ISO 12354-4:2017 pdf free

ISO 12354-4:2017 pdf free.Building acoustics – Estimation of acoustic performance of buildings from the performance of elements
The model also gives indications of the directivity correction that can be expected for various types of elements. The inside sound pressure level will normally be the equivalent sound pressure level over a specified period according to the relevant requirements. However, other types of levels can also be used, for instance the maximum level. The calculation of the inside sound pressure level is outside the scope of this document.
The total attenuation Atot due to propagation effects, necessary for the prediction of the sound pressure level at the reception point, can be estimated according to available methods for outdoor propagation,based on a point source approach. The calculation of these propagation effects is outside the scope of this document.
NOTE One such method is given in ISO 9613-2, where the total attenuation is indicated as A. The total attenuation follows from the addition of the attenuation due to various propagation effects, such as geometrical divergence, air absorption, ground effect, creening, etc.However, for simple propagation conditions an approach is given for the estimation of the sound pressure level in Annex E.
Although large, homogeneous building elements, e.g. a complete side wall, can have specific radiation patterns, favouring certain directions; these effects are not taken into account in the model.The possible contribution of structure-borne sound by machinery in the building is not included in the model, although an approximate approach is indicated in Annex C.
The accuracy of the prediction by the model presented depends on many factors: the accuracy of the input data, the fitting of the situation into the model, the type of elements involved, the geometry of the situation, the type of quantity to be predicted and the workmanship. It is therefore not possible to specify the accuracy in general for all types of situations and applications. Data on the accuracy will have to be gathered in the future by comparing the results of the model with a variety of field situations.
In applying the predictions it is advisable to vary the input data, especially in complicated situations and with rare elements with questionable input data. The resulting variation in the results gives an impression of the expected accuracy for these situations assuming similar workmanship.ISO 12354-4 pdf download.