Clearview 225 - August 2020 | Page 37

Aluminium Extra 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 to other floors, the reason for this is that the box will allow sound to travel unless it is broken per floor. Provisions can be incorporated such as an acoustic insert, multiple transoms can also be used to allow the sound to dissipate. Careful design is required to allow movement of the curtain wall system whilst ensuring that sound does not travel between compartments or floors of the building. Curtain wall also has the ability to transmit impact sound across compartments as well as airborne sound and selecting suitable methods of construction will improve attenuation. Whilst there is no one fix for all conditions, our design team in London and at our head office here in Altrincham can offer advice on how to tackle sound attenuation in both new and existing buildings. With one of the widest ranges of aluminium systems available in the UK we can offer you a bespoke design to meet both thermal and sound attenuation requirements. Since setting up the Aluprof Project Office at the Business Design Centre in London, the company has rapidly grown their specification influence in the UK with their high performance architectural aluminium systems. Further expansion of the companies headquarters in Altrincham now provides specifiers with meeting facilities and an extensive showroom of commercial systems to view. With overseas growth across Europe spreading into the Middle East and firm roots already in the East of the USA, the company is becoming a global player in facade supply. Further information is available on the companies website at aluprof.co.uk or direct from their UK office in Altrincham on 0161 941 4005. CLEARVIEW-UK.COM » AUG 2020 » 37