or low-E coatings, laminated glass can help improve the energy efficiency of buildings by providing thermal insulation and/or solar control properties.

How is acoustic performance measured?

Acoustic rating can be used to measure sound insulation of building elements and varies depending on the region of the world. For example, Rw is used in Europe while OITC and STC ratings are used in North America. Other regions may use one option or the other.

Weighted Sound Reduction Index (Rw)

The most commonly used measure in Europe is the average noise reduction factor, also known as Rw. We apply additional correction factors to the Rw that represent the deviations of sound insulation depending on the sound source.

The Rw represents the overall index (dB), the C represents the correction factor for higher frequencies and the Ctr represents the correction factor for lower frequencies (typical traffic noise).

Depending on the noise source, the correct glazing should be selected by considering if it’s exposed to low frequencies or high frequencies.

In this example, the reduction factor is –1 db, which gives a total acoustic value of 41 dB, and the reduction factor Ctr is –5 dB which gives a total acoustic value of 37 dB. 

Acoustic estimation tool

The sound control properties of glazing can be estimated using computer models. Different software exists for estimating the acoustic performance of different types of glazing.

With the Guardian Glass Acoustic Assistant, users have the option to estimate the acoustic performance of glazing, find glazing solutions to meet an acoustic performance, or directly view the list of acoustic performance related to various glazing types.

The estimation of acoustic performance is based on component-similarity assumptions which are derived from measured data and interpolation. In this approach, it was possible to expand the database of values from test certificates. It’s important to remember that currently there are no standards that describe how to estimate the acoustic ratings for glazing.

What other elements can improve the acoustic performance of an Insulating Glass Unit (IGU)?

Many parameters influence the overall acoustic performance of a building envelope such as the framing system, sealing, installation of glazing and others. Regarding the glazing, the most important to mention, in addition to the glass thickness and the use of laminated glass are:

The symmetry of the glazing composition

An option to optimize the acoustic performance of glazing is to use different glass thicknesses in a glazing composition. The different thickness of each glass pane in a glazing unit minimizes resonance effects due to the thickness differences of the glass components.

The air space of the insulating glass unit

The interspace of insulating glass units muffles the vibrations from the outer pane before they reach the inner second pane. Therefore, the greater the interspace, the better the noise reduction. Bear in mind that the larger air space increases the overall glazing thickness and impacts thermal insulation performance.

It is important to note that heat-treatment, coatings, and ceramic frit DO NOT impact the final acoustic estimation.

Text taken from: https://www.guardianglass.com/