DIN 4109 also serves, among other things, to determine the required sound insulation level of windows and exterior doors. Basically, the sound insulation value of the outer surface of a room is always evaluated in combination with the sound insulation values of the wall with the sound insulation values of its openings such as windows or doors. For example, the so-called "resulting sound insulation coefficient" R ́w, res is calculated from the individual values (wall, window, door, etc.) for the entire component. In the following, the individual steps for determining the sound insulation value are outlined. Step
- 1: From Table 8 of DIN 4109, the requirements for the airborne sound insulation of external components of the entire wall/window/door component can be taken as a function of the so-called "relevant external noise level" (in dB) or a defined "noise level range" (I to VII). These are the initial values that are usually available to the planner through a sound engineering report.
- Step 2: The resulting sound insulation value taken from Table 8 is R ́w, res is corrected upwards or downwards by +5 dB to -3 dB by the values shown in Table 9 of DIN 4109. The correction value is calculated according to the ratio between the floor area of the room and the external wall area relevant to the room and is intended to take into account the room acoustics.
- Step 3: In the case of a common room geometry (room height approx. 2.50 m, room depth approx. 4.5 m, window area share 10% to 60%), the sound insulation values for the wall and window can be read separately from each other in Table 10 of DIN 4109. These sound insulation measures are met. R ́w form the basis for the selection of suitable windows and doors or the associated walls. If the room geometry does not correspond to the above-mentioned standard values, the required sound insulation values must be calculated in accordance with Section 11, Supplement 1 of DIN 4109. With both approaches, it should be noted that products are often labeled with Rw. The planner should therefore definitely have the R ́w value confirmed by the manufacturer or make a discount according to the definition described above.
In contrast to VDI 2719, the assessment according to DIN 4109 does not differentiate according to living rooms and bedrooms or according to the type of exposure (e.g. road noise). In addition, the daytime exposure is always taken as a starting point, there is no consideration of the exposure at night. In this regard, VDI 2719 is more detailed.
Source: bauwion
