ACOUSTIC

Sound insulation

The need to restrict outside sound is not only a matter of environmental protection but, principally, of well-being. Noise, in addition to generating pollution, can cause illness. Studies show that people who are constantly exposed to continuous noise pollution can suffer from such consequences as stress, nervousness, sleeplessness, poor concentration, and cardiovascular ailments.

This is why, on the one hand, planners and architects are increasingly required to incorporate noise control in building design; on the other hand, the glass industry now turns out an ever increasing number of “e-friendly” basic glass types and specially treated glass products for use in buildings. The most effective way to minimize the effects of outside noise within a building is to insulate its windows. There are generally three options available for maximum sound attenuation:

- Laminated safety glass, which consists of two glass panes with one special acoustic PVB (polyvinyl butyral) interlayer to absorb and, thereby, reduce some of the incident sound energy;

- Secondary glazing, which is a special type of glazing construction in which an additional pane of glass is added to the inside of an existing glazed window; or

- A wider airspace between glass panes.

The panes of glass within an insulating glass unit should vary in thickness, with a minimum 30% difference between them. A combination of all three above options can also be implemented.

Opting for safety, sound reduction, solar energy control, UV control, and durability does not mean sacrificing a building’s harmony or interior! Special color PVB interlayers have recently been launched and are now available for the creative use of architects and designers

Sound Facts
Sound is produced by vibrations. Sound is a physical phenomenon that stimulates our hearing senses. In humans, hearing takes place whenever vibrations of frequencies ranging from 15 hertz to approximately 20,000 hertz reach the inner ear. There are several factors that influence the passage of sound through glass.

Glass Types
The major factor influencing the passage of sound is the glass type. The most common types of glass used are laminated and insulating glass (double-glazed). Laminated glass incorporates a special acoustic PVB interlayer, which absorbs some of the incident sound energy and reduces its passage. This acoustic PVB interlayer can be also utilized to reduce the noise level experienced in cars. Better sound insulation can also be achieved through the use of double-glazed glass. Vacuum-sealed inner spaces, a special selection of glass types, and some gases affect sound insulation and provide acoustic stability. All other types of glass, such as toughened, coated, wired, or patterned glass, behave acoustically in the same way as does comparable standard float glass.

Area Effect
The larger the glazing area is, the greater the amount of acoustic energy that is able to pass through it.

Distance Effect
The more distant the noise source, the greater the decrease in noise level.

Height Effect
In a taller building, the street noise level can be expected to decrease.

Pilkington Optiphon.pdf