ALUPROF
Sound attenuation is also a little more complex in application
and specifiers need to be aware that a change in window size can
have an impact on ‘expected’ attenuation levels. Furthermore,
attenuation is not linear, transmission of frequencies may mean
that at one level of frequency, in a given window specification,
sound is well attenuated whilst at another frequency, sound
attenuation will be less. Knowing what frequencies to specify too is
crucial in getting the installation best specified for the client.
Whilst ensuring airtight window systems to increase sound
attenuation, these can be provided with ‘glazed-in’ or ‘in-frame’
acoustic ventilators which consist of baffles and acoustic
absorbing materials to allow ventilation but with attenuated
noise transmission. Acoustic ventilators may not offer the level of
attenuation required and this is where an alternative mechanical
ventilation provision should be considered. Depending of the
configuration and specification of the design of windows or curtain
wall required, our Aluprof design team can assist in the best
options to be specified.
Where prime windows need to remain in place, for example in
listed facades, then the option to install a secondary window
system will offer a good solution. Using spacings of 100mm to
150mm between these windows including the inside reveal lined
with acoustic absorbing material will offer very high levels of sound
attenuation.
Flanking sound transmission is quite a talking point at the moment
in the industry. On almost every acoustic assessment when there
is a continuous curtain wall, sound can travel through the facade
So, the more airtight the window, the greater the sound reduction. to other floors, the reason for this is that the box will allow sound to
Typically a well sealed single glazed window will offer a -30dB travel unless it is broken per floor. Provisions can be incorporated
reduction in sound transmission, or what is known as ‘attenuation’. such as an acoustic insert, multiple transoms can also be used
In busy built up areas single glazing is now seen as inadequate. to allow the sound to dissipate. Careful design is required to allow
movement of the curtain wall system whilst ensuring that sound
For every 10dB reduction in the noise level achieved, the human does not travel between compartments or floors of the building.
ear perceives this as halving the volume. Curtain wall also has the ability to transmit impact sound across
compartments as well as airborne sound and selecting suitable
Glazing plays the biggest part in sound attenuation, double glazing
methods of construction will improve attenuation.
helps, especially if the glass used is of differing thickness. Most
materials at a given thickness will ‘resonate’ at certain frequencies Whilst there is no one fix for all conditions, our design team in
and allow some of those frequencies through, using a different London and at our head office here in Altrincham can offer advice
thickness ensures what passes through one will not pass through on how to tackle sound attenuation in both new and existing
the other. A well designed triple glazed unit with differing air spaces buildings. With one of the widest ranges of aluminium systems
and glass thickness, will perform even better. Acoustic laminates available in the UK we can offer you a bespoke design to meet both
used in laminated glass are specially designed to minimise sound thermal and sound attenuation requirements.
transmission and a well designed unit can achieve up to -45dB
sound attenuation.
Since setting up the Aluprof Project Office at the Business
Design Centre in London, the company has rapidly grown their
The use of triple seals further improve sound reduction and high specification influence in the UK with their high performance
thermal performance systems with wide high performance centre architectural aluminium systems. Further expansion of the
seals with further attenuate sound around a high performance companies headquarters in Altrincham now provides specifiers
glazed unit. with meeting facilities and an extensive showroom of commercial
systems to view. With overseas growth across Europe spreading
Regarding specification, Building Regulations, Part E, ‘Resistance into the Middle East and firm roots already in the East of the USA,
to the passage of sound’ should be consulted as well as a number the company is becoming a global player in facade supply. Further
of standards that are currently in place. Depending on the building information is available on the companies website at aluprof.co.uk
there are also specific and differing requirements laid down for the or direct from their UK office in Altrincham on 0161 941 4005.
likes schools, hospitals and offices, to name a few. Some company
chains, such as Premier Inn, have their own acoustic requirements. www.aluprof.co.uk
When specifying BREEAM rated projects, there are points than can [email protected]
also be awarded for compliance in certain circumstances. 0161 941 4005
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