Acoustic interlayers are laminated between toughening pieces of glass to produce a glazing unit with much improved acoustic performance.
The highly sound insulating PVB interlayers are laminated between glass panels using normal interlayer lamination methods of heat and pressure creating a glass unit with a lower overall Rw value measured in Db.
Every glass thickness and composition vibrates differently at different frequencies meaning that at some frequencies glass sound insulation can be very low. The introduction of an acoustic interlayer into a glass construction reduces this ‘critical frequency’ effect in the glazed element meaning there is no dip in the glass performance for certain sound frequencies and increasing the overall sound insulation for an installation.
These acoustic interlayers can reduce the sound transmission through glass to between 35Db to 49Db depending on glass makeup.
The aim of acoustic insulation glass is not to stop sound coming through the glass units all together, which is nearly impossible, but is to reduce the frequency of noise that can travel through the glass towards 100Hz, making any background noise insignificant enough to be ignored.
The acoustic interlayers used within sound reduction glass are completely transparent and appear as standard laminated glass leaf. The laminated glass panel can then be installed into a double glazed unit for external use, installed into framework or used as internal partitioning elements.
Additional changes to a glass specification such as triple glazing, differing thicknesses of glass and different gas cavity thicknesses can also assist in any acoustic insulation needed.
Acoustic Interlayers are able to be included in almost any glass installation and are available in sizes up to 6m x 3.21m. The minimum size of an acoustic glass unit is 300mm x 300mm.
Other elements of the glass specification such as glass thickness will be determined by the glass installation itself.
See our typical performance table for the acoustic performance of some of the most common glass specifications.
For the same thickness of glass, glass with an acoustic reduction interlayer achieves an average increase, expressed in Rw (BS EN ISO 717), of between 3 dB compared with conventional laminated glass and 5 dB compared with monolithic glass.
Acoustic interlayers overcome the drop in the acoustic insulating performance of glass at the critical frequency, in both single and double glazing. It therefore ensures optimum acoustic performance.
A change in just 2dB in the noise reduction through a piece of glass can half the amount of noticeable sound that can penetrate the glazing.
Building Regulations Part E governs the acoustic insulation values that new buildings in England should adhere to to create comfortable and inviting living and working spaces.
Part E of Building Regs covers:
New walls and floors of new build homes and buildings that are being changed into housing
The Acoustic Insulation between other sleeping areas such as hotel rooms, rooms in a boarding house and student housing.
The acoustic performance of common areas in residential apartment blocks
Acoustic Reduction in school buildings.
Requirement E1 states:
“E1: Protection against sound from other parts of the building and adjoining buildings
“Dwelling-houses, flats and rooms for residential purposes shall be designed and constructed in such a way that they provide reasonable resistance to sound from other parts of the same building and from adjoining buildings.”
Internal and external floors and walls of a new built, purpose built house are recommended to have an Rw value of more than 40 dB.
Reduce Noise Pollution with Glass
More often now buildings are required to achieve specific acoustic insulation performances. Both to create a more comfortable environment within the space for living or working and to reduce noise pollution in congested inner cities.
Specifying the correct acoustic reduction glass within your project can go a long way to creating inviting spaces that are productive working environments, learning spaces and living quarters.
Acceptable sounds levels for rooms in a commercial environment or a school are different to a residential building:
Theatres, Concert Halls, Recording Studios recommended 25-30 dB
Bedrooms, Libraries, Religious Prayer Rooms recommended 25-30 dB
Living Rooms, Classrooms, Lecture Halls, Conference Rooms recommended 30-35 dB
Offices, Courtrooms, Private Work Rooms recommended 40-45 dB
Corridors, Open Offices, Bathrooms, Toilet Rooms, Reception, Lobbies, Shopping recommended 45-55 dB
Kitchens, Shopping, Common Spaces, Dining Halls, Computer Rooms, Workshops recommended 45-55 dB
IQ worked on the glazing as part of the large revamping project at Somerset House. The plan was to change the listed 16th century house into a modern office and events space as well as creating inviting public areas.
Between each floor beautiful light wells create a link between each floor allowing light to travel between the areas of the building. But the open holes between the floors allow noise to travel too.
IQ designed a series of frameless glass inserts for these light wells using an acoustic interlayer within the glazing to reduce noise travel and improve acoustic insulation.