Acoustic Windows: Are They Your Key to Quiet?

Nowadays, a lot of people take double glazing for granted. Yet, just a generation ago, this was a relatively new invention that solved a lot of people’s sound insulation and warmth problems. Double glazing meant no scraping ice from the window panes in the depth of winter and a much quieter life than in previous generations.

However, as times move on, people want and expect more and more from their windows and doors. And while triple glazed windows have been around homes near airports or in colder places like Sweden where they first appeared, there is something much more noise reducing: acoustic glass.

With the world’s population soaring, people are moving closer and closer together. There are fewer rural homes and more people living closer to industrial estates, busy roads, motorways, airports, and train lines. With this comes a lot more noise pollution.

Noise pollution is a problem that affects many people both at home and at work. As well as being distracting, it can cause people serious distress. After a long day at work, most people want a quiet place to relax at home without the added background noise of the nearby train line, noisy road or industrial yard.

Or, as many of us now do, if you’re working from home, you want a quiet environment in which to do so. For these reasons, there has been an increase in people looking to install acoustic windows to replace their existing windows and double glazing.

What is acoustic glass?

Acoustic glazing is a special type of noise reduction glass that can be installed in offices and homes. These noise reduction windows are constructed of two (or more) laminated glass panes. The panes are laminated with polyvinyl butyral (PVB) and are bonded with the same material. Polyvinyl Butyral can reduce noise and soundproof windows.

Unlike double or triple glazing, acoustic windows and doors appear to have one pane of glass.

What is polyvinyl butyral (PVB)?

Polyvinyl Butyral (PVB) is a type of resin that is used for its ability to form a strong bond while maintaining optical clarity. What’s more, it’s flexible, tough, and will adhere to a variety of surfaces. PVB is made by reacting polyvinyl alcohol with butyraldehyde.

The most common applications for PVB are in laminated safety glass and windscreens as well as acoustic windows.

PVB has excellent capabilities of reducing noise levels inside a building without reducing the light transmittance or clarity of the window. What’s more, this glass meets all of a home or office’s interior sound insulation needs.

What are Acoustic Windows?

You might often hear people talk of acoustic glazing or an acoustic window. Essentially, an acoustic window is a noise reduction window that is made from at least two pieces of noise reduction glass that have been bonded with polyvinyl butyral (PVB).

It is possible to buy new windows with acoustic glazing already installed or you can upgrade your existing windows and standard double glazing with this energy efficient secondary glazing.

The amount of noise reduction achieved is determined by the glass thickness. The thicker that glass panes, the more sound insulation and less sound leakage there’ll be.

Acoustic windows are also safety. As well as preventing noise intrusion, they are a toughened glass that performs well under impact.

If a heavy force or heavy object comes into contact with an acoustic window, the glass might fracture but no loose pieces will escape. This is because all of the broken glass fragments will be bonded to the interlayer of PVB, which means glass shards can’t escape. What’s more, because of the glass strength, acoustic windows are a deterrent to any would-be burglars who will have a tough job breaking through them.

All in all, acoustic windows are excellent at keeping a business or home secure, warm and protected from external noise.

Acoustic glass: how does it work?

Many people want to know how acoustic glazing actually works. Essentially, the laminated glass layer and PVB interlayer reflects any noise back to its source. These windows also reduce noise by absorbing the sound energy in the glass.

The acoustic performance of the glass can be increased with thicker panes. Not only does a thicker pane of glass have a greater noise reducing effect, but it also improves the insulating properties of the windows.

To summarize, acoustic glazed windows work by reflecting and dissipating sound waves that reach the glass. The level of noise reduction is determined by:

• the glass pane thickness
• the strong hydrocarbon bond interlayer
• spacing between panes

Glass pane thickness

The thicker the panes of glass used, the greater the noise reduction.

The interlayer

A strong hydrocarbon bond interlayer dampens soundwaves and increases their noise reducing capabilities without impacting thermal efficiency or light clarity.

Spacing between panes

It is possible to increase noise reduction significantly with larger spacing between glass panes.

To prevent sound vibrations penetrating further, the space between panes can be filled with a heavy inert gas like argon gas. This will make costs rise, however.

It is possible to get a single pane of acoustic glass too.

The differences between double glazed windows and acoustic windows

Glass, by its nature, is a poor conductor. It doesn’t easily absorb sound. This means that outside noise can enter the office or home very easily. Pre-1980s, most homes had single glazing, which meant a lot of noise got into the property. Double glazing started to become more popular due to its soundproofing and insulating abilities.

The difference between a double glazed window and an acoustic window is that the noise reduction of a double glazed unit works by reflecting noise rather than absorbing it. An acoustic window is much more effective at noise reduction because it absorbs the noise.

One other difference between the two is that of government support. There are a few double glazing grants that can help you improve your home from single glazing but they do not apply to acoustic windows.

The Benefits of Acoustic Windows and Doors

There are numerous benefits to having acoustic windows rather than a double glazed unit or a triple glazed unit.

• Outside noise is reduced. There is less noise entering the office or home as sound transmittance is reduced significantly.
• Reduction in UV radiation. Acoustic glass can reduce the amount of UV radiation entering the space by around 99% – a reduction of 320 to 380 nanometres.
• Good for skylights and roof glazing. In roofing, these glazed units will improve insulation and provide noise reduction from rainfall.
• Excellent for meeting rooms and office partitions. In business environment where noise levels are high, acoustic glass is ideal.
• More safety. Acoustic windows are shatterproof and much safer than ordinary glass. If a window is broken, all broken pieces stay bonded to the interlayer. They’re also notoriously difficult to break by would-be intruders.
• Protection. With certain arrangements, acoustic glass can be used to protect against explosions and firearms.
• Increased thermal values. As well as their soundproofing qualities, acoustic windows reduce how much heat escapes through the window. This reduction in heat loss can reduce energy bills.
• New windows come in a variety of window styles. You can get noise reducing acoustic glass for casement windows, leaded windows, windows with Georgian bars, a triple glazed unit, and as secondary glazing for sash windows. You can even get a front door window pane with acoustic glass as well as coloured glass designs.

Final thoughts on acoustic glass

To summarize, as well as being excellent with noise reduction, acoustic glass increases a window’s strength dramatically. It also improves the window’s energy efficiency. Reducing noise in the home has many benefits. These include positive effects on wellbeing, improved sleep, better relaxation, and thus, people report having more energy.

An acoustic window works by reducing how much noise can enter the property by its two panes of PVB laminated glass and a PVB interlayer. Polyvinyl butyral has excellent sound absorbing properties and doesn’t compromise or reduce the light transmittance or clarity of the window. There are also additional security, safety and thermal benefits with improved energy efficiency.

Acoustic glass can also be used in secondary glazing for sash windows or on a current window to increase their acoustic performance.

Frequently Asked Questions

Does triple glazing have more soundproofing capabilities compared to acoustic windows?

Although triple glazing is an improvement on noise reduction compared to double glazing thanks to the extra pane. The glass in the windows are solid and rigid, making them poor conductors. They are not capable of absorbing any external noise. Acoustic glass, however, can absorb noise.

There is some evidence that triple glazing can increase the penetration of sound as this third pane can work as an extra material that transmits sound waves.

What other ways can a business or home be soundproofed?

Other ways to soundproof a property include:

• Installing thick curtains – but this will only help for night time noise.
• Improving wall insulation as this will increase the wall’s mass and will help dampen noise that travels through walls.
• Using draught excluders on doors can minimize entering sounds.
• Using acoustic wedge panels.
• Having thicker carpets that will absorb sound and reduce sound vibrations.
• Avoid installing trickle vents as these will counteract the benefits of the glass.