Acoustics and antivibration address nuisances that can look identical — “noise” — but stem from very different physical sources. Understanding that distinction avoids costly and often ineffective interventions. Below we clearly separate the two, present the families of associated products and explain in which contexts to use them.
What is acoustics?
Acoustics deals with sound energy that propagates through the air. Concretely, it is the sound as we perceive it: tonal components, the hiss of an airflow, the whine of a fan, the radiation from a generator, noise on construction sites, etc. Acoustic solutions aim either to reduce the sound emitted at the source or to interrupt or absorb its path toward the receiver (a person, an adjacent room, a façade). Acoustics is evaluated using sound pressure measurements (dBA), commonly called decibels, and frequency analysis is used to determine the most effective solutions.
Noise regulation
Acoustics is heavily regulated by laws and standards intended to protect citizens’ health and quality of life against noise nuisances. These standards vary by jurisdiction (federal, provincial, municipal) but generally establish:
- Maximum permitted sound levels (dBA) for different environments (residential, industrial, commercial, neighborhood).
- Sound transmission requirements for building structures (for example, ITR — Sound Transmission Index — or NIC — Noise Isolation Class) to ensure adequate isolation between units or rooms.
Compliance with these rules often requires applying basic acoustic principles during construction or when adding equipment (on roofs, in enclosures, on construction sites, etc.). Several solutions are available depending on the source, the noise type and the sound level.
Companies commonly call on acoustic engineers to perform noise studies and issue a report that will either confirm compliance with required sound levels or propose mitigation measures to reduce noise pollution.
Acoustic products and when to use them
Once the noise source has been properly identified and depending on the location and sound level, several solutions can be offered. The main ones are:
- Duct silencers (acoustic silencers): installed at the air inlets and outlets of ventilation systems and in mechanical rooms. They reduce noise related to airflow and ventilation tonalities. Silencers are often sized and tested according to standards (e.g., ASTM E-477) to guarantee performance.
- Acoustic panels and screens: used indoors and outdoors to create a visual and acoustic barrier around a source (generator, fan, cooling tower, construction site). They block the direct acoustic line-of-sight and absorb energy, which is useful near occupied spaces or sensitive façades.
- Enclosures / caissons: “turnkey” solutions for compressors, generators and other highly radiating machines. An enclosure greatly limits sound radiation and helps meet dB targets.
An acoustic solution is chosen when the nuisance is primarily air-borne — that is, when the sound is transmitted directly through the air rather than via the building structure.
What is antivibration?
Antivibration deals with mechanical movements: displacements, oscillations, accelerations of a machine or a component. These vibrations propagate through the structure (floor, mezzanine, piping) and can result in secondary noise, mechanical fatigue, loosening of assemblies, or discomfort for occupants. The goal of antivibration is to prevent mechanical energy from leaving the source or to reduce its amplitude before it reaches the structure.
Antivibration products and when to use them
- Damping pads (damping pads — series DP, blues foam, RCR, RP, RSR): placed under ventilation units, pumps (horizontal and vertical) or plumbing equipment. They absorb energy at the support point and are convenient for retrofits. Choice depends on rubber hardness, thickness and resistance to oil or liquids.
- Elastomeric mounts (rubber mounts / floor mounts — VIB, VIBS, etc.): designed for equipment that must be bolted to the floor (condensers, transformers, chillers). They combine mechanical restraint with isolation. There are seismic and non-seismic models depending on site requirements.
- Floor isolators (SM1, SM2, VSR1, VSR2): used under heavy machines on mezzanines or sensitive floors. These isolators provide deflection (e.g. 1″ or 2″) that is effective for low frequencies where simple foam is insufficient. They are preferred when the vibratory tonal content is critical.
- Hanger isolators (series EHD, SHE, SHM, SHL, etc.): intended for suspended equipment (fans, fan-coils, piping). They protect the slab and structure by absorbing transmitted vibrations. By default these isolators are not seismic — seismic cables must be added when building codes require them.
- Pump support (VPS model, seismic-approved): for vertical pumps; it secures the pump to the floor while attenuating vibration. It is recommended to install grommets and complementary pads (RSR) to absorb high frequencies.
- Seismic antivibration rail (aluminum extrusion): designed for rooftop units and heavy fans on roofs; it offers a recommended deflection (e.g. 1″) and adapts to various unit sizes and brands.
- Inertia base (custom): a solution for very powerful machines (boosters, large pumps, high-power fans). By increasing the support mass, the system dynamics change and transmitted vibration amplitude is reduced. These bases are sized according to machine horsepower and vibratory characteristics.
How to choose between acoustics and antivibration (or when to combine them)
The process always begins with measurement and analysis: determine whether the nuisance is air-borne (measured in dB, direct sound) or structure-borne (vibrations measurable in mm/s or m/s², tactile sensation, resonances). If the source vibrates strongly and transmissions are observed in the structure (floor shaking, piping “singing”), antivibration is the priority. If the problem is an airflow whistle or a sound radiating toward a façade or neighbor, acoustic treatments are the right approach.
In many cases — a pump that vibrates and “makes noise” — an effective solution combines both: mechanical isolation (pads, mounts, inertia base) to interrupt structure-borne transmission, followed by silencers, panels or enclosures to reduce the residual acoustic radiation.
Practical rules for implementation
- Measure before acting: set a quantified objective (dB reduction, vibration value not to exceed).
- Consider the environment: presence of oil, humidity, outdoor exposure — these factors guide material selection.
- Respect seismic requirements: some isolators are non-seismic and require cables or certified models depending on the building.
- Test after installation: measure again and adjust (change pad hardness, add mass, modify the enclosure).
Conclusion
Acoustics and antivibration address distinct but complementary needs. A successful intervention starts with a rigorous diagnosis: identify the source, measure the levels and choose the appropriate technology. In training, the goal is to give teams the tools to make the right diagnosis, select the right product (pads, mounts, hanger isolators, rails, silencers, panels, enclosures, inertia bases) and verify effectiveness after the work. Solutions exist — their performance depends on analysis and correct technical choices.