The reduction of noise pollution due to Air Handling Units (AHU), is at the heart of the activity of ITS, which offers a diversified range of products and services.

When is the reduction of noise annoyance due to Air Handling Units (AHU) necessary ?

Reducing noise annoyance due to Air Handling Units (AHU) is a necessity in many contexts (in France) :

  • with regard to the regulations relating to the impact of noisy equipment inside buildings :
    • in residential buildings: for noise generated by an individual heater or individual air-conditioning unit in a dwelling, this level shall not exceed 35 dB (A) in the main rooms and 50 dB (A) in the kitchen of this accommodation; however, when the kitchen is open on a main room, this level, for an individual heater of the dwelling operating at minimum power shall not exceed, in the main room on which gives the kitchen of this dwelling: 45 dB(A), for dwellings that have been the subject of an application for a building permit or a declaration of works relating to the elevations of old residential buildings and the additions to such buildings, submitted between 1 January 2000 and 31 December 2000 and 40 dB (A) as from 1 January 2001
    • equipment noise for constructions covered by the decrees of 25 April 2003 relating to the limitation of noise, in the case of an Air Handling Unit (AHU) as building equipment :
      • in educational institutions :
        • for noise generated in libraries, documentation and information centers, medical premises, infirmaries and rest rooms, music rooms by an equipment related to the building, this level shall not exceed 33 dB (A) if the equipment operates continuously and 38 dB (A) if it operates intermittently; these levels are increased to 38 and 43 dB (A) respectively for all other reception areas
      • in hotels :
        • for noise generated in the rooms by an equipment, whether collective or individual, related to the building, this level must not exceed 30 dB (A); this value is raised to 35 dB (A) when the equipment is installed in the room (heating, air conditioning)
        • for noise generated in an accommodation premise by an equipment related to be building and located outside this room, this level must not exceed 30 dB (A) in general and 35 dB (A) for hydraulic and sanitary equipment in neighboring accommodation premises
      • in health facilities (regarding equipment noise) :
        • for noise transmitted by the operation of a collective equipment related to the building this level must not exceed the following values: in examination and consultation rooms, medical and nursing offices, waiting rooms: 35 dB(A) ; in treatment rooms: 40 dB(A); in operating theaters, obstetrics and workrooms: 40 dB(A)
  • with respect to the regulations relating to noise impact for neighborhood
    • emergence is regulated; this is the difference between the A-weighted equivalent continuous pressure levels of ambient noise (site considered in operation) and residual noise (in the absence of noise generated by the considered site, but measured over its period of operation) - in regulated emergence zones (REZ), and depending on the context - :
      • 5 or 6 dB(A) during the day
      • 3 or 4 dB(A) at night
    • the absence of a marked tone is the ruke (it comes to the difference between the sound pressure level in a frequency band of 1/3 octave 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 )
    • in case of an establishment classified for environmental protection (ECEP), an overall A-weighted noise level not to be exceeded at the property boundaries is imposed by a prefectural authorization decree, e.g. 70 dB(A) during the day, 60 dB(A) during the night

What does ITS offer for the reduction of noise annoyance due to Air Handling Units (AHU) ?

For the reduction of noise annoyance due to Air Handling Units (AHU), ITS offers, depending on the context :

  • on-site acoustic measurements, carried out by a workforce qualified in physical measurements (specialized in instrumental techniques) with sonometry hardware duly calibrated and verified
  • a diagnosis, with comparison of the results of metrological campaigns with the regulatory limits in force, identification and prioritization of the sources of noise at the origin of non-conformities
  • a study for the search for solutions, carried out by an acoustician with a degree in building physics, with sizing of soundproofing equipment [1] [2] whose acoustic and aeraulic performance is calculated: the total pressure loss induced by the implementation of noise attenuators must not degrade the proper functioning of the Air Handling Unit (AHU), which often complicates the development of appropriate construction systems
  • the marketing of soundproofing equipment [1] [2] with or without installation

Spread the word !

[1] depending on the case, the noisiest components of an Air Handling Unit (AHU) can be :

  • compressors
  • axial fans

[2] depending on the context, the equipment to be considered for the reduction of noise pollution due to Air Handling Units (AHU) can be (sometimes: combined) :

  • anti-noise screens and barrier walls with a sound-absorbing side - on the side of the Air Handling Unit (CTA) - (when it comes to reducing the propagation of noise outside)
  • silencers, for suction and/or discharge, as applicable :
    • installed on the Air Handling Unit (AHU), then with soundproofing cover elements to ensure continuity of acoustic insulation and separate air flows to avoid recycling
    • inserted into the aeraulic network, inside a building