The consideration of acoustics and aeraulics in a construction project is necessary in relation to different works trades: architectural, technical, not to mention the envelope.

SILDIS software makes it possible to easily, quickly, and reliably perform Computer Aided Design tasks with regard to related issues.

All calculations are possible taking into account contextualized thermodynamic conditions:

  • for ambient air (e.g. for ordinary applications in the building sector with the exception of those related to exhaust gases, involving high temperatures, for which calculations are also possible)
  • as required for simulations in the context of industrial construction projects (possibly with fluids other than air and extreme conditions)

The fact that the software is in Excel format, with drop-down menus and with the possibility of selecting materials from libraries [1] makes it a practical tool for various participants in the construction process: project managers, architects, consultants, technicians and engineers from design offices (acousticians, specialists in aeraulics and fluids) and manufacturers Research and Development (R&D) centers.

Sound transmission through partitions

The software allows the prediction of the sound reduction index of walls, possibly multilayer, for sound insulation:

    • constituting the envelope of buildings: walls, slabs, roofs or subject to interior carpentry work (e.g. metal or wood joinery) and plastering: partitions, ceilings, linings, not to mention industrial acoustic insulation panels, screens (noise barriers) and also components of glass doors and frames
    • constituting the envelope of silencers inserted in ventilation and air conditioning networks or in chimneys

Calculations are possible by combining plates (e.g. concrete, plaster, wood, steel, aluminum, glass) [2], possibly joined together, and fibrous materials (glass wool, rock wool, basalt wool polyester or ceramic fiber based wool, foams) [3].

The plates can be plane, orthotropic (i.e. with corrugations), perforated, with or without a bonded viscoelastic damping layer (e.g. septum, PVB): extensional or constrained (between 2 plates: sandwich panels).

The results of the calculations are comparable to the standard measurement: cf. NF EN ISO 140-3 Acoustics - Measurement of sound insulation in buildings and of building elements - Part 3: laboratory measurement of airborne sound insulation of building elements.

Sound absorption

The software allows the prediction of the sound absorption coefficient of linings, possibly multilayered, for the limitation of the reverberation of premises:

    • constituting ceiling tiles and suspended baffles, wall panels, laggings, not to mention industrial sound insulation panels, screens (noise barriers) and dividers

Calculations are possible by combining plates (e.g. plaster, wood, steel, aluminum) [4] possibly perforated, fibrous (glass wool, rock wool, basalt wool, polyester ceramic fibers based wool, foams) [3] and surfacing (sails, fabrics) [5]

The results of the calculations are comparable to the standard measurement: cf. NF EN ISO 354 Acoustics - Measurement of sound absorption in a reverberation room and also standard ISO 10534-1 Acoustics - Determination of the sound absorption coefficient and impedance in impedance tubes - Part 1: Method using standing wave ratio.

Limitation of noise transmission in ducts

The software allows the prediction of the insertion loss, of the self noise and of the total pressure loss of elements of aeraulic networks, whose impact, in the event of accumulation, is calculated:

    • silencers [4], either resonant or dissipative (i.e. with absorbent lining, possibly multilayered). The calculations are possible by combining plates (e.g. steel, aluminum) [4] possibly perforated, fibrous (glass wool, rock wool, basalt wool, polyester or based on ceramic fibers wools, foams) [3] and surfacing (cloths, fabrics) [5]
    • straight lengths, elbows, nozzles

The components of the air network can be of rectangular or circular cross section.

For a rectangular silencer, the results of the calculations are comparable with the standardized measurement: see NF EN ISO 7235 Acoustics - Laboratory measurement procedures for silencers in ducts and terminal units - Insertion loss, flow noise and total pressure loss.

In the matter of Computer Aided Design (CAD): SILDIS calculation software for acoustics and aeraulics in the construction sector (in Excel format) is a versatile tool, marketed (with associated training) by Isolation Technologie Services (ITS) in the form of modules, some of which are grouped in packs, according to the needs of users (interface available in French or in English)

The software output data, in terms of simulation of the sound transmission through walls, of sound absorption, of the limitation of noise transmission in ducts, are useful for many projects, allowing sizing and technical optimization of various construction products and systems, in relation to issues being acoustic comfort and / or soundproofing.


[1] the specific characteristics of the materials to be taken into account for the calculations - in addition to the thickness and number of layers, as well as their stacking - are tabulated

[2] the specific characteristics taken into account are the Young's Modulus, the density, the Poisson factor, the loss coefficient

[3] the specific characteristics taken into account are the resistivity, the porosity, the tortuosity, the thermal characteristic length, the viscous characteristic length, the density

[4] the specific characteristics taken into account are the Young's Modulus, the density, the Poisson factor, the loss coefficient, the installation conditions (free or embedded), and, in the case of perforated plates: the porosity, the geometry of the perforations

[5] the specific characteristics taken into account are the resistance to air passage, the surface mass

[6] the specific characteristics taken into account are the flow rate, the dimensional parameters (e.g. geometry of the internal parts, length)