Noise emissions from industrial establishments must be limited to avoid a sanctionable disturbance for the neighborhood: ITS intervenes for the prevention of noise pollution (measurements and solutions) i.e. for noise levels complying with regulations.
Basis of regulations for the prevention of noise annoyance
In terms of prevention of nosie annoyance, the diurnal period (07:00 to 22:00 except Sundays and public holidays) and the night period (22:00 to 07:00 as well as Sundays and public holidays) can often be distinguished.
In some cases, a prefectural decree (when it is not ministerial) sets the noise levels not to exceed in limit of property: this is the case of Classified Facilities for the Protection of the Environment (CFPE). For example, 70 dB (A) in the daytime period and 60 dB (A) during the night period are typical values for these maximum allowable levels.
In any case, the emergence i.e. the difference between the A-weighted equivalent continuous pressure levels of the ambient noise (establishment in operation) and the residual noise (in the absence of the noise generated by the establishment, but measured on the operating period of the establishment) is limited in Regulated Emergence Zones (REZ), which generally include, near the industrial establishment: houses, building zones and areas occupied by third parties e.g. Public Acces Buildings (PAB), other industrial establishments.
If the ambient noise level in the REZs (including the noise of the establishment) is between 35 dB (A) and 45 dB (A) then the permissible emergence is 6 dB (A) in the daytime and 4 dB (A) in the night period.
If the ambient noise level in the REZs (including establishment noise) is greater than 45 dB (A) then the permissible emergence is 5 dB (A) in the daytime period and 3 dB (A) in the night period.
In the case of an CFPE, the marked tone, the presence of which is related to the difference between the sound pressure level in a given 1/3 octave frequency band and the adjacent frequency bands, is considered undesirable if it exceeds 10 dB in the frequency range 50 Hz-315 Hz or 5 dB in the frequency range 400 Hz-8000 Hz.
Measurements and solutions for the prevention of noise annoyance
Noise measurements make it possible to control, and - if - necessary - to highlight noise annoyance in the environment of an industrial site, requiring (what ITS has):
- duly calibrated and verified sound level meters (with appropriate data processing software)
- a human resource qualified and experienced in physical measurements (with a specialty in instrumental techniques)
A study (i.e. an engineering mission) is useful for the research and development of solutions ((e.g. definition and selection of soundproofing materials with quantified and verifiable performance), involving (present at ITS):
- design office staff with expertise (often: in building physics, as far as acousticians are concerned)
In terms of solutions, the limitation of noise emissions from industrial establishments with respect to environment often requires buildings with high acoustic performance to limit the outward transmission of noise from machinery and production equipment, soundproofing devices for equipment installed outdoors (e.g. fans, refrigeration units, dust collection networks) or silencers to limit the noise emitted by orifices at the ends of networks intended for the transport of fluids, under pressure or not.
ITS can assist you for all your projects related to the limitation of noise annoyance from industrial establishments by marketing such solutions, if necessary based on on-site measurements: sizing through studies including simulations in acoustics is included.
ITS' area of expertise for the prevention of noise pollution (measures and solutions) extends to all industrial sectors, this being well in line with the slogan "Choice soundscapes, everywhere."