Like many other premises in the tertiary sector, restaurants in enterprises (canteens) are spaces of everyday life in which the reverberation should be limited to control ambient sound levels, for the well being of occupants that are both users and service staff. It is often necessary to use in such cases special equipment in terms of architectural acoustics to ensure the habitability requirements for those spaces to which are applicable regulatory provisions related to noise limitation in offices and associated areas (including specific technical requirements for restaurants) .
ITS has participated in the improvement of the acoustic ambiance of a restaurant in an enterprise / a cafeteria by the means of perfectly matched acoustical screens (absorbing claustras) and absorbing wall lining near Bourg en Bresse (France, Rhône-Alpes region, Ain county), in a context where on-site measurements have shown that the values of reverberation time before soundproofing were not conform to limiting values to be met for such a premise with respect to its use and to its volume.
Given the annoyance felt by the occupants that led the enterprise management to consider soundproofing works, a reduction of the reverberation time has made necessary the installation of products and construction systems having acoustic performance namely for medium and treble frequencies, covering a sufficient portion of the partitions which were previously reflecting (for some: partially) the sound and did not absorb it (for some: not enough).
The existence, on the underside of the ceiling, of an insufficiently absorbing lining installed by others earlier (made of basic tiles) has led to envisage additional soundproofing equipment able to be integrated with the existing whereas being perfectly matching, what is rarely the case with other commercial products.
Were therefore considered when sizing soundproofing equipment:
- firstly, a wallcovering made of a high density made of a high density mineral wool and of a suitable surfacing (fabric) allowing acleaning with a wet cloth
- secondly, acoustical screens made of a high density made of a high density mineral wool and of a suitable surfacing (fabric) allowing acleaning with a wet cloth (tailor made, with base)
In addition, an acoustic partition was installed to delineate the area for storing food using noisy equipment for temperature maintenance.
The prediction (computer calculation) of the characteristics of the restaurant after acoustical works founding the commitment to results taken by ITS in-situ (reverberation time guaranteed) on the basis of a quantity of materials to implement (area of surfaces treated obviously impacting the cost of the works) to the liability of ITS was performed by ITS using the simulation software SILDIS (cf. acoustics simulation software).
The measurement of the reverberation time after works (reaching the level "high performance" envisaged by the reference standard) has allowed to check the obtainment of the announced performance in terms of acoustics (the - favorable - discrepancy between prediction and measurement being below 0.09 s at medium and high frequency, what demonstrates an optimized design). A judicious choice of colors for the absorbing panels from a swatch rich of its diversity has helped to obtain a welcoming and very decorative visual atmosphere.
In addition, the course of this project shows - once again - the possibilities for design and optimization of the software SILDIS, whose computing power and reliability, as well as whose versatility made of it a choice tool for the selection of products and construction systems for many projects of sound insulation.