Sound insulation
About Sound Insulation
In recent years, based on our experience, we have been placing increasing emphasis on the sound insulation value of windows and doors, in addition to their thermal insulation value. These parameters were previously only considered in large projects and office building constructions, but nowadays, sound insulation plays a significant role even when replacing windows and doors in residential homes.
The higher the dB value of the glass, the more effectively the insulating glass structure prevents the transmission of sound. The symbol for sound insulation is Rw, its unit of measurement is the decibel, symbolized by dB. To provide a clearer picture of what different values mean, we have gathered the typical dB values of some commonly known sound sources:
Non-disturbing sounds
- Rain: 20 dB
- Whispering: 30 dB
- Normal radio: 40-50 dB
- Normal conversation: 60 dB
Disturbing sounds
- Telephone ringing, "typewriter": 70 dB
- Busy urban road: 80 dB
- Pneumatic jackhammer: 90-110 dB
Painful sounds
- Helicopter: 120 dB
- Jet aircraft: 140 dB
How can we protect ourselves against the above noises?
Noise source that you want to protect yourself from: 60 dB
- ⇒ You don't want noise in your environment to exceed 20 dB
- ⇒ Choose glass with a 40 dB rating
The perception of dB changes for the human ear approximately:
- +1 dB, barely noticeable
- +3 dB, noticeable
- +5 dB, we feel a significant difference
- +10 dB, we perceive the noise level as doubled
How Can We Increase the Sound Insulation Value of Our Glass?
- For standard thermal insulating glass structure (4 - 16 - 4), we use 6 mm glass instead of 4 mm on the side facing the noise source (this can increase the Rw value by 5 dB).
- Application of Soundproof foil: The noise protection film is a special soundproofing foil usually made of polyester, and is used between the layers of multi-layer glazing, on the outer and/or inner sides of the layers. The foil is not visible to the naked eye, which is not surprising since it is transparent and barely 1 mm thick.
To further increase sound insulation, the number of foils between the glass layers and the thickness of the glass can also be increased!
Meeting unique needs requires considering unique aspects!
The Rw value always indicates the so-called weighted-average sound insulation value of the structure. This means that the structure is tested in 16 different frequency ranges between 100 and 3,200 Hz. The obtained results are averaged by weighting - giving more consideration to the more characteristic frequencies and less to the less characteristic ones - resulting in the weighted-average sound insulation value of the structure, Rw.
In addition to the weighted sound insulation, the Rw+Ctr value of the structures is also commonly indicated. The "tr" comes from the English word "traffic". The Ctr value is typically lower than the weighted sound insulation value.
This value shows the sound insulation of the structure in the frequency range that typically originates from traffic noise and street noise.
Noise Level Reduction
If we have the opportunity to think and plan at an early stage, we should not ignore the fact that the absorbed noise decreases proportionally with the distance from the noise source!
In practice, this means:
- At a distance of 5 meters from the noise source, the measured data,
- At a distance of 10 meters from the noise source, the noise level decreases by 3 dB,
- At a distance of 20 meters from the noise source, the noise level decreases by 6 dB,
- At a distance of 40 meters from the noise source, the noise level decreases by 9 dB,
- At a distance of 80 meters from the noise source, the noise level decreases by 12 dB,
- At a distance of 100 meters from the noise source, the noise level decreases by 15 dB.
In addition, it is also possible to effectively protect against specific noise sources, but for this, we need to know the approximate frequency of the noise source. This is important to find the best solution in the given frequency range, not necessarily in the weighted average.
