Reducing the noise of fans and other extractors is a necessity induced by the presence of such equipment, the sound emissions of which are by nature significant, in many situations where they are likely to cause noise nuisance (annoyance).

In buildings, when it comes to Controlled Mechanical Ventilation (CMV) or for any other Heating Ventilation Air Conditioning (HVAC) installation: air conditioners, heat pumps and air coolers, e.g. associated with refrigeration, therefore occupy, as soon as they include at least one fan, a place of choice among the equipment frequently incriminated for the noise nuisance (annoyance) caused; extractors in professional kitchens can also be a problem, as can ventilation systems in technical rooms.

Within industrial sites, ventilation systems are frequently required:

  • for many installations for which air renewal (i.e. fresh air supply and foul air exhaust) must be provided periodically
  • for the evacuation of effluents: for painting booths, for combustion processes (e.g. for industrial chimney draft fans)
  • for the evacuation of the heat energy dissipated by equipment which must be cooled: for heat engines (for some: generator sets, with or without coupled fan), but also: for pumps, compressors and other equipment in technical rooms, machine rooms, enclosures hosting various hardware, whether they are underpressurized or overpressurized
  • for many processes involving heat exchange by forced convection (e.g. with air condensers, cooling towers)
  • for many material suction and transport systems (parings, shavings, sawdust)

Depending on its power, the noise from fans and other extractors can have a more or less negative impact on the space in which they are installed and/or on adjoining or more distant spaces.

Depending on the context, inhabitants or users of a construction (house, hotel, educational or health establishment, sports halls), employees (including sometimes: in an office) or neighbors of an industrial site must be protected against noise from fans and other extractors: excessive noise emissions can cause noise nuisance (annoyance), which places those responsible for it in a violation situation.

Noise from fans and other extractors is an important area of activity for ITS, whose contributions to a project to limit noise nuisance (annoyance) can be multiple (if necessary: all at the same time), also in the context of complex aeraulic networks:

  • measurement of noise levels emitted at specified locations
  • simulation of the sound impact
  • analysis and characterization of noise nuisance (annoyance) e.g. exceeding limits of sound pressure level, non-compliance with emergence criteria, with or without marked tone
  • study, definition, and prediction of the effectiveness of actions and noise reduction devices (silencers for fans and other extractors can be dimensioned by ITS as for their acoustic and aerodynamic performance with in-house software or with tools trade: CFD, FEM, BEM)
  • marketing of soundproofing equipment, with or without installation