Last update: 19.08.2019
Sound control
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Acoustic performance of glazing

Guardian has certified the acoustic performance of a variety of single and insulating glass build ups consisting of Guardian float glass, LamiGlass or LamiGlass Acoustic.

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Many parameters influence the acoustic performance of glazing.

Optimisation of sound insulation

 

Weight of the glass panes

It generally follows that the thicker the pane per surface unit, the greater the noise reduction. Therefore, insulation efficiency increases as glass thickness increases.
 

Insulating performance

 

Insulating glass build-up

Double or triple glazed units are a mass-spring-mass system. Both outer panes (masses) are separated from each other by the air or gas that fills the interspace. The sound is almost completely transmitted by resonance from pane 1 to pane 2 if both have the same thickness. Therefore, the improvement from a single glass to an insulating glass consisting of glass panes of the same thickness is marginal.

Insulating glass as mass-spring-mass system

 

The interspace muffles the vibrations from the outer pane before they reach the inner second pane, with the rule being the greater the interspace, the more effective the noise reduction. But this is only possible to a limited degree, as a large interspace reduces the thermal insulation and increases the climatic load. 

Influence of insulating glass interspace


In order to optimise the acoustic performance of glazing, the insulating glass composition should be as asymmetrical as possible. This minimises resonance effects due to the thickness differences of the glass components.
 

Insulating glass constructions

 

Gas filling

In the past, the filling gas was also considered as a method of improving the acoustic performance of insulating glass units. Special heavy gas mixtures using SF6 were used for high sound insulation requirements. However, as these gases were recognised as detrimental to the environment, since 2007 they are forbidden for use in windows in the EU. 


According to the EN 12758, measured acoustic performance data based on argon or air gas fillings can be used for the same glass build ups filled with both argon or air. From 2018, the preliminary version of this standard also takes krypton as a filling gas into these considerations.


The differences regarding thermal insulation of these mentioned filling gases need to be considered.
 

Stiffness of the glazing

Stiffness of the glazing (decoupling of single glass elements)

The noise reducing effect of thicker, heavier glass can be further optimised by laminated glass using a flexible interlayer (PVB) to connect two single panes of glass. With this solution, the thickness and weight per unit area remain the same. The pane, however, becomes “softer”, therefore increasing its sound insulation by decoupling and damping the vibrations of the glass panes generated by the sound waves.


Special acoustic PVB interlayers are available for further improving the capabilities of sound insulating glass. It consists of a multi-layer build up using standard PVB with a special soft acoustic core.

Decoupling of single panesStiffness of the glazing

This composition enables safety and security performance to be maintained, while significantly improving the acoustic insulation. 

Comparison Lamiglass Acoustic vs. Standard


The acoustic performance of laminated glass (particularly with soft acoustic interlayers) depends strongly on the environmental temperatures. The PVB interlayer becomes very stiff at low temperatures and soft at higher temperatures. The stiffer the PVB, the worse the sound damping and decoupling behaviour. Laboratory measurements for Rw according to the EN 10140-2 standard require a sample temperature of 20°C ± 3°C. Measurements on the building site according to EN 140-5 (R‘w) are not regulated in terms of temperatures and glass dimensions. Obviously, this can lead to significant differences in results compared to certified acoustic performance values based on standardised lab measurements.
 

Stiffness of the glazing

 

Guardian Sound Reduction glass

Guardian has certified the acoustic performance of a variety of single and insulating glass build ups consisting of Guardian float glass, LamiGlass or LamiGlass Acoustic.

 
In addition, Guardian provides the „Acoustic Assistant“ estimation software tool, which enables the acoustic performance of glazing to be estimated based on existing certified data and special modelling. The software is available online Glass Analytics Tool