Noise pollution: a major challenge for quality of life
Noise is an integral part of our daily environment. However, when it becomes excessive, repetitive, or poorly controlled, it turns into noise pollution that can negatively impact comfort, health, and overall quality of life.
Prolonged exposure to noise goes beyond simple annoyance. Studies in environmental health show that noise can have multiple effects on the human body. The most common impacts affect hearing: auditory fatigue, tinnitus, or even hearing loss in cases of prolonged exposure to high sound levels.
(source: ADEME, CNB 2021)
(source: WHO, 2022)
With increasing urban density and the growing number of technical systems in buildings, noise sources have diversified. Beyond external noise, many disturbances now originate from building services: ventilation systems, air conditioning units, pumps, chillers, and ductwork.
While essential for thermal comfort and indoor air quality, these systems can generate significant noise levels and propagate sound throughout the building if not properly treated.
This is why noise control has become a key factor in building design and operation. It relies on a comprehensive approach combining acoustics, aeraulics, and regulatory compliance to ensure a comfortable and compliant sound environment.
HVAC acoustic treatment: reducing noise from ventilation systems
In modern buildings, ventilation and air conditioning systems are now one of the primary sources of technical noise.
In HVAC engineering, systems used for air treatment and distribution inevitably generate noise. This noise propagates through:
- Airborne transmission along ventilation ductwork
- Radiated noise from equipment and duct surfaces
- Structure-borne transmission via vibrations from fans and building structures
Just like thermal comfort, acoustic comfort has become a key requirement for building users.
A perfectly air-conditioned office can quickly become uncomfortable if it is too noisy. A healthcare facility must meet strict sanitary requirements without generating constant acoustic stress. A hotel may provide ideal temperature conditions but compromise sleep quality due to poorly controlled ventilation noise.
HVAC systems are therefore among the main sources of technical noise in commercial, healthcare, industrial, and residential buildings.
Each component has its own acoustic signature, which must be taken into account in the overall system design.
Noise never remains confined to its source. It propagates throughout the entire ductwork system and interacts with the building environment: room volumes, construction materials, reverberation time, equipment layout, and duct network configuration.
Controlling HVAC noise therefore requires a comprehensive approach combining acoustic analysis, aeraulic design, and appropriate treatment solutions—such as acoustic silencers—to ensure optimal acoustic comfort for occupants.
Beyond user comfort, managing noise from HVAC systems must also meet strict regulatory requirements aimed at limiting noise pollution within buildings and their surrounding environment.
Acoustic regulations for HVAC systems
Noise control in heating, ventilation, and air conditioning systems is not limited to a comfort objective. It is also governed by regulatory texts aimed at limiting noise disturbance within buildings and in their surrounding environment.
In the field of HVAC engineering, systems (air handling units, fans, chillers, or ventilation ductwork) must comply with acceptable noise levels in occupied spaces, as well as with noise limits with respect to neighboring environments.
These regulatory requirements must be taken into account from the design stage of installations in order to ensure acoustic comfort for occupants and compliance of the building
The concept of noise emergence
French regulations on neighborhood noise are based in particular on the concept of noise emergence, defined as the difference between:
- Ambient noise, including the operation of the installation
- Residual noise, corresponding to the usual background noise of the environment in the absence of the equipment
Decree No. 2006-1099 of 31 August 2006 relating to the control of neighborhood noise sets the following limits (for noise with a cumulative duration of occurrence of 8 hours):
5 dB(A) maximum
during daytime (7 a.m. – 10 p.m.)
3 dB(A) maximum
during nighttime (10 p.m. – 7 a.m.)
Regulations also impose specific emergence limits:
7 dB
in normalized octave bands centered at 125 Hz and 250 Hz
5 dB
in normalized octave bands centered at 500, 1000, 2000, and 4000 Hz
These values require rigorous design of technical installations, particularly for equipment located near residential buildings or sensitive areas.
Permissible noise levels in buildings
The decree of April 25, 2003, establishes permissible noise levels in buildings open to the public, particularly in the hospitality, healthcare, and education sectors. These requirements aim to ensure optimal acoustic comfort in sensitive areas while limiting noise generated by building services such as ventilation, heating, or air conditioning systems (HVAC).
As a guide:
Hotels: The noise level in guest rooms must not exceed 30 dB(A) when the noise originates from building equipment. This limit may reach 35 dB(A) when the equipment (heating or air conditioning) is installed directly in the guest room.
Healthcare facilities: Acoustic requirements are particularly strict, with levels of approximately 30 dB(A) in patient rooms, 35 dB(A) in examination or waiting rooms, and up to 40 dB(A) in certain treatment rooms.
Educational institutions: permissible noise levels are approximately 33 dB(A) in areas requiring a quiet environment (libraries, infirmaries, rest rooms) and may reach 38 dB(A) in classrooms or activity areas.
Standard NF S 31-080 (January 2006) defines the following acoustic objectives for offices and associated spaces
| Spaces | Levels | ||
|---|---|---|---|
| STANDARD | HIGH PERFORMANCE | VERY HIGH PERFORMANCE | |
| Individual offices | LAeq ≤ 45 dB(A) | Lp ≤ NR 33 | Lp ≤ NR 30 (continuous) and Lmax ≤ 35 dB(A) (intermittent) |
| Shared offices | LAeq ≤ 45 dB(A) | Lp ≤ NR 33 | Lp ≤ NR 30 (continuous) and Lmax ≤ 35 dB(A) (intermittent) |
| Open-plan offices | LAeq ≤ 45 dB(A) | NR 35 ≤ Lp ≤ NR 40 | Lp ≤ NR 33 (continuous) and Lmax ≤ 35 dB(A) (intermittent) |
| Open spaces (shell & core) | LAeq ≤ 45 dB(A) | Lp ≤ NR 33 | Lp ≤ NR 30 (continuous) and Lmax ≤ 35 dB(A) (intermittent) |
| Meeting / information rooms | LAeq ≤ 40 dB(A) | Lp ≤ NR 33 | Lp ≤ NR 30 (continuous) and Lmax ≤ 35 dB(A) (intermittent) |
| Break areas | LAeq ≤ 40 dB(A) | Lp ≤ NR 33 | Lp ≤ NR 30 (continuous) and Lmax ≤ 35 dB(A) (intermittent) |
| Restaurant | LAeq ≤ 50 dB(A) | Lp ≤ NR 35 | Lp ≤ NR 30 (continuous) and Lmax ≤ 35 dB(A) (intermittent) |
| Circulation areas | LAeq ≤ 45 dB(A) | Lp ≤ NR 33 | Lp ≤ NR 30 (continuous) and Lmax ≤ 35 dB(A) |
Our expertise: integrating acoustics from the design stage of HVAC systems
Compliance with acoustic regulations requires integrating acoustics from the early design phase of technical installations.
An acoustic study of HVAC ductwork systems makes it possible to:
- Identify the main noise sources
- Analyze sound propagation within ventilation ductwork
- Ensure compliance with regulatory acoustic targets
- Size appropriate acoustic treatment solutions (silencers, anti-vibration devices, or enclosures)
This approach ensures regulatory compliance while delivering long-term acoustic comfort for occupants.
Our acoustic expertise in aeraulics: a comprehensive approach to HVAC acoustic design
Our acoustic expertise in aeraulics positions us as a trusted advisor to HVAC contractors, enabling us to meet client expectations as well as the acoustic specifications defined by specialized consulting engineers.
Noise control in ventilation and air conditioning systems relies on a comprehensive approach combining acoustics and aeraulics—two inseparable disciplines in HVAC ductwork design. At F2A, we combine these areas of expertise to ensure optimal integration of acoustic equipment within ventilation systems, while maintaining the aeraulic performance of the installation.
For each HVAC acoustic study, our team relies on Aircoustic, a software tool developed by our acousticians and enhanced by over 25 years of experience in aeraulic acoustics. This calculation tool is based on recognized references in HVAC engineering and building acoustics, including ASHRAE guidelines, VDI 2081, and NF EN 12354-5, enabling precise modeling of noise propagation within ventilation systems.
Our expertise is based on a comprehensive analysis of the acoustic behavior of HVAC installations. We specifically study the sound power of equipment, the sound pressure levels actually perceived in occupied spaces, and the octave band spectrum distribution in order to identify critical frequencies. Noise propagation is modeled globally, taking into account the direct field, the reverberant field related to room reverberation time, the directivity factor of sources, as well as airborne and structure-borne transmission within ventilation systems.
Each project begins with a rigorous collection of technical data related to equipment and building architecture. We then carry out a complete modeling of the aeraulic network, including self-generated noise phenomena caused by bends, dampers, control devices, or diffusers, as well as the insertion loss of HVAC silencers.
The analysis of the most critical room finally allows us to accurately size acoustic treatment solutions by identifying the best compromise between acoustic attenuation, pressure losses, and aeraulic performance. This structured and comprehensive approach ensures measurable results, compliant with regulatory requirements and perfectly adapted to the real constraints of the installation.
The information you need to provide us for conducting an acoustic study:
| DATA TO BE PROVIDED | ELEMENTS CONCERNED | FORMATS |
|---|---|---|
| Sound power spectra | Air handling equipment:
| Octave band format |
| Acoustic characteristics | Ductwork components:
| Octave band format |
| Airflow rates | Air handling units Served areas Diffusers | Octave band format |
| Drawings and sections | Floor plans Ductwork networks | DWG files |
| Acoustic targets | Acoustic specifications or technical requirements (CCTP) |
Our industrial acoustic expertise: controlling equipment noise radiation
In addition to its expertise in aeraulic acoustics, F2A designs and develops custom acoustic enclosures aimed at effectively reducing noise emissions generated by technical and industrial equipment.
This acoustic enclosure solution makes it possible to contain noise sources while maintaining the operational performance of installations such as air handling units, fans, compressors, pumps, or industrial machinery.
F2A acoustic enclosures are based on a modular and scalable design, allowing the solution to be adapted to the installation configuration and operational constraints. The enclosures can integrate various acoustic treatment elements such as silencers or acoustic grilles, in order to optimize noise attenuation while ensuring proper equipment ventilation.
The panels are made of galvanized steel sandwich panels incorporating sound-absorbing materials such as mineral wool or glass wool, combined with a perforated inner facing to enhance acoustic absorption. This design enables overall noise reductions ranging from 10 up to 50 dB(A) depending on project configuration and requirements.
Designed for industrial operation, F2A acoustic enclosures also ensure easy maintenance access through doors, hatches, and removable panels, while offering excellent resistance to harsh outdoor conditions. Solutions can be delivered as standard modules or fully custom-built systems, adapting to any type of equipment and technical environment.
Thanks to this approach combining acoustic analysis, mechanical design, and aeraulic integration, F2A provides complete, turnkey acoustic solutions capable of significantly reducing noise emissions while meeting regulatory requirements and maintaining equipment performance.
Acoustic treatment solutions: silencers, splitters, enclosures, screens, grilles…
To effectively address noise issues generated by HVAC systems and industrial equipment, F2A develops and integrates various acoustic treatment solutions tailored to the technical constraints of each project. These solutions reduce noise propagation while maintaining aeraulic performance and proper equipment operation.
Thanks to its expertise in acoustics and aeraulics, F2A offers a comprehensive approach combining acoustic analysis, equipment design, and integration into the technical environment. Depending on the nature of noise sources and system configuration, several solutions can be implemented: silencers, acoustic enclosures, acoustic screens, acoustic grilles, or anti-vibration devices.
Silencers are designed to reduce the propagation of sound waves within ventilation and air conditioning ductwork. Installed in supply or return ducts, they effectively attenuate noise generated by air handling units, fans, or control devices.
Thanks to specially sized sound-absorbing splitters, HVAC silencers can treat different frequency bands while limiting pressure losses in the ductwork. Their design is optimized to ensure the best compromise between acoustic performance and aeraulic efficiency, in compliance with consulting engineers’ requirements and installation constraints.
When noise originates directly from technical or industrial equipment, the most effective solution is often to treat it as close as possible to the source using an acoustic enclosure.
F2A acoustic enclosures are modular solutions designed to significantly reduce noise emissions generated by equipment such as compressors, pumps, fans, production machinery, or air handling units.
Designed using galvanized steel sandwich panels incorporating sound-absorbing materials such as mineral wool or glass wool, these enclosures provide both acoustic insulation and absorption. Their design enables noise reductions of up to 50 dB(A) depending on project configuration.
F2A acoustic enclosures are engineered to meet operational constraints: easy maintenance access through doors and removable panels, integrated ventilation via acoustic grilles or air silencers, and a modular structure allowing fully customized installation to suit the equipment configuration.
In certain configurations—particularly for outdoor or rooftop installations—it is often preferable to limit noise propagation to the surrounding environment rather than fully enclosing the source. In such cases, acoustic screens provide an effective solution.
F2A acoustic screens are made of modular panels combining sound absorption and insulation, creating an acoustic barrier around noisy equipment such as chillers, industrial fans, air handling units, or exhaust systems, which are often significant noise sources in residential environments.
These solutions can be configured as single-sided or multi-sided screens, or even as a complete technical enclosure surrounding the equipment. Their design allows for significant noise reduction while maintaining natural ventilation, making them particularly suitable for outdoor and rooftop installations, as well as for equipment requiring very low pressure drop.
In installations requiring air renewal, acoustic louvres make it possible to combine ventilation with noise reduction. They are designed to limit the propagation of sound waves while ensuring proper airflow through technical rooms, acoustic enclosures, or equipment housings.
Integrated into enclosure facades, technical rooms, or air intakes, acoustic louvres effectively reduce noise generated by air handling units, chillers, or fans. They therefore provide a complementary solution to HVAC silencers for the acoustic treatment of ventilation openings.
Beyond their acoustic performance, F2A acoustic louvres also stand out for their refined design (rounded blades) and compact footprint, allowing seamless architectural integration into building façades. This attention to aesthetics makes them particularly well suited for commercial buildings, hotels, healthcare facilities, and high-end architectural projects, where technical equipment must remain discreet while ensuring a high level of acoustic performance.
Noise from HVAC systems can also be transmitted through mechanical vibrations via building structures. To limit these structure-borne transmission phenomena, F2A offers antivibration systems designed to isolate equipment from their supports.
These solutions effectively reduce the propagation of vibrations generated by fans, chillers, pumps, or air handling units, preventing their transmission to the building structure. Antivibration systems therefore contribute significantly to improving the overall acoustic comfort of technical installations.
Partnerships and acoustic sizing tools
To support consulting engineers, contractors, and operators in selecting acoustic treatment solutions, F2A provides dedicated tools designed to facilitate system sizing and equipment selection.
As part of this approach, F2A notably relies on Esonie, a free acoustic sizing software developed for HVAC and building professionals. This tool helps optimize the selection of HVAC silencers based on the required attenuation levels and enables analysis of noise sources using octave band sound spectra.
Designed for ease of use, e·sonie features an intuitive interface, clear project management, and the ability to save and share calculations. Users can determine the sound power level after silencers, estimate the sound pressure level at a given distance, and directly access the full F2A acoustic product range, including data for rectangular and circular VAV units.
Results can be exported in various formats, facilitating their integration into technical studies and design documentation. As part of the acoustic treatment process using silencers, the tool also enables the sizing of antivibration systems, helping to effectively limit the transmission of vibrations within building structures.
Thanks to these tools and the support of our teams, F2A enables HVAC professionals to quickly identify the most suitable acoustic solution, while ensuring optimal integration of equipment within a comprehensive approach to noise and vibration control.
Our teams are available Monday to Thursday from 8 a.m. to 5:30 p.m. and Friday from 8 a.m. to 4:30 p.m.