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Acoustic comfort
WHAT IS NOISE?
Noise in buildings is considered to be detrimental to health and quality of life. Efforts have been made in the last 30 years to attenuate the sounds coming from the street, worsening the perception of sounds emitted within buildings. Heat insulation policies aimed at reducing energy consumption will also heighten these perceptions. Among the priority criteria in the comparative performances of drainage materials, acoustic performance is considered to be second only to fire safety: cast iron pipe systems have intrinsic acoustic properties. Owing to the development of equipment accessories, they offer outstanding performances.
NOISE FROM PIPE SYSTEMS
Noise from waste water pipe systems is classified under the regulation in the “equipment noises”. Noise originating from pipe systems is due to the sound energy produced by water/air turbulence, but mostly by the mechanical effect of the water-flow on the internal pipe walls. In such circumstances a pipe will radiate noise outwards and transfer it to any lightweight ceilings, cupboards and similar areas wherever it makes contact.
Noise is an energy affecting air pressure and is transmitted through vibration.
Sound is measured in decibels (dB) using a nonlinear scale. For noise from equipment apparels, the following categories are identified and measured:
NOISE FROM PIPE SYSTEMS
Noise from waste water pipe systems is classified under the regulation in the “equipment noises”. Noise originating from pipe systems is due to the sound energy produced by water/air turbulence, but mostly by the mechanical effect of the water-flow on the internal pipe walls. In such circumstances a pipe will radiate noise outwards and transfer it to any lightweight ceilings, cupboards and similar areas wherever it makes contact.
Noise is an energy affecting air pressure and is transmitted through vibration.
Sound is measured in decibels (dB) using a nonlinear scale. For noise from equipment apparels, the following categories are identified and measured:
Airborne noise:
Air vibrations that are propagated. In the case of wastewater pipe systems, this noise is mainly heard in the room where the pipe is located. When a material is dense and thick, the pipe walls prevent air transmission, as is the case with cast iron which has intrinsic acoustic properties.
Structure-borne noise:
The vibration of a building’s structure. This noise will be noticed in rooms adjacent to the pipe. When the noise produced in a pipe is not transmitted by the air, the residual noise is transmitted by structural vibrations. Whilst the mass of the cast iron limits the vibratory level, the junctions and fixings to the building will propagate noise. Objective: dampen the vibrations at the connections to the solid structure.
Statutory requirements for “equipment noise” for structure-borne noise differentiate between noisy rooms and quiet rooms with sound attenuation requirements. For noisy rooms, the noise level requirements are generally 35 dB or more. For quiet rooms, which are generally living rooms, resting rooms and work rooms, the noise level requirements are generally around 30 dB, in cases where noise regulations exist.
Airborne noise:
Air vibrations that are propagated. In the case of wastewater pipe systems, this noise is mainly heard in the room where the pipe is located. When a material is dense and thick, the pipe walls prevent air transmission, as is the case with cast iron which has intrinsic acoustic properties.
Structure-borne noise:
The vibration of a building’s structure. This noise will be noticed in rooms adjacent to the pipe. When the noise produced in a pipe is not transmitted by the air, the residual noise is transmitted by structural vibrations. Whilst the mass of the cast iron limits the vibratory level, the junctions and fixings to the building will propagate noise. Objective: dampen the vibrations at the connections to the solid structure.
Statutory requirements for “equipment noise” for structure-borne noise differentiate between noisy rooms and quiet rooms with sound attenuation requirements. For noisy rooms, the noise level requirements are generally 35 dB or more. For quiet rooms, which are generally living rooms, resting rooms and work rooms, the noise level requirements are generally around 30 dB, in cases where noise regulations exist.
COMPARATIVE LABORATORY TESTS
Acoustic comfort is a differentiation criterion that indicates construction quality. The building project manager and specifier may define together specific requirements to improve the final construction.
In 2019, PAM Building commissioned a series of comparative tests on airborne and structure-borne noises in installation conditions described by standard EN 14366*, at the Fraunhofer Institute for Building Physics in Stuttgart.
The measurement results for the PAM Building cast iron pipes listed in the table were determined at the Fraunhofer Institute for Building Physics on an installation wall with a basis weight of 220 kg/m2.
The prerequisite for this was that the building conditions in the real construction situation be comparable to or more favorable than the test bench of the Fraunhofer Institute for Building Physics in terms of sound technology.
When compared with the requirements, pay attention to the simultaneous operation of plumbing installations and possible interactions among the plumbing components which may produce different results. As a comparison value with the requirements, the measured value should be obtained at a flow rate of 2.0 l/s, because this corresponds to approximately one toilet flush. The sound measurements were taken both on the opposite side of the installation (in the picture on the right) and in the mounting room (on the left of the picture).
Details of the tests configuration :
- Standard bracketing: 2 bracket collars per floor. Both mounted with a 1 Nm torque.
- Stack support: Stack supports are fixed to the wall/floor.
- PAM’Acoustic: 2 anti-vibration brackets per floor. Both mounted with a 1 Nm torque.
Details of the tests configuration :
- Standard bracketing: 2 bracket collars per floor. Both mounted with a 1 Nm torque.
- Stack support: Stack supports are fixed to the wall/floor.
- PAM’Acoustic: 2 anti-vibration brackets per floor. Both mounted with a 1 Nm torque.
Tests results for the installations, According to EN 14366
| Pipe system | Test report N° | Installation acc. to EN 14366 | |||
| Airborne noise (La,A) | Structural noise (LSC,A) | ||||
| 2.0 (l/s) | 4.0 (l/s) | 2.0 (l/s) | 4.0 (l/s) | ||
| S range + classical bracketing with rubber and stack support in basement floor | PB-A 223/2019 | 47 db (A) | 50 db (A) | 21 db (A) | 26 db (A) |
| S range + PAM'Acoustic without stack support in cellar | PB-A 226/2019 | 47 db (A) | 50 db (A) | <10 db (A) | <10 db (A) |
Complete reports are available on request. Sound levels below 10 dB(A) are not mentioned in the test report.
Structure borne noise & Pam’Acoustic
For the requirements of extreme acoustic comfort (luxury buildings, auditoriums...), Pam’Acoustic is an acoustic dampener, which, placed between the frame and the support collar of the cast iron pipe, makes it possible to achieve the exceptional structural noise level of 10 dB (A), that is, almost silence.
Tests according to standard NF EN 14366 (IBP laboratory).
For a flow rate of 2 liters/second, wall: 220 kg/m².
NOISE IN REAL CONDITION OF USE
Usually pipe systems are installed in a technical shaft that contributes to reducing the noise emitted by the effluent flowing in a pipe. Nevertheless, the noise level of pipes installed behind a shaft may not be sufficient to comply with the specifications of the owner or set by the national regulation.
In 2018, PAM Building initiated several noise measurement tests with an independent laboratory in real conditions, inspired by standard EN 14366, but using a real WC flush to assess the noise level of the combination of pipe material and shaft acoustic performance (ΔLan).
Below are some examples of measurements at a flow rate of 2 l/s with the S range fixed on a 15 cm thick supporting concrete wall:
| Technical Shaft | S range with rubber lined steel brackets |
S range with steel brackets and acoustic dampener |
| ΔLan Performance | LA,S,max [50-5000 Hz] (dB) | LA,S,max [50-5000 Hz] (dB) |
| 19 ≤ ΔLan < 24 | 33 | 32 |
| 24 ≤ΔLan < 29 | 30 | 25 |
| 29 ≤ΔLan < 34 | 29 | 19 |
Choosing our systems guarantees the best acoustic solution on the market.
Depending on your project specification or national regulation, PAM Building can help you validate your pipework’s compliance. Please contact our technical support team on our website: Please contact our technical assistance.
Summary of our solutions :
- High basis weight
- Low tendency to vibrate
- Effective sound decoupling
- High insulation value
- Suitable for all pressures
- Sewage installations
- Precise installation instructions
- Compliance with project specification or regulation
Summary of our solutions :
- High basis weight
- Low tendency to vibrate
- Effective sound decoupling
- High insulation value
- Suitable for all pressures
- Sewage installations
- Precise installation instructions
- Compliance with project specification or regulation