Home Engineering Building Acoustics
Sound Insulation to the Exterior
The fagade will be dimensioned on the shortest room, in our case, 2.50 m. Let’s consider a 1.45 x 1.40 m2 window. Under these conditions, the window will have to feature a sound
Figure 17.4 Schematic cross section of refurbished building with added-on glazed curtain facade wall.
reduction index Rw + Ctr of 34 dB minimum inside a 15 cm thick reinforced concrete wall featuring a sound reduction index value Rw + Ctr of 47 dB.
Should a light fagade type be used, a global sound reduction index value Rw + Ctr of 45 dB minimum will be needed.
Note: In addition to this requirement, the fagade must enable the possibility of correctly separating different dwellings in compliance with the targeted legal sound insulation value. This will lead to a fagade featuring a flanking sound insulation value Dncw + C of 60 dB minimum.
In addition, should the ventilation system be return air only, one should take into account the air inlets that will be located either in the fagade main walls or in the window frame. The requirement for one such inlet will be Dnecw of 38 dB.
Note: Under some regulations and bylaws it may not be permitted to use a standard fagade when exposed to significant transportation traffic noise (e.g., ); it will then be necessary to introduce a curtain wall in front of the original fagade (cf. Figure 17.4).
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