Noise Control

Combating external noise intrusion

Noise reduction units are often requested by customers looking to combat external noise intrusion. Here, it is important to note that the unit alone will reduce noise levels by a certain amount but the whole installation also needs attention to achieve the maximum noise reduction. Things such as trickle vents, poor fitting gaskets, gaps between the frame and wall etc, will all allow noise to pass into the room. The best sound proof units will not prevent these noise ‘leaks’. Customers may complain that the expensive glazing has not made any difference and in a poor frame, it won’t.

Sound reduction is generally classed in 3 ways:

C - This is the mean average sound reduction in decibels (dB) across a range of frequencies.
Rw - This is a weighted decibel reduction incorporating a correction for the human ears’ response to sound. It is more commonly used.
Ctr - This is the decibel reduction for the specific sound frequencies of typical road traffic noise in towns and cities.

Most customers don’t tell us what noise reduction they are after but they will usually be Rw or Ctr (formerly Rtra) values. If we are given a dB reduction target value, we can usually put forward a specific sealed unit make up that will offer the required performance but take into account U-values and glazing possibilities.

Noise reduction in glazing is achieved by altering the frequency of noise travelling through the glass. This is done by varying the thickness of the sealed unit make up.