Soundproof windows: how acoustic glazing reduces noise

How does soundproof glazing help reduce noise? Learn about this practical and versatile product and how it works.

Glass and glazing systems are multi-functional products. A glazing system – whether for a curtain wall, window, door or screen – enhances thermal efficiency, maximises natural light, increases building safety and provides acoustic insulation.

In other words, glazing systems help make homes and business premises more environmentally friendly and more people-friendly. Not bad for an assembly of glass and steel or aluminium.

Soundproof glazing systems are specialised windows and window frames designed to reduce noise pollution by between 40 decibels and 50 decibels.

They typically feature acoustic laminated glass, although other configurations of glass exist. These include double-glazed units and even thick single panes.

Laminated acoustic glazing, however, uses a polyvinyl butyral (PVB) interlayer to dampen vibrations. This helps maintain a calm and quiet environment indoors. Furthermore, if the building itself is noisy, acoustic glazing helps stop noise pollution from travelling in the opposite direction.

Soundproof glazing can reduce external pollution by up to 95%. This makes it a popular choice for homes and offices near busy roads, railways and airports.

How does acoustic glazing reduce noise?

Acoustic glazing reduces noise in several ways. These include the use of laminated acoustic glass, panes of different thicknesses, wide air gaps and suitable framing systems.

Laminated glass

Laminated glass consists of two (or more) panes of glass bonded with a plastic interlayer. This interlayer dampens the sound and absorbs vibrations.

Varying thicknesses

By using panes of different thicknesses, acoustic glazing disrupts a wider range of sound frequencies. This arrangement is often found in acoustic double glazing.

Wide air gaps

The acoustic performance of double glazing can be improved by increasing the space between the panes and filling it with krypton or argon.

Framing systems

It's not just the glass itself that matters. The frames, too, must be built for soundproofing. An acoustic glazing system will consist of specialist acoustic glass alongside a high-quality, lab-tested frame.

Are all soundproof windows made from laminated glass?

Sometimes, the phrase "acoustic glazing" is used synonymously with "laminated acoustic glass". Not all acoustic glass, however, is made from laminated glass.

Laminated glass is often the product of choice. That's partly because its thickness makes it particularly good at dampening sound. And it's partly because it allows architects, designers and building occupants to take advantage of the many other benefits of laminated glass.

This is all down to how laminated glass is manufactured. It consists of two panes with a special sound-dampening interlayer.

Laminated glass is around six times tougher than ordinary annealed glass. This makes it exceptionally hard to break. Moreover, it's designed to hold together under impact, limiting the danger of falling shards in the event of a fracture.

Acoustic glazing can also be an insulated glazing unit (IGU). This is a double- or triple-glazed unit, sometimes made with laminated glass. The sheets have different thicknesses to tackle different sound frequencies.

In double-glazed units, a wider gap between the two panes can improve acoustic performance – especially when the gap is filled with a dense, inert gas like krypton or argon.

Finally, acoustic glazing can be a single thick sheet of standard glass. This kind of glass – sometimes known as "monolithic glass" – is typically less effective at blocking low-frequency sounds than specialised laminated acoustic glass or a laminated IGU.

How is the performance of acoustic glazing measured?

Acoustic glazing performance is measured in decibels (dB) using the weighted sound reduction index. This quantifies how much noise a window reduces. Higher values point to superior sound insulation.

Soundproof windows are tested in laboratory settings and are often tested for low-frequency noises such as traffic. You should always work with a glass processor with quality assurance credentials and whose products carry the Kitemark seal and meet relevant BS EN standards.

What are the alternatives to acoustic glazing?

Acoustic glazing is the best way to reduce noise pollution in a building while maintaining visibility and natural light.

In some cases, however, architects and designers use alternatives. These fall into two categories: secondary glazing and window inserts.

Secondary glazing

Secondary glazing consists of a separate, independent pane of glass inside an existing window. This means the original doesn't have to be removed and replaced. A high-quality secondary glazing unit with a wide air gap can make a big difference to noise levels.

Window inserts

Window inserts are clear acrylic panels that fit inside the existing frame to create an additional airtight barrier. As with secondary glazing, window inserts mean original glazing can stay in place.

While they're cheaper and more DIY-friendly, window inserts aren't nearly as effective as secondary glazing or specialised acoustic glazing. This is worth bearing in mind when sourcing materials for your building project.

What is the best thickness for acoustic glass?

Acoustic glazing comes in different sizes. The panes should be between 6mm and 12mm thick. In the case of double-glazed units, panes of different thicknesses can be used for maximum frequency disruption.

Is acoustic glass as clear as normal glass?

One of the great things about modern glass products is that they offer specialist performance without compromising clarity. In the case of acoustic glazing, interlayers are highly transparent and don't affect overall visibility.

How we can help

At Wrightstyle, we provide architects, designers, specifiers and contractors in a range of industries with high-quality, high-performance glazing systems for curtain walls, doors, windows and screens.

Our product portfolio includes acoustic glazing systems specialised for superior noise reduction. This covers our whole range of products from curtain walls to doors, windows and screens. It also includes fire-rated and blast-resistant products.

All our glazing systems have been tested to meet relevant industry standards – and they're all made of steel, taking advantage of the material's high performance levels.

Are you looking for an acoustic glazing system that meets and exceeds all relevant performance standards? Get in touch with Wrightstyle today for comprehensive product advice.