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Technical Review Middle East - Issue Two 2013
Glass
Sound sense in glazing today Providing a range of noise control levels is one of the benefits of using modern high-performance glass. By day and night the Gulf is now a glittering showcase of what the global industry can do.
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HE MAIN REQUIREMENT of architectural glass is that it allows natural light efficiently into a building, while acting as a robust cladding material at the same time. Strength, transmittance, reflectance and accurate colour rendering ensure those qualities. However modern highperformance material can perform several other functions at the same time. For example, it can provide a (substantial) measure of solar control, a vital quality here in the Middle East where sheet glass in suitable enclosures is a vital component of nearly all building service (incorporating air condition) systems.
Selective It can enhance the security and fire safety of the building, deterring intruders (including unwanted elements of the weather) and providing protection for a specified amount of time, too. By selective shading and control of direct solar energy transmittance, reflectance and absorptance today’s highspec glass can provide a major thermal insulation function, effectively keeping out unwanted solar insolation. If suitably coated it can now keep itself clean, too. And of course it comprises a key feature of the aesthetic design of the building structure itself – high-performance glass now provides most of the ‘wow’ factor at steel-framed structures, both large and small, throughout the Gulf, especially www.technicalreview.me
Modern, high-performance material can perform several functions at the same time
when it is combined with imaginative lighting and viewed at night. And modern high-performance laminated safety glass such as OptiphonTM from Pilkington (Nippon Sheet Glass group) can provide a high level of insulation from outdoor sources of noise, such as heavy road traffic, and nearby indoor sources, e.g. the low-, medium- or high-frequency hum from industrial processing lines or the permanent bass throb from a generator.
Incursive noise When designing any glass component or complete installation (‘unit’) for the control of sound it is important to inform the architect or other specifier precisely what the origin of the noise is. Typical sources plaguing building occupants in the Gulf today include urban road traffic, especially where it is moving at high speed or at traffic control points, gas turbine-powered aircraft or industrial installations, and the irregular incursion of sound from a noisy domestic neighbour.
Today’s high-spec glass can provide a major thermal insulation function
Some tenants also complain about the incursive noise of children playing – and of course the evening emanations from entertainment and other adult social facilities are a legendary cause of complaint all over the world.
Suitable material All these sounds should be measured and analysed as spectrums or sound profiles by an audio specialist before ever the architect starts to put hand to mouse. A suitable material can then be specified, along with the enclosure in which the glass panel is to be carried. Key considerations when specifying a suitable material are the mass of the material itself, in other words not just its density and thickness (and therefore weight), but also its crystalline structure; the amount of space between panes in a two or three-fold sandwich structure (universal these days); and how that space is filled (is it a vacuum or a purposedesigned gas? As well as positioning the level of noisereducing performance of the resulting panel will depend on all of these factors, resulting in the formulation of a soundreduction index. A level of impact- and fire safetyprotection – also index defined - is usually provided by the designer at the same stage, leading up to a complete specification which is provided to both the supplier and the client. In the case of a