Analysis of fitting noise propagation in lightweight steel constructions and design solutions for their prevention (AFINOPRO).
Date: 2013-08-30
Institutions: Directorate-General for Research and Innovation
Subjects: building industry, building materials, noise, noise level, piping, research report, steel, technical standard

European Commission

Research Fund for Coal and Steel

Analysis of fitting noise propagation  
in lightweight steel constructions  
and design solutions for their prevention

(AFINOPRO)

A. Casajus
Forschungs- und Qualitätszentrum Oderbrücke
Werkstraße 20, 15890 Eisenhüttenstadt, GERMANY

J. Ordieres
Universidad Polytécnica de Madrid
José Gutiérrez Abascal, 2, 28006 Madrid, SPAIN

J.L. Abego
ArcelorMittalConstruccion España SL
Carretera de Guipuzkoa 3, 31195 Berrioplano, SPAIN

S. C.Lopez
Instituto de Soldadura e Qualidade
Av. Prof. Cavaco Silva N° 33, 2740 120 Porto Salvo-Oeiras, PORTUGAL

Grant Agreement RFSR-CT-2008-00034 
1 July 2008 – 30 June 2011

Final report

Directorate-General for Research and Innovation

2013 

EUR 26011 EN

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Luxembourg: Publications Office of the European Union, 2013 

ISBN 978-92-79-30790-4 
doi:10.2777/17298 

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Table of Contents 

Final Summary 

Introduction 

Objectives 

1. 

2. 

3. 

          5 

        13

         13

Comparison of initially planned activities and work accomplished 

                                  14 

Planking Material 
Filling Materials 

Description of activities and discussion 

4. 
4.1        Getting started   
4.2  Members 
4.3 
4.4 
4.5  Modules, completed 
Fitting noise 
4.6  
Sound and noise level, quantities 
4.7  
Basic experimental arrangement 
4.8 
4.9 
External conditions FQZO and ISQ 
4.10  What is different from standard EN ISO 3822-1? 

                                                                        15 
        15 
        16 
        16 
        16 
        17 
        17 
        18 
        19 
        21 
        22 

4.11      Measurement field 
4.11.1  Vibrational insulation of the test wall 
4.11.2  Microphone positions 
4.11.3  External noise   

4.12  Measurements with the basic wall, placement 1  
4.12.1  Basic wall 
4.12.2  Suitable fastening for light gauge walls (EN ISO 3822-1 or not)  
4.12.3  The cross-reference measurements gypsum board versus gypsum fibreboard  

Comparison FQZO/ISQ  

4.12.4  The effect of fastening the clamp on a C-profile or aside  
4.12.5  The sound level measurements with the placement 1 
4.12.6  First conclusions 

4.13  The physics of light gauge vibrations by point sources,  

FEM simulation of the wall vibration  

4.13.1  The formulation of the problem  
4.13.2  Boundary conditions 
4.13.3  FEM-Calculation of the single module   
4.13.4  FEM-Calculation of the total wall 
4.13.5  Measurement of wall vibrations, clarification of the art of light gauge vibration   
4.13.6  Vibration measurement of profiles.  

        22 
        22 
        22 
        23 

        23 
        23 
        24 

                     25 
        26 
        26 
        27 

        28 
                     29 
        30 
        33 
        33 
        34 

Clarification how the fitting vibration reaches the opposite wall in the measurement room      34                    

4.13.7  First Conclusions 

        35 

4.14  Measurements with the basic wall and secondary wall placement 2    
4.14.1  Results related to measurement placement 2 
4.14.2  First conclusions 

                     36 
                                               37 
                                                                                     37 

4.15  Measurements with the basic wall and secondary wall placement 3    
4.15.1  Results related to measurement placement 3 
4.15.2  First conclusions 

                     37 
        38 
        39 

4.16 
 Silencer 
4.16.1   Primary silencer 

        40 
        40 

3 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
         
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
       
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
       
 
 
 
 
 
 
 
 
 
 
       
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
                     
 
 
 
 
 
 
 
 
  
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
4.16.2   Pipe jacketing    
4.16.3   Sound barriers  
4.16.4   FEM calculation of pipe vibrations 
4.16.5   Sound barrier design, improved model for pipe vibrations 
4.16.6   Sound level reduction by sound barrier  
4.16.7   Secondary silencer I 
4.16.8   Further examination of the results 
4.16.9   Secondary silencer type II 
4.16.9.1 Wall with anti-drum tape on both panel inner sides  
4.16.9.2 Wall with anti-drum tape between the panels in the wall side facing the  
              measurement  room  
        47 
4.16.9.3 Wall with impact sound foil between the panels facing the measurement room                        47 
        48 
4.16.9.4 Wall like 4.15.3 but additionally screwed  
        48 
4.16.9.5 Wall with acoustic foam foil between the panels facing the measurement room   
        48 
4.16.9.6 Wall W2F partition layer  
        48  
4.16.9.7 Wall W2F with split boards  
        48 
4.16.9.8 Wall W2F with split boards, filled  
        48 
4.16.9.9 Results summary 
        49 
4.16.10  First conclusions 

        40 
        41 
        41 
        41 
        43 
        44 
        45 
        47 
        47 

4.17 

 Real fittings, non-classified 

5. 

6. 

 Final Conclusions 

 Exploitation and impact of the research results 

Figures  

Tables   

List of Figures  

List of Tables   

List of Acronyms and Abbreviations   

List of References 

Appendix 1  Quantities 

Appendix 2  Walls Arrangements 

Appendix 3  Advanced Plumbing Solutions 

Appendix 4   Guidelines  

        50 

        51 

        53 

        55 

        97 

                   111 

                   115 

                   117 

                   119 

      129 

      131 

      141 

      147 

4 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
       
 
 
 
 
 
 
 
 
 
 
 
 
 
       
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
       
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
Final Summary 

The target of the project was the analysis of the sound propagation initiated by fittings in light gauge 
walls and the design of measures being able to reduce the sound generated in the adjacent rooms. 

Labs 

The labs for the measurement of the fitting noise in the project consist of a measurement or microphone 
room (M) where the sound is measured at three different positions. 
One  wall  of  the  microphone  room  is  the  light  gauge  wall,  whose  properties  have  to  be  analysed  and 
improved during the project. The side of the light gauge wall facing the measurement room is bare. 
The opposite side of the light gauge wall bears the pipe and therefore it is an element of the exciting 
system. 
The  room  where  the  pipe  is  installed  and  among  other  things  attached  to  the  test  wall  is  called  the 
mounting or pipe room (P) because every assembling is carried out there.  

The standard EN ISO 38221 

The  experimental  work  follows  the  EN  ISO  38221  “Laboratory  tests  on  noise  emission  from 
applications  and  equipment  used  in  water  supply  installation”  because  it  defines  the  measurement 
process as a whole. 
So different labs working according to it should reach comparable performances. 
The Installation Noise Standard (INS) prescribed in the EN ISO 38221 as noise source has been also 
used in the project as “reference fitting”. 
With an A-corrected equivalent sound level of LAeq = 46.8 dB it is a very strong noise source. 
The pipe excited by the vibrations of the INS has been clamped to the board by four clamps at irregular 
distances according to the EN ISO 38221. 

The philosophy of the standard is to compare any fitting with the strongest noise source, the INS and to 
determine how much better the fitting is in relation to the INS. In this manner the measured value can 
be established independently from the peculiarity of the measurement arrangement. 

The standard uses a heavy massive stonewall of an areal density between 100 kgm-2 and 250 kgm-2 as 
the  propagating  medium.  Because  a  light  gauge  wall  is  a  complex  arrangement  of  different  elements 
and materials with total areal densities of 10-25 kgm-2 some different procedures in derogation  from the 
EN ISO 3822 were necessary.  
They concern mainly the manner of fastening the pipe to the wall, which has been finally fastened only 
on one side of the light gauge wall. 
Because the target of the project was to analyse the sound propagation through the arrangement, it was 
the unique right fastening possibility reflecting the dry lining practice. 

Board materials 

Gypsum  board  (GB)  is  the  predominant  material  in  dry  lining  because  it  is  cheap,  light  but  with 
sufficient  strength  for  the  most  requirements.  Gypsum  fibreboard  (GF)  follows  at  distance  due  to  its 
higher static properties but also nearly double bulk density and therefore weight making it less suitable 
for handicrafts.  
Last  but  not  least  the  oriented  strand  board  (OSB)  is  coming  up.  It  has  similar  static  properties  like 
gypsum fibreboard but the density of gypsum board and a higher anisotropy. 
From there the gypsum board and gypsum fibreboard were the main actors in the project whereas OSB 
was focussed on special applications in connection with bearing walls. 
Due  to  the  fabrication  process  the  minimal  thickness  of  OSB  amounts  to  19  mm.  GB  and  GF  are 
deliverable with thickness 10 and 12,5 mm. 

5 
 
 
 
 
 
 
 
 
 
 
 
 
 
Walls 

In the following the list of wall variants used is given (see Annex Wall Arrangements) 

- 

- 

- 

- 

- 

- 

- 

Single  planked  wall,  GB  or  GF,(thickness  12,5  mm),  C-profiles  conventional,  U-profiles 
conventional, acronym W1G (G for gypsum board) or W1F (F for gypsum fibreboard) 
Double  planked  wall  of  same  material,  GB  or  GF,  (thickness  12,5mm,  10  mm),  C-profiles 
conventional, U-profiles conventional, acronym W2G or W2F 
Single  planked  airborne  sound  wall,  GB  or  GF,    (thickness  12,5  mm),  C-profiles  split,  U-
profiles conventional, acronym W3G or W3F 
Double planked airborne sound wall of same material, GB or GF, (thickness 12,5 mm+10mm),  
C-profiles split, U-profiles conventional, acronym W4G or W4F 
One side double planked wall of same material, GB or GF ,(thickness 12,5mm+10 mm), other 
side  single  planked  OSB  (thickness  19  mm)  bearing  wall,  C-profiles  conventional,  U-profiles 
conventional,, acronym W5G or W5F 
One  side  double  planked  wallof  same  material,  GB  or  F  ,(thickness  12,5mm+10  mm),  other 
side OSB+ thermal insulation polystyrene (100 mm) 
 bearing  wall,  C-profiles  conventional, 
U-profiles conventional, acronym W6G or W6F 
Double  planked  wall  of  same  material,  G  or  F,  (thickness  12,5mm+10  mm),  C-profile 
conventional,  U-profile  conventional,  earth  quake  version  (Turkish  norm),  bearing  wall,  
acronym W9G or W9F 

Further acronyms have been introduced for different supplementary trials to avoid some confusion, so 

- 

Trials with secondary silencer W8G or W8F using really a wall W9G or W9F 

The  non-bearing  walls  used  members  with  the  usual  thickness  of  0,6  mm,  the  bearing  walls  W5F 
(W5G), W6F (W6G) and W9F of 1,5 mm. 

Placements 

Four different wall placements were taken into consideration 

- 
- 

- 

- 

and 

perpendicular 

(3750x2500  mm) 

Main wall alone (widthxheight: 3750x2500 mm) (acronym PL  1) 
Main  wall 
secondary  wall 
(widthxheight:2500x2500 mm). The primary wall bears the pipe. The secondary wall is passive 
and stays in the microphone room (acronym PL 2) 
The  secondary  wall  bears  the  pipe  and  stays  in  the  mounting  room  (pipe  side  room).  It  is 
fastened perpendicular to the passive main wall (acronym PL 3). 
The main wall is perpendicular to the measurement orifice. It stays half in the mounting room 
and half in the measurement room. The pipe is attached to the part of the main wall staying in 
the  mounting  room.  The  orifice  is  closed  by  a  passive  secondary  wall  of  3750x2500  mm 
(acronym PL 4).  

fastened 

The fourth version was rejected in the course of the project because the experimental results established 
a similarity to PL 2 with the same conceptual weakness. The introduction of a secondary wall into the 
measurement room changes its acoustic conditions in a very drastic manner, so that the results are rather 
incomprehensible. 

Connections 

In  addition  to  the  listed  walls  and  placements  three  versions  of  wall  connections  between  the  main 
(MW) and the secondary wall (SW) were used.  

- 
- 

SW screwed to a C-profile of the MW (hard fastening),  acronym A 
SW  screwed  to  a  C-profile  of  the  MW  .  Elastic  layer  between  the  walls  (Soft  fastening),  
acronym C 

6 
 
 
 
 
 
 
 
 
 
 
 
 
 
- 

SW screwed aside of a C-profile on the panel of the MW (hard fastening), acronym D 

Because  the  C-profiles  are  arranged  in  a  regular  grid  of  625  mm  according  to  the  standardised 
dimensions  of  the  panel  of  1250x2500  mm  the  fastening  of  the  secondary  walls  on  C-profiles 
guarantees a regular flawless, simple and fast mounting of the walls. 

To keep the number of variants reasonable the same walls were fastened together (for example single 
planked wall with single planked wall, double planked wall with double planked wall  etc.) although in 
practice the compulsion of economy  introduces a broader palette of combinations. 

Measurements PL 1 

The placement 1 using the main wall alone was the most important arrangement for the insight into the 
complex feature of vibrations of light gauge walls.  
With it the measurement conditions for light gauge walls differing from the EN ISO 38221 have been 
worked out. 
Due to its simple straight structure it was predestined for comparisons between the numeric simulation 
by FEM and the measurement results. 
The  first  key  measurements  are  related  to  the  cross-reference  measurement  gypsum  board  versus 
gypsum  fibreboard  to  be  performed  in  both  labs  to  guarantee  an  objective  comparison  between  both 
materials using the basic wall W1G and W1F. 

In result of the measurements gypsum board produces a slightly higher sound level of 1,2 dB. Keeping 
in mind that people cannot distinguish sound differences lower than 1 dB we can establish that gypsum 
board  and  gypsum  fibreboard  have  similar  dynamical  behaviour  and  therefore  generate  comparable 
sound  levels  despite  of  rather  different  static  properties  (Egypsum,xx/yy  =  2800/2200  Nmm-2  versus 
Efibreboard,xx/yy = 3800/3800 Nmm-2 and gypsum = 680 kgm-3 versus fibreboard = 1150 kgm-3). 

In the following only the results for gypsum fibreboard are reported. 

The very shortened performances for the basic wall and different planking are put together in table 1. 

Walls 
LAeq [dB] 
INS LAeq = 46,8 
dB 

W1F-11  W2F-10 W3F-10 W4F-10 W5F-10 W6F-10  W9F-10
41,5 

44,6 

47,3 

48,9 

46,8 

42,3 

44,7 

0 

-4,5 

-2,2 

-5,3 

0,5 

2,1 

-2,1 

Table 1 Single Walls, no secondary wall connection 

In the first line the measured A-corrected absolute values are reported. WF5-10, W6F-10 and WF-9 are 
bearing walls with a member thickness of 1,5 mm, so the dynamical stiffness of their skeleton is round 
16 times higher than that of the non-bearing walls with a member thickness of 0.6 mm.  

In  the  second  line  the  interpretation  philosophy  of  the  EN  ISO  38221  is  applied.  This  means  a  noise 
source with a sound level of X dB forcing the water feeding circuit to vibrate generates a sound level in 
an adjacent room, which is weakened by the values of line two in dependence of the nature of the wall. 

The most surprising result of table 1 is that the double-planked wall with split C-profiles (W4F-10) is 
not really better than the double-planked conventional  wall (W2F-10) . The single planked wall with 
split C-profile (W3F-10) is even worse than the W2F-10. 

This means that the vibration energy transport from one wall side to the other runs mainly over the top 
and bottom U-profiles and not face-to-face over the C-profiles (in the case of non-split C-Profiles). The 
later  direct  measurement  of  the  vibrations  of  the  profiles  showed  that  it  runs  mainly  over  the  top  U-
profile. Due to the compression of the elastic subsoil under the bottom U-profile by the weight of the 
wall the transport across this profile is negligible. 

7 
 
 
 
 
 
 
 
 
 
 
 
 
 
Measurements PL 2 

The next group of trials dealt with the placement 2 (PL 2) and connections A, C, D for the walls W1F-
W9F. 
Here the secondary passive wall is connected to the primary active basic wall (exciter) and stays in the 
measurement (microphone) room. 
Although  the  business  was  long  and  hard  the  results  can  be  resumed  in  one  sentence.  Only  one  wall 
reached a lowering of the input noise level of  – 4,7 dB worth mentioning, the double-planked wall with 
split C-profiles (connections A: -3,9 dB, C: -4,7 dB, D: -4,4 dB). 
The unique favourable knowledge true for all the walls was that the C-connection gives better results 
than the other two ones. 
So  the  grid  implied  by  the  C-profile  distance  can  be  used  with  benefit  if  an  elastic  interlayer  is 
introduced. 
These  results  led  to  the  rejection  of  the  PL  4  because  there  the  active  wall  should  directly  act  in  the 
microphone room and could only be worse. 
The surely most important worsening of the measurement room was that introducing a supplementary 
mass and particularly a new reverberation area of 4/3 the size of the main wall, the acoustic conditions 
of the measurement room had been drastically changed without having been proved before. 

Measurements PL 3 

The third and last group of measurements dealt with the placement 3 and connections A, C, D for the 
walls W1F-W5F. 
In the PL 3 the secondary wall bearing the pipe stays in the mounting room. So the acoustic conditions 
of the measurement room are the same as in the PL 1. 
Changes of the acoustic conditions in the mounting room influence only the airborne sound, which is 
mainly attenuated by the acoustic mineral wool inside of the wall. 

Walls   

W1F - 

LAeqINS 
INS LAeq = 46,8 
dB 

3C  W2F – 3C W3F – 3C W4F – 3C  W5F-3C 
32,7 
-14,1 

30,2 
-16,6 

33,1 
-13,7 

31,7 
-15,1 

33 
-13,8 

Table 2 Walls, placement 3 (PL 3), connection C 

Table  2  gives  only  the  best  results  for  the  best  connection  C.  These  are  the  ultimate  results  even 
reducing the strong noise source INS to whisper. 

FEM-Simulation  

The  very  extensive  FEM-work  has  contributed  essentially  to  the  correct  interpretation  of  the 
experiments.  In  addition  non-planned  vibration  measurements  have  been  introduced  to  have  a 
correspondent experimental method to the FEM-calculations of the vibration parameters. 

In a first step a single module of 1250x2500 mm was calculated. In the further progress of the project 
the calculation of the total wall consisting of three modules with a total of 3750x2500 mm was carried 
out. 

In result of the FEM expertise it became obvious that  

- 

The steel construction doesn’t influence markedly the vibrational behaviour of the panels. 
The panels don’t take notion that they are elements of a steel armed wall but the steel members 
follow their motion slavishly also in their three dimensional complexity. 

8 
 
 
 
 
 
 
 
 
 
 
 
 
In the balance a single planked wall of gypsum/gypsum fibreboard has a weight of 178/234 kg 
in relation to the total weight of the steel members of 40 kg. 
The geometrical stiffness of the gypsum/gypsum fibre board to that of the steel members where 
the  thickness  has  an  influence  in  the  third  power  is  like  as  0,007/0,009  for  non-bearing  walls 
and 0,10/0.14 for bearing walls with a thickness of 1,5 mm. 

The  panels  of  the  single  modules  don’t  vibrate  as  individual  elements.  They  take  on  the 
eigenfrequencies of the total wall of dimension 3750x2500 mm obviously due to the common 
full-length U-profiles. Although the mechanical excitation of the pipe is introduced on the spot 
in every single module the common U-profiles re-arrange the individual behaviour of the single 
boards to an integral whole. 

Pipes are excellent vibrators due to the very high number of possible vibration modes and types 
i.e.  longitudinal,  transversal,  thickness  modes  as  well  as  their  combination,  so  that  there  is 
always a mode, which makes a good match to every constrain. 
Physically the clamps connecting the pipe to the boards at irregular distances as it is required by 
the standard are the constrains introduced into the calculation.  
But the pipe seems to be  capable to pass forward the initial vibration of the INS under every 
boundary condition. 

Only transversal modes of the pipe generate an audible sound. Bows introduced into the feeding 
circuit act like a spring taking over the vibration partly. 
Because every bow design has it own frequency response to the vibrational input it acts like a 
filter suppressing some spectral components of the input spectrum.   
So a family of primary silencers B1-B4 was designed and their response function calculated by 
FEM. 

- 

- 

- 

Silencers 

After  the  three  measurement  campaigns  we  had  one  arrangement  with  very  successful  solutions 
(placement  3)  and  one  arrangement  with  a  weak  improvement  of  the  fitting  noise  reduction  of 
maximally –5,3 dB (placement 1). 
The placement 3 cannot be realised in every house design nor it can be imposed to every customer. 
Therefore  solutions  had  to  be  found  to  reduce  the  vibration  energy  of  the  feeding  circuit  before  it  is 
introduced into the wall by the fastening. The performance of the basic main wall had to be improve by 
additional measures as well because it is an indispensable construction element of every house. 
This is the scope of the so-called silencers. 
Every measure suitable to reduce the sound level of a fitting, which is not a basic construction element 
of the light gauge wall modules, has been called a silencer in the project. 
The basic construction elements are the steel frame, the planking and the mineral wool inside. 

Primary silencers 

A  primary  silencer  is  a  measure  suitable  to  reduce  the  fitting  noise  acting  directly  on  the  feeding 
system, without changing anything in the wall. Therefore its performance is added to that of the wall 
resulting in a higher total improvement of the sound reduction. Primary silencers are 

-  Complete jacketing of the pipe with acoustic foam layer of density 120 kgm-3 
-  Sound barriers 
-  Sound barriers embedded  

The simplest sound barrier B1 is a bow introduced into the feeding circuit. It acts like a spring mainly 
weakening  the  low  frequency  vibrations  of  the  feeding  system.  Because  the  pipe  vibrates  in  every 
direction, further combinations of the barrier B1 have been designed. 
Because the higher configurations of sound barriers consist of further silencers B1 connected in series    
but  in different  directions the  total  reduction  of  the  sound level  is  the  addition of  the  power  of  every 
silencer. 

9 
 
 
 
 
 
 
 
 
 
 
 
By  embedding  the  barrier  into  a  mean  with  high  internal  friction  the  high  frequency  part  of  the 
spectrum, which is not intercepted by the bow is annihilated. 

The performances of the primary silencer is given in the table 3  

LAeq [dB] 
Difference to column 1 [dB] 

Without 
Silencer 
45,1 
0 

Pipe 
Jacketing 
40,3 
-4,8 

Silencer B1 

44,20 
-0,9 

Silencer B1 
embedded 
40,5 
-4,6 

Table 3 
Sound reduction by primary silencer 

Secondary silencers 

A  secondary  silencer  is  a  measure  adding  any  element  to  the  basic  wall.  So  the  wall  design  changes 
from a commercial customary product to a new product.  

We  can  differ  between  two  different  groups  of  measures  carried  out  in  the  project.  So  we  have 
introduced the terms of  “Secondary silencer I” and  “Secondary silencer II”. 

The role of secondary silencers I is to receive vibrational energy from the wall without to give it back to 
the exciter. This is realised by the damping of the energy shifted to the secondary silencer and by the 
mass relation between secondary body and first one. 

When  the  mass  of  the  second  body  is  lower  than  that  of  the  exciter  source  the  energy  from  the 
secondary body is reflected from the heavier body and not transmitted back to the exciter.  

The results were worse than that of the bare reference wall without exception. 

Therefore the secondary silencers of type II take a larger part in the summary.  

Secondary  silencers  of  type  II  are  all  the  measures  working  with  elastic  layers  applied  to  the  boards 
or/and to the frame.  

As one of the most important side effect the trials revealed the peculiarly vibration features of double 
planked walls. 

So the higher performance of double planked walls in comparison to single planked walls doesn’t result 
from the doubling mass. In the basic version only the board adjacent to the steel frame is screwed to the 
members. The second board is only screwed to the first board along the common edges. 

They vibrate independently from another, so that the vibration energy is partitioned between both single 
boards.  

Because the amplitude of the vibration is smaller than 1 µm as the vibration measurements showed, no 
measures must be taken supplementary to improve it. The natural gap between the panels due to every 
imperfection of the manufacturing process is sufficient to allow the free vibration of every board. 

If the two boards are forced to be one board of double mass by extensive fastening the reduction of the 
sound level becomes rather weak (see table 4, column W2F-71 or section 3.16.9.4). 

10 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
Section 

LAeq  [dB] 
INS : 46,8 dB 

W2F-10W2F_50W2F_51W2F_70W2F_71W2F_60W2F_80_n W2F_80GnW2F_90n
3.16.9.8
original 3.16.9.1  3.16.9.2  3.16.9.3 3.16.9.4 3.16.9.5 3.16.9.6 
50,6 
45,1 
3,8 
-1,7 

3.16.9.7 
39,0 
-7,8 

36,2 
-10,6 

42,3 
-4,5 

39,7 
-7,1 

44,0 
-2,8 

46,3 
-0,5 

46,4 
-0,4 

Table 4 
Wall W2F-10, results of secondary silencers 

Table 4 compiles the most important results. 

The numbers in the second line are the section numbers in the final report where the trials are reported. 
In  the  summary  only  the  successful  results  in  bold  letters  and  the  last  one  (W2F_90n)  are  shortly 
commented. 
In the trial W2F_50 stripes of an anti drum layer used in the car and truck body to reduce the impact of 
motor vibrations on the sound level in the cabin have been applied to the inner side of the light gauge 
wall. The positive impact was unexpected high. 
In the W2F_80_n measurement a layer of closed soft polyethylene foam has been intercalated between 
steel frame and boards. This measure was the most successful one. 
In the next trial W2F_80Gn the successful measure used in W2F_80_n has been also used but the part 
of the board bearing the pipe has been cut off from the rest of the wall. 
The target was to isolate the section where the vibration is introduced from the rest of the wall. 
Nevertheless we produced an unexpected deterioration of the best result.  
In the last column the mineral wool inside the wall was removed and the hollow filled with a mean of 
high internal friction. So a wall with a density of 600 kgm-3 comparable to a stonewall was created. It 
should be better than a stonewall due to the additional internal friction. 
But the result is really bad. So the increasing of the inert mass doesn’t seem to be the way to reduce 
mechanical vibrations directly connected to walls.   
In the light of the results we can say that light gauge walls are not simply solutions for poor people but 
present new very impressive positive properties in the question of sound reduction caused by fittings. 

Customary fittings 

The greatest group of customary fittings are the so-called non-classified group without sound level or 
flow limitation (for example 15 l/min). 

The EN ISO 38221 admits pressures up to 5 bar and flows of 120 l/min in housings. 
Nevertheless nobody will purchase the cheapest tap if it produces a noise of 45 dB or more. 

INS 

Type A ¾” 

Type B ½” 

l/h 
l/min 
LAeq 

950 
15,83 
42,3 

1080 
18 
26,4 

Table 5  

3360 
56 
38,2 

1080 
18 
32,6 

2880 
48 
45,1 

Sound levels of non-classified customary fittings 

The table 5 links the results of the test of customary taps performed in the project using the basic wall 
W2F. The second column of every fitting type is the sound level for completely open. 
A non-classified ½” tap flow of 25 l/min should produce a sound level of about 36 dB. In comparison 
low noise fittings for 30 dB (group II) are flow limited at 15 l/min to reach the sound level value. The 
trend is moving to limitation of 12 l/min. 

So it is reasonable to set the targeted reduction power of a measure to –6 dB (or higher if wanted) to 
realise a good relation between expenditure and benefit. 

11 
 
 
 
 
  
 
 
 
 
 
 
 
 
 
 
 
 
 
 
The results of the project allow to reduce the sound level of a conventional fitting down to 20 dB and 
therefore  prevent  not  only  concentration  and  learning  disorder  but  also  the  very  disturbing  sleep 
disorder. 

Conclusions 

It  is  possible  to  keep  the  sound  propagation  in  light  gauge  walls  below  30  dB  for  every  customary 
fitting having a sound level lower than that of the Installation Noise Standard (INS).  

Non-classified customary fittings, the most common group, produce a sound level of 36 dB at a flow of 
25 l/min, which is a reasonable but already rather high output (full open up to 45 dB). 

Using  the  results  of  the  project  the  noise  level  can  be  downgraded  in  dependence  of  the  expenditure 
wanted and the wall design to 30 dB by improved basic walls. The project results offer the possibility to 
reduce the input noise level down by –16.8 dB using the palette of wall arrangements. 

Therefore the sound level of a customary non-classified source of 36 dB should be reduced to less than 
20 dB, the sound level of low breathing. 

The reduction doesn’t take any additive effects into account so that principally a lower level comparable 
to that of the external noise of 16 dB can be reached or higher noise level sources used. 

Gypsum  board  and  gypsum  fibreboard  have  comparable  dynamical  properties  concerning  the 
attenuation of fitting induced sound. 

Gypsum board is about +1.2 dB worse than gypsum fibreboard. 

Light gauge walls bearing water-feeding circuits should be double-planked to obtain a marked benefit 
in sound reduction. 

By  integrating  a  primary  silencer  directly  behind  the  fitting  an  additive  effect  of  –4.8  dB  can  be 
reached. 

Exploitation and impact of the research results 

This  is  the  first  systematic  expertise  drawing  the  possibilities  of  noise  reduction  in  light  gauge 
constructions comparable to or better than that in stonewalls environments.  
Therefore their application can start first now. 
The addressees of the results are the firms working in dry lining business. These are the first to be able 
to use the technical and economic potential of the results.  
Generally they are small companies with low engineering potential who look for solutions in the local 
environment.  
So the most effective dissemination way of the results to the firms runs over the regional Chamber of 
Industry  and  Commerce  in  the  national  language  and  as  download  document  in  the  homepage  of  the 
contractors of the project. By now the Internet is the most frequented information source for everybody 
so it should be very probable that the results of the project reach their true users on this way.  
Therefore it is necessary to reproduce the guideline in the national language. 

12 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
1. 

Introduction 

Plumbing  noise  and  its  propagation  finally  through  the  whole  building  is  a  multi-faceted  problem, 
because  quite  different  agents  contribute  to  what  becomes  “an  important  strain  factor  in  the  human 
community”.  
There are three key agents generating the problem to be solved, making necessary to focus the attention 
to three different fields. The first concerns the conditions of the initial excitation of the pipe system and 
basic  solutions  to  reduce  them,  the  second  the  conditions  of  transport  of  the  excitation  energy  by  the 
vibration-ready  pipe  system  into  the  wall  and  finally  the  wall  or  wall  module  vibration  carrying  the 
vibration energy through the whole building.  
The transmission of the excitation of the plumbing system to the building structure depends mainly on 
the  mass  relation  between  the  exciter  and  the  receiver  [8],  [9].  The  larger  the  mass  difference,  the 
smaller  is  the  effect.  This  is  a  condition,  which  is  met  by  classical  stone  or  older  concrete  buildings. 
Plumbing  noise  in  stonewall  dwellings  has  been  analysed  by  different  groups  of  acoustic  science  of 
academic institutions in Europe e.g. [3], [4], [5], [11]. 
To  date  a  normative  work  for  the  evaluation  of  noise  generated  by  fittings  exists  only  for  stonewall 
conditions  where  the  fitting  is  attached  to  a  normalised  pipe  system,  itself  fixed  to  a  stone  or  poured 
concrete wall of an areal density between 100 kgm-2 and 250 kgm-2. 
In comparison the used commercial standard lightweight panels have an areal density of 11.5 to 21.5 
kgm-2, mainly 15 kgm-2. So the use of lightweight systems, in common with many other modern trends, 
counteracts this range of sight.  
In addition the jacketing of outer walls for instance with acoustically hard polystyrene panels as a result 
of the current heat insulation rules contributes to boost the sound level within rooms. 
Therefore this project entered known but virgin soil. 

2. 

Objectives  

This project aims at systematically studying the propagation of sound in light gauge walls generated by 
fitting  noise  following  the  EN  ISO  38221  “Laboratory  tests  on  noise  emission  from  applications  and 
equipment used in water supply installation” using a standardized noise gauge.  
For  the  light  gauge  walls  the  two  most  applied  planking  materials,  the  gypsum  board  (GB)  and  the 
gypsum  fibreboard  (GF)  have  been  mainly  used.  Every  lab  involved  had  to  carry  out  the  full 
measurement  programme  with  one  material.  ISQ  worked  with  the  gypsum  board  whereas  FQZO  has 
performed the measurements with the gypsum fibreboard. 
To  have  an  objective  co-relation  between  the  results  of  the  different  materials  and  labs  some  cross-
measurements with each material should be performed in both labs. 

The project objectives can be summarised in the following items:  

- 

- 
- 
- 

- 

- 

- 

- 

- 

2D  vibration  analysis  by  means  of  the  finite  element  method  (FEM)  for  the  lightweight  steel 
compounds (modules) defined in the test program (variant 1-6) 
2D vibration analysis of pipe design to set the eigenfrequency of the pipe to defined values 
2D vibrations analysis of the same compounds with integrated secondary vibration systems   
Construction of the lightweight dry construction modules (36 for every lab, total 72) including 
one basic earthquake-proof wall element and two new non-coherent wall modules, 
Measurement of fitting noise propagation for six variants of compounds four coupling variants 
of  walls  and  four  arrangements  of  the  noise  gauge  (g1-g4),  according  to  the  test  programme, 
covering a representative cross-section of cases in practice   (total 178) 
Measurement  of  the  propagation  of  fitting  noise  in  compounds  with  a  secondary  vibration 
system  (silencer)  for  the  wall  variants  1-5,  two  silencer  variants  and  one  arrangement  of  the 
noise gauge (g1) 
Measurement of the propagation of fitting noise in classical pipes without and with eddy control 
body 
Measurement of the propagation of fitting noise using new pipe designs for the wall variants 1-
5 and one arrangement of the noise gauge (g1) 
Design rules for low cost lightweight compounds for fitting noise propagation  30 dB 

13 
 
 
 
 
 
 
3. 

Comparison of initially planned activities and work accomplished 

The item of secondary silencers has been redefined because both the numeric calculations as well as the 
experiments  showed  that  there  is  no  incoherent  vibration  between  the  two  opposite  faces  of  a  light 
gauge module. Therefore an annihilation of vibration energy by connecting the faces inside the module 
doesn’t take place. 
In addition the first group of measurements showed that the vibrational energy introduced by the pipe 
via the four clamps into the board is transported over the top (mainly) and the bottom U-profile whereas 
the face-to-face transport by the C-profiles is negligible. 
This unexpected result made the search for new ways in the matter of secondary silencers necessary.  
Nevertheless  the  extended  section  secondary  silencers  in  its  completion  has  delivered  the  key 
understanding of how light gauge walls vibrate really and offers good solutions for the improvement of 
sound  level  reduction.  The  most  important  supplementary  benefit  results  in  the  better  feasibility  in 
practice than the original one. 
This  experience  generated  an  intensive  and  extensive  search  for  other  solutions  suitable  to  reach  the 
targeted sound level limit of 30 dB required by the law. 
The  number  of  wall  connections  has  been  reduced  to  three  because  like  it  can  betaken  from  the 
appendix Wall arrangements the difference between the variants B and C consisted in the sealing of 
the small joint between the two perpendicular walls. In both variants the elastic stripe between the walls 
is the dominant factor for the improvement of the arrangement.  
In the variants A and D where the two walls are hard but differently connected. Drywall filler has been 
used. 
In the B and C version drywall filler versus elastic seal was the unique difference. 
So the withdrawal of the variant B has no impact on the results of the project.  
In the light of the bad results of the placement 2 where a secondary perpendicular wall has been placed 
in  the  measurement  room,  the  placement  4  has  been  abandoned.  Placement  4  was  another  variant  of 
placement  2  having  also  a  part  of  the  wall  placed  in  the  measurement  room  (see  Appendix  Wall 
Arrangements).  Obviously  the  introduction  of  a  secondary  wall  into  the  small  but  in  relation  to  the 
requirement of the EN ISO 38221 concurring measuring room caused an unexpected drastic change of 
the acoustic conditions. 
Due  to  the  secondary  wall  a  reverberation  surface  4/3  larger  than  the  total  area  of  the  basic  wall  has 
been supplementary introduced heavy disturbing the basic geometry of the measurement room. 
The  measurement  of  the  propagation of  fitting  noise  in  compounds  with  secondary  vibration  systems 
has been reduced to the wall W2F from the point of view of practical reasons 
Wall variant 1 transmits the vibration energy 1:1 through the wall. Walls 3 and 4 are special walls with 
split C-profiles and therefore more expensive than the straight basic walls 1 and 2.  
Walls 5 and 6 use OSB a material for niche applications. 
So  it  made  sense  to  focus  the  improvement  on  the  wall  materials  with  the  highest  acceptance  by  the 
customers, the gypsum board and the gypsum fibreboard.   
In fact five of the eight variants delivered unsatisfactory performances but in so far as they lighten the 
basic transportation of vibrational energy by light gauge walls they were useful. 
Therefore  one  wall  variant  and  eight  secondary  silencer  versions  were  used  versus  planned  five  wall 
versions and two silencers. 
The  propagation  of  fitting  noise  by  new  pipe  design  (primary  silencer)  was  reduced  to  one  wall  with 
generic bad sound performance, the earthquake version for bearing wall. 
Because  the  complete  annihilation  of  the  mechanical  vibration  was  reached  with  a  sound  barrier  B1 
embedded in a granular medium with high internal friction no further trials were necessary.  
The  point  of eddy  current control  consisting  in  introducing  a battery of  small  diameter  pipes  into  the 
feeding pipe so that the whirl were atomised there was rejected due to two reasons. 
The  component  must  be  constructed  in  stainless  steel  and  therefore  it  was  expensive.  Its  introduction 
into the main circuit was difficult. 
At  the  time  at  which  the  realisation  of  this  point  became  concrete  the  performance  of  the  secondary 
silencers reached already its best value of – 10,6 dB. 
Together with the additive power of the primary silencer of –4,5 dB, silencers reached a total reduction 
of fitting noise of  –15,1 dB. 

14 
 
 
 
Meanwhile the best wall design without silencers of any kind reached –16,6 dB sound level reduction. 
If we put these values in relation to the noise of a non-classified ½”valve delivering 25 l/min at 3 bar of 
36 dB we reached already a residual noise in the adjacent room of 20 dB or low breathing. 
Therefore further reductions of sound raising the price of a good value product seemed very academic.  
A  supplementary  non-planned  work  has  been  implied  by  the  necessity  to  have  an  objective  and 
quantitative  assignment  of  the  results  of  the  FEM-calculation  and  the  sound  measurement  due  to  the 
vibration of the panels of the modules. 
Therefore  the  direct  measurement  of  the  mechanical  vibration  of  the  different  elements  of  the  sound 
generating system seemed to be mandatory at a certain completion of the FEM-work. 
The supplementary work performed by UPM and FQZO was implied by a lot of important questions in 
connection with the confidence of some results. 
The second non-planned additionally work concerned the simulation of the possible generation of room 
modes in the mounting room performed by UPM and their experimental validation by FQZO. 
This  was  a  trial  to  check  the  questions  if  the  always-higher  sound  level  measured  by  FQZO  in 
comparison to that of ISQ came from high intensity room modes in the mounting room of FQZO. 
In  the  ISQ  facility  the  sound  produced  outside  the  measurement  room  vanishes  in  an  “infinite” 
surrounding. 
The  mounting  room  in  the  FQZO  lab  has  no  oblique  walls  (only  the  measurement  room)  so  that  it 
should be possible that such phenomena appear. 
Fortunately  the  simulation  as  well  as  the  difficult  experimental  measurements  didn’t  reveal  the 
existence of high sound level room modes. 
Despite  of  some  changes  in  the  original  planning  not  less  work  has  been  done.  FQZO  and  UPM 
extended  their  manpower  well  over  the  budgeted  plan  using  only  their  own  resources  to  obtain  these 
convincing values. 
ISQ and ArcelorMittal Construccion remained within the planned budget. 

4. 

Description of activities and discussion 

4.1 

Getting started 

If a creative designer has not conceived a steel house, it looks like a quite ordinary stone house1, as it 
can be seen in Fig. 1. 
The inner structure of the house is built by a steel skeleton of thin steel profiles (see Fig. 2), planked 
with panels of suitable material. The steel profiles are usually hot dip galvanized to avoid a long-term 
degradation by corrosion. 
The  distance  between  the  vertical  profiles  is  imposed  by  the  standardized  size  of  the  panels  of  WxH 
(Width x Height) of usually 1.25x2.50 m. 
A  planking  board  not  only  defines  the  spacing  of  the  construction  but  actually  a  geometrical  and 
mechanical entity, which is called module in the following. 
This is due to the fact, that the mass of the boards in comparison with that of the steel is rather dominant 
within the board area. 
Therefore it is to expect that some dynamical properties especially all the items concerning vibrations 
and sound transportation are mainly governed by the mechanical properties of the planking material. 
The longest light gauge wall used in the project consists of three modules armed by seven vertical C-
profiles  according  to  Fig.  3.  The  doted  ellipse  suggests  that  the  further  screw  connection  can  be 
removed if there is no perpendicular wall behind. 
The  distance  between  the  vertical  C-profiles  is  here  0.6125  m  like  in  the  show  house,  the  half  of  the 
width of the board, to obtain a rigid centre of the plate against free bending of the ensemble. 
The C-profiles are linked by one upper and one bottom U-profile having the length of the total wall i.e. 
3x1.25 m = 3.75 m for better rigidity of the ensemble. 
The  statics  of  a  steel  house  is  closely  related  to  the  steel  skeleton  and  here  especially  to  the  statics 
property of the C-profiles. 

1 Show Steel House in Eisenhüttenstadt, Germany, constructed by FQZO, 2003 

15 
 
 
 
 
 
 
                                                 
4.2  Members  

Because of the dominant role of the steel profiles for the statics, they are ruled in the standard DIN EN 
14195 

 DIN EN 14195  

Metal framing components for gypsum plasterboard systems 
Definition, requirements and test methods 

Therefore it was natural to construct the modules for the sound measurements according to the standard 
mentioned above. 
Table 1 reports the specification of the member palette used. 
For the non-bearing wall members a usual thickness of 0,6 mm fulfils already the statics conditions. For 
bearing  wall  members  a  customary  thickness  of  1,5  mm  was  used.  All  members  were  hot  dip 
galvanised. 

4.3 

Planking Material 

After  the  steel  skeleton  has  been  erected  it  is  planked  with  panels  of  suitable  material.  Without  a 
supplementary  reinforcement  of  the  steel  frame  like  it  is  necessary  in  an  earthquake  version,  the 
planking alone prevents the shear displacement of the frame.  
Therefore it fulfils a secondary but important statics function too. Nevertheless the requirements on the 
mechanical properties of the boards are less stringent so that rather different materials can be used. 
The mostly used material in dry lining is indeed the gypsum board. 
The preference for this material goes back to lower price in comparison to the other materials. The low 
density  and  therefore  a  weight  of  the  half  of  that  of  gypsum  fibreboard  makes  it  also  preferable  for 
handling. 
Finally using adequate dry lining dowels every fastening in a gypsum board can bear 40-kilogramme-
weight force load safely. This is sufficient for all domestic cases. Therefore gypsum board is not simply 
a solution for poor people. 
Though  the  low  density  and  weight  of  gypsum  panels  (and  low  price)  make  them  favourable  in  the 
mounting  period,  some  static  conditions  are  better  fulfilled  by  materials  with  higher  stiffness  and 
mechanical strength like gypsum fibreboard.  
Anyway the nearly double weight of gypsum fibreboard introduces more comfort into the day. 
Finally it is suitable to be able to close a door without making the whole house vibrate. 
The third board material used is OSB (Oriented-Strand-Board). In relation to the mechanical properties 
of the other materials it is a mixture of gypsum board (density), gypsum fibreboard (Young module in 
the principal axis) but has a stronger anisotropy than gypsum board.  
So the main attention to materials in the project was focussed on gypsum board and gypsum fibreboard 
whereas OSB related to applications in connection with bearing walls.  
Table 2 gives an overview about the mechanical parameters of gypsum board and gypsum fibreboard as 
well as the different mass contribution of the further elements of the wall subsystem.  
Density  and  Young  module  of  gypsum  board  and  gypsum  fibreboard  differ  respectively  by  32%  and 
36%  but  the  so-called  areal  density,  the  weight  of  the  wall  divided  by  its  area  finally  differs  only by 
about 20%. 
On  the  other  hand  if  we  assume  that  the  uncoupled  mineral  wool  doesn’t  participate  to  the  vibration 
mass  and  take  only  boards  and  steel  mass  into  account  then  the  difference  between  fibreboard  and 
gypsum amounts to 26% for single and 28% for double planking. 
Table 3 compiles the mechanical properties required for the simulation work for all the materials. 

4.4 

Filling Materials 

A wall or module consisting only of a steel frame and planking sheets doesn’t fulfil the requirements of 
thermal and/or sound insulation. 
This functionality is introduced first by filling the space between the planking with mineral wool with 
different properties. 

16 
 
 
 
  
 
 
 
 
 
 
 
 
In relation with the thermal insulation of the outer walls the mineral wool must have a low density to 
provide a high number of cavities filled with air, which is a very bad thermal conductor. 
As it can be seen in Fig. 4 the inner space of the modules of the show house is completely filled with 
light mineral wool. 
In  the  case  of  the  prevention  of  airborne  transmission  through  the  wall  a  high  mass  mineral  wool  is 
required 
The  mineral  wool  used  in  the  project  is  the  Rockfeu-E520  with  a  mass  density  of  120  kg/m3  from 
Rockwool. It has a good sound absorption coefficient of around 0,90 nearly constant between 250-4000 
Hz. 
The  thickness  was  taken  to  90  mm  in  comparison  to  the  web  width  of  100  mm  to  avoid  a  tight 
mechanical  contact  between  the  wool  and  panels.  So  the  transmission  of  sound  vibration  by  simple 
mechanical connection between panel and wool was prevented 

4.5  Modules, completed 

It should be remembered that the board, single or double planked defines the so-called wall module due 
to its dominant mass in comparison with that of the steel frame. 
Because the heavy mineral wool damping the airborne sound should not have a tight mechanical contact 
with the planking to avoid the direct vibration transportation of sound it doesn’t influence the already 
mentioned relations in respect to the vibrational properties of the wall. 
The usual module for private area (see Fig. 5, left) consists of three vertical C-profiles, here with a web 
of 100 mm, linked by one top and one bottom horizontal U-profile. It is single or double planked. 
For  better  airborne  insulation,  for  instance  in  public  structures  like  hotels  the  second  module  (Fig.  5, 
right) is often used, where the C-profiles are replaced by twice C-profiles of half width. 
Only the mechanical connection between the two opposite panel sides over the U-profiles remains, so 
that  airborne  sound  must  take  the  way  mainly  through  the  acoustic  mineral  wool,  where  it  is 
annihilated. 
Like already mentioned dry lining modules have a grid size of commonly 1.25x2.5 m according to the 
standardized panel size. 
Therefore  longer  assemblages  reflect  the  grid  size  of  the  panels,  but  have  one  common  skeleton 
member to secure the rigidity of the whole construction. 
The  practice  of  house  construction  contains  more  complex  assemblages  characterised  by  corners  and 
connections  between  perpendicular  walls.  The  kind  of  connections  between  the  joints  is  rather 
important for the amount of vibration transported through the whole construction.    
That is the reason why the measurement of a construction consisting of two perpendicular walls like it 
can be seen in Fig. 6 has taken a wide place within the measurement programme. 
Last but not least an earthquake version has been added to the programme (see Fig. 7). The main reason 
for the failure of a wall by earthquake is due to strong shear oscillations the house performs due to its 
inertia when the ground moves under it. 
Supplementary steel stripes without static function hinder the main shear displacement. Due to the new 
mechanical vibration paths some reinforcement of sound propagation can come into being. 

4.6  

Fitting noise  

The complex features of noise generation by fittings have been explained at the beginning of the report.  
Nevertheless it makes sense to compile all the different important items in the simple draft of Fig. 8. 
A fitting symbolized by its vibration activity (green arrows) sets the feeding pipe in vibration. 
Because  the  pipe  is  rigidly  clamped  to  one  side  of  the  light  gauge  wall,  this  wall  side  itself  is  set  in 
primary vibrations.  
The  wall  side  acts  as  a  huge  loudspeaker  membrane  and  generates  a  strong  sound  level  in  the  room 
where the fitting is acting. In the following this room is called the pipe or mounting room. 
This  sound  is  reflected  by  the  surrounding,  comes  back  (doted  blue  arrows)  as  airborne  sound  to  the 
wall and passes through it to the adjacent left room. 

Because this room is the room where the resultant sound level is measured by microphones it is called 
the measurement or microphone room. 

17 
 
 
 
 
 
Via the steel skeleton joining the two opposite boards the wall put in vibration by the pipe transports a 
large part of the generated vibration energy to the wall in the microphone room, which becomes itself a 
secondary loudspeaker membrane.  
From the point of view of elemental mechanics it is the problem of two coupled harmonic oscillators  
(see Fig. 9) where the vibrating pipe is the eccentric motor forcing the first oscillator, the wall bearing 
the  pipe  (WallP)  to  perform  harmonic  vibrations  which  are  transported  via  the  coupling  spring  (steel 
skeleton) to the second harmonic oscillator the wall facing to the microphone room (WallM). 

4.7  

Sound and noise level, quantities 

The legislative body requires keeping some values for the so-called equivalent total continuous sound 
level Leq. 
Sound  of  frequency  m  is  generated  by  harmonic  fluctuations  of  air  pressure  p(m,t)  also  at  the 
frequency m. Generally the amplitude of the pressure fluctuation doesn’t remain constant in time, so it 
is necessary to introduce the variable time “t” to describe any sound event correctly.  
In the acoustics it is usual to use sound levels in decibel [dB], which are the common logarithmic ratio 
of the pressure fluctuation square p2(,t) to a reference value square p0

2 according to  

                 p2(,t) 
Lp(,t)  = 10log  

2
                  p0

[dB]. 

     (1) 

p0 is the audibility threshold which has a historical value of 20 µPa at the historically fixed frequency of 
1000 Hz.  

The equivalent continuous sound level Lp() is the time average of a sound event according to Eq. (1) 
                                                         T
                              1 
Leq() 
                                               T 
                                                       0 
The integrand is nothing else than p2(,t)/ p0

 = 10log     10 

   [dB]   

   Lp(,t)/10 

   dt  

2. 

     (2) 

So every time dependent sound event is made equivalent to a sound source of constant loudness in time 
whose sound level is given by Eq. 2. 

Finally the equivalent continuous total sound level is the sum total of the equivalent continuous sound 
level  Leq(i)  measured  in  a  frequency  interval  or  band    (octave  or  one-third-octave  interval)  with  the 
centre frequency I in accordance with Eq. 3. 

                       n 
  
Leq = 10 log     10Leq(i)/10 
                     i=0   

   [dB]   

     (3) 

n is the number of frequency bands i measured.                                                    

The sum total over all audible frequencies is the most redundant characteristic for the sound level of a 
source. 
Therefore  sound  events  of  different  nature  like  music,  conversation,  intermittent  traffic  noise  or  the 
measured  fitting  noise  in  this  project  are  put  down  to  one  equivalent  quantity,  the  equivalent  sound 
level. 
The positive consequence of this philosophy is that no different sound level limits must be established 
for different sound or noise sources. 
So the required limit for the fitting noise level is the same than that for airborne sound namely 30 dB. 
Because the human ear has a different sensitiveness to sound in dependence on frequency a correction 
curve must be added to the physical sound level measured to evaluate the real impact on human ear. 

18 
 
 
 
 
 
 
 
 
 
 
 
 
     
 
 
 
 
 
 
 
 
 
 
 
 
 
   
 
 
 
 
 
 
 
So the noise disturbing human wellbeing is not the noise as it is but the frequency range of the noise he 
can hear. 
This is usually characterised by the so-called A-weighting curve (see Fig. 10), which is simply added to 
the sound level output of the technical receiver. 
So the A-corrected equivalent continuous sound level is given by 

LA,eq(m)  = Leq(m)+A(m) 

                 (4) 

and the equivalent continuous total sound level by  
              M 
LA,eq =   10log10    exp10( LA,eq(m)/10)   
             m=1      
Because measurements of sound levels always take place in a surrounding producing accidental noise, 
the  so-called  (total)  external  noise  (EN),  the  sound  level  produced  by  external  noise  LEN  is  always 
added to the sound level LFN of the fitting noise FN wanted to be measured. 
So we measure always a resultant common sound level LCS according to 

     (5) 

LCS =  10log10 {10 LEN/10 + 10 LFN/10 } 

     (6) 

How the standard stresses LEN must be at least 6 dB lower than the measured resultant sound level LCS 
preferably better than 15 dB. 

If  the  difference  of  the  LCS  to  the  LEN  is  lower  than  15  dB  but  higher  than  6  dB  a  correction  to  the 
measured sound level has to be introduced in accordance with 

L = 10 log(10LCS/10 dB – 10LEN/10 dB) dB 

This measure is due to the very simple reflection that  

LCS = 10log10 {10 LEN/10 + 10 LFN/10 }  10log10 {10 LFN/10} = LFN   

if LEN is about 15 dB and less than LEN.  

     (7) 

     (8) 

2 remains valid. 

Although it seems to be a rule from the non-computer time it brings the good message that the standard 
doesn’t  put  in  question  the  validity  of  measurements  done  under  bad  conditions  because  the  linear 
superposition of p2/p0
Fig.  11  shows  the  placement  of  that  what  30  dB  plumbing  noise  really  is  on  the  scale  of  disturbing 
sound level. 
It can be noted that a plumbing noise level of 30 dB is a very ambitious target nobody wants to reach if 
it had not been required by the legislator. 
A peculiarity of human but also of animal’s attention is related to the fact that low level sound can be 
more  distracting  than  loud  sound  mainly  if  it  contains  information,  which  can  be  important  for  the 
listener. 
That  is  the  reason  why  learning  and  concentration  disorder  according  to  Fig.  11  starts  at  really  low 
sound levels, which are not disturbing in the sense of loudness. 
So the strict requirement for low sound level limits becomes understandable. 

4.8 

Basic experimental arrangement 

How it has been already stressed in the introduction, up to now there is no standard for the classification 
of appliance noise in connection with light gauge modules. 

Nevertheless many standards concerning different aspects of the matter were very useful concerning the 
design of the modules, the revamping of the acoustic labs as well as the method of measurement and 
evaluation. 

DIN EN 621672-1 Electro acoustics sound level meters Part 1: Specifications 

19 
 
 
 
 
 
 
 
 
 
 
 
 
 
                 
                           
 
 
 
 
    
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
DIN EN ISO 717-1 Rating of sound insulation in buildings and of building elements Part 1 Airborne 
sound insulation 
DIN EN ISO 140-3 Acoustics measurement of sound insulation in buildings and of buildings elements 
Part 3. Laboratory measurements of airborne sound insulation of building elements 
DIN 45641 Averaging of sound levels 
EN  ISO  10052  Acoustics  field  measurements  of  airborne  and  impact  sound  insulation  and  of  service 
equipment sound- Survey method 
EN  ISO  3822-1  Acoustics  laboratory  tests  on  noise  emission  from  appliances  and  equipment  used  in 
water supply installations Part 1 : Method of measurement 

The EN ISO 3822-1 became the most important paper for the adaptation and design of the acoustic labs 
to the new task.  
The test room must be restructured for the measurement of the low noise emission from appliances and 
equipment used in water supply installations. For this purpose an aperture for the measuring walls with 
the dimensions of 3,85 m x 2,6 m (see Fig. 12 and Fig. 14) was introduced.  
A  soundproofed  wall  with  a  basis  weight  of  210  kg/m²  was  supplementary  erected  between  the 
mounting room and the pump room to reduce disturbing and undesired noise. 
It  had  also  to  bear  the  installation  of  the  measuring  pipe  inclusive  installation  noise  standard  (INS) 
according to DIN EN ISO 3822-1.  
The  aperture,  as  well  as  the  wall  between  the  mounting  area  and  pump  system  were  acoustically 
separated from the whole lab casing by PHONEWELL floor plates. 
Of course the self-sound of the own water-supply installation must be kept away from the test room.  
Some known solutions consist in using expensive low noise pumps. 
Because of the intermittent nature of the noise trials, we preferred to go another way using a pressure 
vessel fed by a standard water pump and a pressure-reducing valve (see Figure 13).  
The vessel was pumped up to 10 bars by the pump, which was turned off after the feeding of the vessel 
was completed. 
So we disposed of approximately 225 l water for every noise measurement trail at a flow pressure of 5 
bars. The available trial time of about ten minutes was comfortably enough to perform correctly every 
experiment. 
The drainage of the water was performed silently and pressureless to the reservoir.  
Picture  13  shows  the  completion  of  the  FQZO-lab  ready  for  measurements.  The  pipe  in  front  of  the 
opening  inducting  the  vibration  into  the  light  gauge  modules  must  be  removed  for  every  new  wall 
arrangement.  
In  the  conception  it  was  planned  to  mount  the  walls  outside  the  lab  and  to  push  them  through  the 
existent chink near to the second pillar in Fig. 12. 
So it had been possible to assemble the modules simultaneously to the measurements in the test room 
and to save a lot of time. 
Despite of the predicate “light” a complete wall single planked weighs 376 and a double planked 610 
kilogramme-weights  and  cannot  be  moved  by  hand.  Due  to  the  short  dimensions  of  the  different 
openings the use of cranes was impossible. 
Past it the complete wall had a size of 3.75x2.75 m2, which is difficult to deal with. 
A hard problem never seen before consisted in the simultaneous acoustical insulation of the wall during 
its  placement  into  the  measurement  orifice.  Indeed  it  was  rather  impossible  because  of  the  small 
distance between wall and orifice edges and the great friction resistance of the acoustic foam stripes to 
slipping. 
Finally all the modules must be assembled inside the test room directly in the orifice, starting with the 
acoustic decoupling of the module edges. 
The  sound  generation  was  provided  by  a  reference  transfer  noise  standard  INS  (Installation  Noise 
Standard), whose description, design and dimensions are ruled in the EN ISO, 3822-1, see Fig. 15. 

It  can  be  understood  as  a  fitting  whose  properties  are  well  defined  and  repeatable  if  the  design  rules 
required by the standard have been observed exactly. It is calibrated with accuracy of 1 dB and of 0.5 
dB for the A-corrected noise level in regard of the reference values of a primary noise standard. 

20 
 
 
Both labs got their INS from the same supplier2, so that there were no doubts about the comparability of 
the quality of the noise generation source. 
Fig. 16 gives the diagram of the A-corrected reference sound noise level the INS delivers as reported in 
the EN ISO, 3822-1 in one-third octave steps. The numeric values are also reported in the table 4 of the 
report. 
With an A-corrected equivalent total sound level of LAeq = 46,8 dB it is a very strong noise source. 
The  philosophy  of  the  standard  consists  in  comparing  any  fitting  with  the  strongest  noise  source,  the 
INS and determining how the fitting is better in relation to the INS. In this manner the measured value 
can be established independently from the peculiarity of the measurement arrangement and lab. 
After all a standard measurement lab is also a peculiar arrangement. 

4.9 

External conditions FQZO and ISQ 

Due to some historical exceptional conditions the FQZO acoustic labs are installed in the former power 
control building of the steel plant, which has been put out of operation ten years ago. 
Placed beside of the main activity area of the plant (see Fig. 17), they benefit from a very low external 
noise level.  
So  the  A-weighted  total  external  noise  amounts  only  to  16  dB,  far  away  for  example  from  the  low 
breathing noise level of 20-25 dB (see Fig. 11). 
For the project the acoustic lab of ISQ had to be erected in a garage of the company open to visitors and 
employees with higher surrounding noise level. (Fig. 18(a) and (b)) of not less than 22 dB. 
Due  to  this  higher  external  noise  level,  which  became  even  higher  yet  when  cars  moved  within  the 
building, the measurements have been performed only in the later evening when the main stream was 
over. 
Nevertheless  the  more  important  measurement  condition  is  the  difference  between  the  external  noise 
LA,EN and the resultant fitting noise LA,CS.  
This difference was very comfortable in the case of the FQZO-lab amounting to round 30 dB as a rule 
in comparison to 12 dB in the ISQ lab. 
Although  the  value  for  the  ISQ-lab  is  rather  lower  than  that  of  FQZO,  from  the  point  of  view  of  the 
background of the 6-15 dB rule of the standard EN ISO 3822-1 it would be enough to obtain correct 
results. 
Further unsatisfactory differences between the absolute values of the sound level between the two labs 
have  been  subject  of  several  common  expertises,  which  revealed  some  mistakes  in  the  measurement 
regime of ISQ.  
Their elimination brought a certain progress but without reaching the level of the FQZO lab. 
Fig.12 and Fig. 19 show the respective drafts of both labs. Because the lab of the ISQ was completed a 
half year later than that of FQZO, it benefited from the realised conception of the first lab and used the 
same measuring strategy. 
This was an advantage for both companies getting comparable arrangements even if there were some 
differences concerning the infrastructure around the essential measurement cell.  
The  soundproofed  rooms  have  nearly  the  same  dimensions.  The  soundproofed  room  of  ISQ  is  more 
oblique so that volume modes are better avoided than in the FQZO case.   
In the FQZO-lab the technical components i.e. pump, pressure vessel and inter-tank are separated from 
the measurement room by the so-called mounting room, so that noise produced by the arrangement are 
better kept away from the measurement room.  
An important parameter, the length of the pipe from the INS to the first clamping which is required to 
be longer than 2 m and shorter than 10 m by the ISO EN 38221 was well fulfilled in the two labs. 

2 Type:  Transfer Standard 
  ID - number    PTB-IGN-0152  
  Manufacturer:  Physikalisch – Technische Bundesanstalt Braunschweig 
  Calibration date: 

14.08.2000 

21 
 
 
 
 
 
 
                                                 
 
4.10 

 What is different from the standard EN ISO 3822-1? 

The  difference  between  the  target  of  the  standard  and  that  of  the  project  is  first  that  the  standard 
evaluates the noise generated by a fitting at the end of the measuring pipe, rigidly clamped to a stone 
wall of prescribed areal density of 100-250 kg/m2. 
In the case of the standard the type of clamping must ensure that the total vibration energy of the pipe 
i.e. of the fitting is taken over by the wall generating the noise recorded in the test room. 
The project deals with the reduction of the noise transmission of this fitting and pipe resonator in a light 
gauge construction. The noise transfer standard prescribed by the ENISO 3822-1 replaces the fitting. 
Fig. 20 shows the transition from the pipe connection to the stonewall according to the standard (first 
sub-picture  right),  the  equivalent  attachment  to  the  light  gauge  wall  also  compliant  to  the  standard 
(centre sub-picture) and the basic attachment in the current project (left sub-picture).  
The  upper  areal  densities  belong  to  the  gypsum  fibre,  the  underneath  to  the  gypsum  panels  of  usual 
thickness. 
The fastening of a pipe on a stonewall generates a vibration of the wall as integral whole and therefore a 
referent full length hard fastening for standard measurements is mandatory  
In the dry lining practice the pipe is always fastened on one side of the module generally twice planked 
for more rigidity. The transmission of the vibration energy to the opposite side is carried out by the C- 
and U-profiles, which define the wall as such. 
Nevertheless first measurements have been performed with the dry lining modules using the fastening 
of the pipe according to the standard as referent maximal noise level generation. 
The  standard  EN  ISO  3822-1  doesn’t  mention  the  airborne  sound  (AS)  the  pipe  radiates  into  the 
mounting room, which is reflected on the walls and passes through the wall to the measurement room.  
Due to the prescribed wall density of 100-250 kg/m2 for the stone wall it should be negligible 
The standard prescribes only the areal density of the wall bearing the pipe producing noise but not the 
sound properties of the surface of the wall. Reflection properties for the wall have not to be defined. 
Finally the fitting generates the airborne sound, so it belongs substantially to the fitting noise without 
producing the awful noise the mechanical connection between pipe and wall generates. 
The  airborne  sound  has  been  measured  supplementary  by  disconnecting  the  pipe  from  the  clamping. 
Indeed it is a bad-done measurement because if the pipe is disconnected from the clamping it vibrates 
with the whole free length. 
So the airborne sound generated is surely different than that of the clamped pipe. 

4.11  Measurement field 

After having cleared the substantial background of the measurement procedure the decisive details for 
successful and repeatable measurements are compiled. 

4.11.1  Vibrational insulation of the test wall 

A rather important matter concerns the vibrational insulation of the light gauge wall to the surrounding 
lab  wall.  To  measure  correctly  the  wall  vibration  induced  by  the  INS  it  is  essential  that  no  vibration 
moves to the lab envelope and disappears undisturbed. 
The  insulation  facing  to  the  floor  is  more  critical  because  the  full  weight  of the  wall  is  acting  on  the 
backing, so it was composed of a four-layer system as it can be seen in Fig. 21.   
The wall was held in the vertical only by a small wood stopper. 
For  the  three  other  sides  an  acoustical  foam  stripe  was  found  as  sufficient  to  prevent  a  vibrational 
transfer loss.  

4.11.2  Microphone positions 

Fig. 22 contains the draft of the measurement or microphone room where the sound level resulting from 
all the arrangements have been measured. 
The positions of the microphone have been established according to the EN ISO 38221, which requires 
sound level measurements at three positions whose differences are not greater than 3 dB. In this case 
the arithmetic average of the three values is allowed. 

22 
 
 
 
 
 
 
  
Because  only  one  microphone  was  available  every  measurement  had  to  be  performed  three  times 
according to the three different microphone positions. 
This  must  be  always  kept  in  mind  because  it  means  that  the  three  measurements  are  not  coherent  in 
time. 
Strictly spoken if a temporal steady condition during the measurement of the sound level in the three 
different positions cannot be realised a correct interpretation of the results is illusory. 

4.11.3  External noise 

The  first  sound  level  measurement  after  the  placement  of  the  test  wall  into  the  orifice  has  been 
completed is dedicated to the measurement of the external noise. 
For this purpose all the gadgets contributing to generate noise related to the fitting noise have to be out 
of work. 
Because  the  test  wall  doesn’t  contribute  to  the  external  noise  it  should  be  irrelevant  if  it  is  already 
situated in the orifice or not or which current planking has been put up. 
Table 5 gives the equivalent continuous total sound level values of the external noise in the FQZO-lab 
for the frequency range the device can measure i.e. 16,5-12500 Hz. 
Nevertheless it is well known that sound level measurements in the frequency range less than 100 Hz 
are always doubtful. Beyond it a microphone cannot measure a sound level between 16,5 Hz and 12500 
Hz with a sufficient overall accuracy for standard measurements.  
With  good  reason  the  sound  level  generated  by  the  Installation  Noise  Standard  is  given  only  for  the 
frequency range of 100-5000 Hz in the EN ISO 38221. 
We have also to keep in mind that for the measurement of low frequency sound levels less than 100 Hz 
a room with ideal infinite mass is required. 
The best labs for low frequency sound level measurements are old bunkers of the Second World War, 
but also not every one. 
In  Table  5  the  sound  level  values  for  the  particular  frequency  range  of  the  INS    (100-5000  Hz)  have 
been added in the light green lines. 
It  can  be  seen  that  the  dominant  contribution  to  the  Leq  =  50,3  dB  results  mainly  from  the  bad 
measurable  frequency  range  under  100Hz  independently of  a  later  adaptation  of  the  results  to  human 
hearing characteristic by the A-correction. 
Looked  at  in  this  way  the  A-correction  not  only  adapts  the  physically  generated  sound  to  the  human 
audibility. 
It procures also a positive side effect discarding simultaneously the part of the spectrum, which cannot 
be measured correctly. 
In  table  6  revealing  the  corresponding  values  for  the  ISQ-lab  it  is  clear  that  the  dominant  part  of  the 
noise spectrum acts also in the range of 100-5000 Hz. 
Fig. 23 shows the one-third-octave spectra of the external noise sound level for the two labs visualising 
the information the tables 5 and 6 give numerically. 
In any case the main contribution of the external noise happens in the low frequency range less than 200 
Hz whereas the contribution above 5000 Hz is negligible. 

4.12  Measurements with the basic wall, placement 1 (see Fig. 24) 

4.12.1  Basic wall 

The basic wall has been the backbone of all the measurements and different variants measured.  
Following the example of a real existing steel (show) house of Fig. 2 it has the size of  3.75x2.5 m. It 
consists of three single modules each of 1.25x2.5 m in accordance to customer planking dimensions. 
Therefore the measurement arrangement (the placement 1) is very simple like it can be taken out from 
the Fig. 24. Due to its simplicity the basic wall is predestined for the lightening of the most important 
questions like 

- 

- 
- 

What  is  the  suitable  fastening  manner  of  the  clamps  to  the  wall  for  the  whole  course  of  the 
project (EN ISO 3822-1 like or not)?  
The cross-reference measurements gypsum board versus gypsum fibreboard  
The effect of fastening the clamp on a C-profile or aside  

23 
 
 
 
 
 
 
- 

- 
- 
- 
- 

Does  a  large  light  gauge  wall  vibrate  as  whole  entity  or  are  the  single  modules  vibrating 
independently, because the pipe is exciting every module by spot fastening?  
How the vibration energy is really transmitted through the wall and how it can be reduced   
The effect of primary silencers (sound barriers) on the reduction of the fitting noise 
The role of secondary silencers in the attenuation of fitting sound level   
Solutions for the attenuation of the fitting noise by additional layers 

Due to its straight geometry it is the most suitable wall for FEM-simulation, which has to bring light 
into the interpretation of the experimental results and clear some fundamental assumptions. 
This is the reason why the following broad sections deal with measurements and calculations around the 
basic  wall  whereas  the  further  arrangements  are  treated  mainly  from  the  point  of  view  of  the 
experimental results. 
Fig. 25 left shows the basic wall placed in the measurement orifice (see Fig. 14) before the planking has 
been completed. In Fig. 25 right the pipe of material and dimensions in strict accordance to the standard 
EN ISO 3822-1 has been attached.  
How required the pipe has been fixed to the wall with four strong clamps at irregular spacing to avoid 
the formation of low vibration modes of the pipe. 
The  clamps  are  fixed  on  four  steel  plates  of  5  mm  thickness  and  of  dimension  100x100mm  also 
prescribed.  
This required very strong connection is due to the use of a massive stonewall in the standard EN ISO 
3822-1. It should be less compelling in the case of light gauge walls. 
But having taken the decision to follow the guidelines of this standard it was useful to remain as narrow 
as possible to its rules if they don’t contradict the target of the project. 
Fig. 26 left and right show the test wall from the side of the microphone room. 
In Fig. 26 left the fastening of the clamps is performed strictly according to EN ISO 3822-1.  
In this case the thread goes through the wall and is hard connected to the two opposite boards. The pipe 
vibrations displace both wall sides simultaneously. 
See also the middle sub-picture of Fig. 20 for more details.  
In Fig. 26 right the wall facing the microphone room has no more hard connection to the pipe in the 
mounting room. 
The pipe has been only hard fastened to the first wall side as it makes more sense in the case of practice 
of dry lining constructions. 
Supplementary the option that the fastening is accidentally positioned directly on a steel  member has 
been also analysed. 
Fig.  27  left  shows  the  two  alternative  positions  of  the  clamp  from  which  the  left  is  fastened  on  a  C-
profile 
Fig. 27 right reveals the fastening details inside the planking. 
Because the EN ISO 3822-1 prescribes only four clamps the two options are used alternately. 

4.12.2  Suitable fastening for light gauge walls (EN ISO 3822-1 or not) 

We started the measurements in strict agreement with the standard EN ISO 3822-1, where the tree rod 
has to go through the entire wall and be fixed with the steel plates to the two opposite sides of the wall. 
If we really wanted to proceed strictly in accordance to the standard we had had to use also a stonewall. 
Indeed the procedure is finally a contradiction in terms.  
Nevertheless it is an instructive trial concerning the INS performance. 
In this arrangement the GF wall acts like a huge loudspeaker membrane totally controlled by the pipe 
generating a maximal sound level. 
Table  7  shows  the  total  sound  levels  as  they  are  and  A-corrected.  It  is  interesting  that  there  is  no 
difference between the non- and the A-corrected sound level. This means that the entire sound intensity 
acts in the audible area. 
Later some measurements of the sound level in the mounting room have been performed where the pipe 
was detached from the wall. So it should vibrate free.  
The measured sound level was also about 60 dB. 
Therefore the values of the table 7 reflect the total sound energy of the pipe obviously without being 
disturbed by the wall. 

24 
 
 
 
In the next trials the clamping was realised only on the wall pipe side. The clamps were fixed with the 
four steel plates on both sides of the boards, so the connection between pipe and board was complete. 
See also Fig. 20, left sub-picture. 
Table  8  gives  the  equivalent  values  to  table  7  (fastening  according  to  EN  ISO  3822-1)  for  the  new 
fastening. 
The Fig. 28 shows the spectrum of the A-corrected sound level according to the fastening related to EN 
ISO 3822-1 and to one side clamping only. 
The figure doesn’t reveal some extraordinary features. 
Obviously  the  one  side  clamped  wall  transports  the  sound  level  spectrum  to  the  measurement  side 
without distortion but weaker. 
Nevertheless  it  is  the  connection,  which  allows  the  exertion  of  influence  to  the  transport  of  vibration 
energy from the pipe side to the other side of the wall and therefore meets the project intentions. 
Last  but  not  least  it  is  the  usual  manner  of  fastening  water-feeding  systems  in  the  dry  lining 
construction. 

4.12.3  The cross-reference measurements gypsum board versus gypsum fibreboard  

Comparison FQZO/ISQ 

Because ISQ never performed the cross measurements but measured only their material gypsum board 
there are only cross-reference measurements of FQZO gypsum versus gypsum fibreboard which can be 
compared  with  the  corresponding  measurements  of  gypsum  board  in  the  same  experimental 
arrangement by ISQ. 
Fig.  29  reveals  the  continuous  sound  level  spectra  Leq  of  gypsum  board  of  ISQ  and  gypsum  board, 
gypsum fibreboard of FQZO at the one-third-octave centre frequencies. 
At the first glance it can be learned that gypsum board and gypsum fibreboard measured by FQZO have 
a similar sound level and spectrum. 
The corresponding gypsum board spectrum measured by ISQ differs strongly from the two others. 
Because  of  the  rather  high  difference  of  the  external  noise  of  the  two  labs,  all  the  spectra  have  been 
noise cleared. Of course in practice the audible sound level is the contribution of the two sources to the 
total sound. 
The result is given in the next Fig. 30. 
It is obvious that the ISQ sound level spectrum of Fig. 29 consists mainly of external noise. 
The more quantified analysis is given in the tables 8, 9 and 10. 
In the yellow line of the tables the result of the noise cleaning operation on the sound level for both labs 
has been added. 
If we look finally to the sound level audible to human being performing an A-correction operation of 
the noise-cleared spectra of Fig. 30, we obtain Fig. 31.  
The value of the sound level of the gypsum board measurements by ISQ corresponds obviously to “low 
breathing” according to Fig. 11.  
In the following we use the results of FQZO to go forward in the matter keeping in mind the necessity 
to  discuss  the  discrepancies  between  the  two  labs  again  and  consider  the  fact  that  gypsum  board  and 
gypsum fibreboard give surprising comparable results. 
Gypsum board is the standard material for dry lining how it was explained in depth in section 3.3. 
So it was natural to take it as the number one in the consideration. 
The  second  material  with  lower  spreading  but  recommended  for  higher  load  cases  the  gypsum  fibre 
board was the second partner par excellence. 
These both materials cover the most business in dry lining. 
This was the background for the decision to introduce the two competitive materials into the project. 

From  the  point  of  view  of  a  simple  analytical  model,  the  all-round  hinged  isotropic  plate,  the 
eigenfrequencies of the materials can be described by a material specific factor times a factor containing 
the mode number “m”, ”n”, in x- and y-direction and the geometrical dimensions the plate length “a” 
and width “b”. 

               Eh2 4          
mn
             12(1-µ2)         

2  =     f(m,n,a,b)        

                  (9) 

25 
 
 
 
 
 
 
     
      
 
 
The gypsum board is not isotropic having different Young modules in x- and y-direction perpendicular 
and parallel to the casting direction. 
The gypsum fibreboard is isotropic due to the stochastic distribution of the fibres inside. 
The Young-modules, raw densities and more for the two materials are compiled in table 3. 
The material properties are concentrated in the ratio E/ for gypsum fibreboard and in Exx/, Eyy/, or 
3.3 for gypsum fibreboard and 3.2 and 4.1 for gypsum board respectively. 
Obviously these differences are of secondary importance for the real generation of audible sound under 
technical conditions. 
Table 9 shows the cross-measurements gypsum board (3 bar) versus gypsum fibreboard carried out by 
FQZO.  
The sound level “unclamped” is the sound level the pipe produces if it is disconnected from the wall. So 
the  pipe  generates  an  airborne  sound  in  the  mounting  room,  which  passes  through  the  wall  being 
damped by the acoustic mineral wall. 
In  both  cases  GB  and  GF  the  mineral  wall  proportion  is  the  same.  The  slightly  higher  difference 
between Leq and the A-corrected LAeq of GF may be due to a higher low frequency contribution of the 
planking material. 
At the maximum we have a a sound level difference between gypsum board and gypsum fibreboard of 
1,2 dB. So all the sound level results elaborated with gypsum fibreboard are also relevant for the case of 
gypsum board and vice versa. 
To save place the results of the next section have been also introduced to the table 11. 

4.12.4  The effect of fastening the clamp on a C-profile or next to it 

In the daily handicraft it can happen that a clamp is fastened on a C-profile. Therefore it was interesting 
to study this practical case. For saving work only the position of the first clamp nearest to the INS was 
modified to realise two positions, one on the C-profile and a second 12 cm aside of the profile. 
The table 11 in which the measurements for GB as well as for GF for the two positions of the clamp are 
compiled reveals a low effect of the fastening of the clamp on the C-profile contrary to the expectation. 
In the case of GB there is no difference. For GF a difference of 2 dB has been found, which is rather 
low. 
Indeed it is good news because this means that light gauge lining is rather redundant to bad work. 

4.12.5  The sound level measurements with the placement 1 

The  first  measurements  discussed  above  considered  the  relation  between  gypsum  board  and  gypsum 
fibreboard and the fastening techniques. In a certain sense they were necessary supplementary trials to 
start the measurement programme with a well-defined background 

To avoid a too wide diversification only the same number of boards on both wall sides have been used, 
either  single  planking  or  double  planking  on  both  sides.  This  rule  has  been  kept  also  for  the  other 
further arrangements. 
Because the OSB-panels have a thickness of 19 mm they have been used in connection with a double 
planking (12.5mm+10mm) of GF or GB on the opposite side to reach a similar thickness on both sides. 
Last but not least a 100 mm thick polystyrene layer has been use on the OSB-panel side to simulate the 
condition of supplementary thermal insulation of the outer wall.  

In this section the results of the regular measurement programme in the placement 1 with the basic wall 
are discussed. The following programme has been carried out 

- 

- 
- 
- 
- 

Usual  steel  frame  (see  Fig.  5  left  and  also  section  4.5),  single  planking  GB  or  GF,  thickness 
12.5 mm  
Usual steel frame, double planking GB or GF thickness (12.5 +10.0) mm 
Frame with slit C-profiles (see Fig. 5 right), single planking GB or GF, thickness 12.5 mm 
Frame with slit C-profiles, double planking GB or GF, thickness (12.5+10.0) mm 
Usual steel frame, one side double planking GB or GF thickness (12.5+10) mm, other side OSB 
thickness 19 mm 

26 
 
 
 
 
 
 
 
- 

- 

Usual steel frame, one side double planking GB or GF thickness (12.5+10) mm, other side OSB 
thickness 19 mm + polystyrene thickness 100 mm 
Usual steel frame, double planking GB or GF thickness (12.5 +10.0) mm, earth quake version 
(see Fig. 32) 

The most important characteristics of the complex “placement 1” have been compiled in the two tables 
12 and 13. 
In table 12 the results of the airborne measurement have been compiled. In this case the pipe is detached 
from the clamps and vibrates free, generating an airborne sound in the mounting room of round 60 dB. 
This sound is attenuated by the acoustic mineral wool inside the wall. 
Although the results of the airborne sound measurements don’t stay in the centre of attention they fulfil 
an important check function. 
Because  every  wall  variant  must  be  erected  new,  the  sound  insulation  of  the  new  wall  against  the 
surrounding lab envelope must be renewed every time. 
So  the  measurement  of  the  airborne  sound  helps  to  assure  the  repeatability  of  the  experimental 
conditions. 
Because of that the results of the airborne measurements are always given.  
As it can bee seen in the different values of the sound level of the walls with usual steel frame and those 
with slit C-profiles of table 13 a certain transport of vibration energy over the frame takes place. 
After all the difference for single planked walls comes to 5.5 dB and to 3.2 dB for double planked.  
The  most  impressive  result  although  not  being  an  objective  of  the  project  concerns  the  best  result 
reached by the combination of double planking and OSB with usual steel frame. 
This combination is rather better than that of the “specialists” for airborne sound attenuation, the walls 
with split C-profiles. 
Due to a higher stiffness the earthquake version reaches also the same performance like the slit profile 
walls concerning the attenuation of airborne sound. 
Clamping the pipe to the wall all the results become rather worse. 
Nevertheless there are some differences between the results, which are worth to be commented. 
In the second highlighted line the interpretation philosophy of the EN ISO 38221 is applied. This means 
a noise source with a sound level of X dB, here the INS with a calibrated sound noise level of 46,8 dB, 
forcing  the  water  feeding  circuit  to  vibrate  generates  a  sound  level  in  an  adjacent  room  which  is 
weakened by the values of line two in dependence of the nature of the wall used. 
If the source produces a lower sound level than the  INS, for instance 36 dB, the wall W2F-10 (usual 
steel frame, double planking GB or GF) should reach an attenuated sound level of 31,5 dB and the wall 
W4F-10 (slit profiles, double planking GB or GF) 30,7 dB. 

Obviously the transport of vibration energy generated by a water feeding system attached to one wall 
side via the C-profiles seems to be rather weak. 
Because the transport of vibration energy in the case of the frame with slit C-profiles can only run over 
the upper and bottom U-profile, it should be the main transport mechanism for all the walls and frames. 
So the sound level generated by the double-planked basic wall with continuous C-profiles differs only 
by about 0,8 dB from the double-planked wall with split C-profiles within the range of no distinction by 
human.  
The  best  wall  for  airborne  sound  attenuation  (GF/OSB)  doesn’t  keep  its  first  place  when  the  pipe  is 
clamped. The pipe is clamped to the double-planked gypsum fibreboard. 
The addition of 100 mm rigid foam deteriorates the performance further even it is small. The rigid foam 
is sound hard and has the same effect also in commercial practice. 
Its use is primarily due to its excellent thermal insulation properties. 
The earthquake variant (Turkish norm, see Fig, 32) is as so good as the single planked wall with split C-
profiles both in the airborne attenuation and in the clamped case. 

4.12.6  First conclusions 

1. 

2. 

Walls bearing the water feeding system should always be double planked 

The vibration transport runs obviously mainly over the top and bottom U-profile to which all 
the C-profiles of the wall are attached. The transport over the C-profiles is rather weak. 

27 
 
 
 
 
 
3. 

4. 

5. 

6. 

The C-profiles play a greater role in the case of airborne sound transport than in the case of wall 
vibrations introduced by a spot fastened vibration source on the wall 

OSB panels  are excellent airborne sound barriers also using usual steel frames. In connection 
with a double planking with GB or GF their performance is higher than that of the walls with 
slit C-profiles, double planked   

The earthquake version (double planked, usual steel frame) reaches the performance of a single 
planked wall with slit C-profiles in the airborne sound attenuation as well as in attenuation of 
fitting noise 

Nevertheless the performance of all the versions is unsatisfactory, so that a deeper analysis of 
the vibration mechanism of the walls must be undertaken. In addition a significant improvement 
of the performances of the best wall versions must be reached. 

4.13  The physics of light gauge vibrations by point sources,  

FEM simulation of the wall vibration 

In this broad section the performed FEM calculations are reported. The target of this work was to find 
out 

- 

- 

- 
- 
- 
- 

Does  the  wall  vibrate  as  assembly  i.e.  as  a  large  panel  of  size  3.75x2.50  m,  single  or  double 
planked or as single modules? Because the introduction of the pipe vibration into the wall takes 
place spot like into the single modules (see Fig. 33) it should be expected that this feature will 
dominate. 
The answer has an essential importance because it settles the possibility of self-annihilation of 
vibration between the opposite wall sides. 
How important are the C-profiles in the steel frame concerning the transport of vibration energy 
through the wall? 
What can the FEM say to the improvement of the situation reported in the last section? 
What are the eigenmodes of the pipe, panel and members?  
What modes can be shifted or suppressed by additional measures or (pipe) design 
Are there (sligthly) different modes between the opposite panels due to the connection by the 
steel members, so that self-annihilation of vibrational energy can be induced connecting the two 
opposite panels?   

The usefulness of FEM for the understanding of almost all technical problems is well established. 
Nevertheless the working out of physically real results requires a very careful self-critical processing. 
The physical and technical problems are governed by differential equations that are the finite limit of 
the transition of a finite difference quotient to zero.  
The FEM as the name already says doesn’t execute this transition. In relation to vibrational analysis this 
means that in the worst case the eigenfrequencies are limited by the mesh size and not by the physical 
properties of the object. 
The usual pragmatic way to establish the physical plausibility of the results is to reduce the element size 
step by step until then the vibrational spectrum becomes constant or nearly constant.  
This results also in a considerable increasing of the calculation time and destabilisation of the numerical 
process because some limit conditions of the explicit time routine become worse with the reduction of 
the  mesh  size.  It  is  not  compulsory  that  the  convergence  becomes  obvious  in  the  feasible  range  of 
downscaling. 
In some simple cases the comparison of the FEM calculation with an analytical solution is possible and 
more convincing.  
The  fundamental  disadvantage  of  the  analytical  solution  is  related  to  the  very  small  number  of 
elemental boundary conditions, which allow to carry out an analytical solution to a full end. 
Therefore the FEM method is less suitable to work out numeric quantitative results near to experimental 
dates, especially if the extension of the object to be discretized is large, like in our case 

28 
 
 
 
 
 
 
 
 
But it is a very powerful tool to find out the correct physical trends, to reject or verify assumptions, to 
make experimental work effective, to classify design rules and more.  

4.13.1  The formulation of the problem 

Before we discuss the different questions to be answered by the FEM, it is of essential importance to 
describe the vibrational system we wanted to analyse. 
As already described, single modules consist of two boards screwed on a steel frame, itself consisting of 
three vertical C-profiles screwed to two horizontal U-Profiles (see Fig. 5). 
The U-profiles are screwed into the floor and ceiling. In real domestic applications for the non-bearing 
walls there is a foam strip between the U-Profiles and the floor concrete to reduce sound transmission 
(Fig. 34a). 
In reality the question how effective the action of the foam strip on the sound transmission is, should be 
difficult  to  answer  because  the  characteristic  of  foam  is  difficult  to  manage.  Up  to  a  certain  load  the 
foam shows an inelastic behaviour being capable to damp vibrations successfully. 
Over that limit the foam becomes incompressible like rubber and the benefit of its introduction into the 
wall becomes rather indifferent. 
Always the consideration of foam characteristics in modelling is connected with a lot of imponderables 
and is discarded from the modelling of wall vibrations in this work.  
The target of this work is to find out asymmetries in wall vibrations and to work out measures to reduce 
vibration energy by self-annihilation interaction between the boards. Therefore more elemental but clear 
conditions are more suitable for the difficult undertaking. 
If the foam is pulled out of consideration we have only hard fastening conditions between the wall and 
the surrounding (see Fig. 34b). 
Therefore in the total wall of Fig. 3 consisting of three modules the U-profiles (dark blue) are hard spot-
connected to the floor and ceiling. The first and the last C-profiles are also hard connected (light blue). 
This is always the case if the wall ends at the position of a sidewall. If not the last C-profile (see 
Fig. 3, red ellipse) has no constraints outside the ends fastening to the U-profiles. 
For  the  simulation,  first  and  last  C-profile  (light  blue)  have  the  same  hard  spot-like  fastening  to  the 
surrounding as the U-profiles. 
It is also the practical case of bearing walls that must have a hard connection to the floor and ceiling to 
bear the loads of the next upper floor. 
The hard fastened U- and C-profiles cannot transmit vibrations from one board to the opposite one like 
the free C-profiles. They function mainly as a hinge with a pull back torque (see Fig. 35a).   
All other C-profiles (green), which are only connected at their ends with the U-profiles and to which the 
panels are screwed, can follow the board vibrations by bending and twisting (see Fig. 35b). These are 
the transmission agents for the pipe vibration.  
The unique active element responsible for the sound finally reaching the microphone in the test room is 
the Installation Noise Standard of Fig. 15. Its vibrational spectrum is given in Fig. 16. 
Because the INS is rigidly attached to the pipe, the pipe rigidly fastened to the first board, INS pipe and 
first board form the exciting system. 
Indeed  the  transmission  of  vibration  from  the  pipe  to  the  human  ear  is  a  connection  and  filtering 
problem as it can be seen in Fig. 34 because most of the elements, profiles and board facing the human 
ear are passive elements, which are “externally” excited via their connections to the first board. 
By means of the attachment to the first panel by a mechanical connection the steel members transmit 
the vibration to the opposite connection to the second panel in which the vibration energy is introduced. 
The connections of the C-profiles to both panels determine the kind of possible vibration modes of the 
steel members and therefore what energy amount is transmitted through the wall. 
An external source exciting a passive system acts markedly on it only if its frequency spectrum fits the 
eigenfrequencies of the system. This property of every subsystem is condensed in the so-called response 
function in the time-space (or filter function in the frequency space) of the system or subsystem.  
Every  subsystem  has  an  own  response  function  and  filters  the  incoming  spectrum  by  its  response 
characteristic before it is transmitted to the next station. 

29 
 
 
 
 
 
 
4.13.2  Boundary conditions 

In  a  simplified  sense  the  way  of  FEM-calculation  using  commercial  software  can  be  reduced  to  the 
meshing of the object and the formulation of the boundary conditions of the problem. 
The  formulation  of  the  boundary  conditions  is  the  backbone  of  the  transition  of  a  certainly  diligent 
business of meshing to a physical mapping of the reality. 
This  is  the  reason  why  the  discussion  of  the  boundary  conditions  used  takes  a  wide  room  in  the 
discussion and specially their deviation from the real physical conditions. 
As it has been stressed at the beginning of 4.13 the FEM starts already with a basic deviation between 
numeric simulation and lab arrangements shown in Fig. 35 and 36. 
The connection between light gauge wall and surrounding in the FEM and the lab is quite different. 
In Fig. 35(b) the contact between the light gauge wall and the surrounding is complete but because the 
surrounding  is  not  part  of  the  FEM-discretization  no  interaction  and  vibration  transfer  to  the  outside 
takes place. 
Nevertheless in the FEM calculation the hard fastened profiles cannot contribute to the transport of the 
vibration energy to the opposite panel. 
The  experimental  arrangement  is  totally  uncoupled  to  the  surrounding  wall  to  have  an  unadulterated 
wall  vibration  contribution  to  the  sound  level.  Therefore  in  the  lab  measurement  all  the  members  are 
free floating according to Fig. 35a and transmit vibration.  
In both cases the eigenmode values would be comparable because they don’t depend on the excitation 
manner but from the geometrical dimensions and physical properties of the materials used.  
The  next  set  of  boundary  conditions  is  related  to  the  connection  between  the  board  and  the  steel 
members.   
There are several levels of complexity in regard of module vibration because of the different abstraction 
of  the  connections  between  planking  and  members.  Every  level  of  complexity  helps  to  distinguish 
between different qualities of real fastening.  

- 

- 

Load case 1: The simplest one is the consideration of plate vibrations of a plate fully fastened 
by rigid boundary conditions on the steel frame, so that the wall vibrates in solidarity with the 
steel frame. (See Fig. 37:  black tape: full fastening) 

Load case 2: The connection between the wall and the chassis is realised by contact (tie), and 
the contact area is lower than in the case 1.  The distance in which these "areas of union" are 
located  is  approximately  200  mm  in  accordance  with  the  planking  fastening  on  members  by 
screws in the physical case. (See Fig. 38; red tape: tie area) 
The load case 2 meets real conditions better than others. Physically the panels are fastened to 
the profiles by screwing. The screw if the business has been well done presses the board to the 
profile and generates a contact area (see Fig. 39). 
Mathematical  processing  of  contact  problems  must  be  formulated  in  relation  to  Fig.  40.  The 
physical screw must be removed so that the contact remains without internal singularity. 
The tie must not be rigid (infinite) because an infinite tie results in a singularity of the problem 
at the edges of the contact area and therefore the numeric calculation fails. 
So an uncertainty is generated in regard of the value of the tie which remains finally arbitrary. 

In  the  load  case  1,  the  board  can  perform  only  vibrations  in  connection  with  vibrations  of  the  steel 
members (See Fig. 41a). Especially in the corners the resultant higher rigidity of the steel connection 
annihilates mostly the displacement of the board in the normal direction to the plane as well as that of 
the steel construction itself. 
In the load case 2, the fastening between board and members continues to be tight but becomes more 
spot-like.  It  can  be  assumed  that  the  elemental  vibration  modes  of  the  load  case  1  especially  at  low 
frequencies are also modes of the load case 2. 
The number of degrees of freedom of the board increases considerably resulting in a higher number of 
vibration  modes  at  higher  frequency  of  the  board  (See  Fig.  41b)  because  new  vibration  modes  are 
possible.  
If we give up the condition of finite contact area we come to the opposite limit, the point connection 
shown in Fig. 42. 

30 
 
 
 
 
  
The node of the member facing the node of the board (Fig. 42, blue A) and that node (Fig. 42, red A) 
are molten to one new node. 
Between this new node and the equivalent board node on the other side of the board (Fig. 42, red B) a 
connection property with defined stiffness must be formulated. 
There  are  two  different  models  for  the  connection  property  at  our  disposal,  the  rod  or  beam  model 
(bending, no elongation) and the spring model (elongation, no bending).  

In reality a wire spring has at least three translation and bending degrees of freedom. 

-  

- 

- 

Load  case  3:  The  planking  is  tightened  to  the  frame  with  screws  of  8  mm  of  diameter;  the 
numerical  model  used  to  model  the  screws  consists  of  a  beam  element  (See  Fig.  43a).  If  the 
bending moment of the screw is weaker than that of the profile the board will bend the screw. 
Nevertheless the beam element doesn’t mean that the planking cannot perform other vibration 
modes.  Especially  in  the  case  of  non-bearing  walls  with  a  thickness  of  0.6  mm  the  screw 
connection  should  be  so  stiff  in  comparison  to  the  bending  moment  of  the  C-profile  that  the 
load case 1 should be more plausible. Generally we will find more complex displacements like 
in Fig. 43b where the profile and the screw are bent in relation to their bending resistance. 

Load case 4: This case is  similar to the previous one, but the beam  element is replaced by a 
spring element that does not support bending but only tension and compression with a spring 
constant  of  10  KN  /  m  (See  Fig.  44).  So  the  board  has  a  zero  deflection  at  the  screw  point 
similar  to  the  rigid  tied  plate.  Also  here  the  possibility  of  mode  complex  displacements  is 
possible.  

Load case 5: case exactly like the load case 4, but the model is much larger (3 times larger than 
the base of the case 4, which corresponds to the  structural module in Fig. 3). The connection 
between planking and steel chassis is also ensured by spring elements of 10 kN/m. 

What is the essence of this set of conditions? 

The first load cases 1 and 2 force coherent vibrations of steel member and planking. In any case they 
are plausible for non-bearing walls, where the thickness of the steel members is only round 0,6 mm and 
less. The reduction of the fastening area in the load case 2 allows more vibrational modes of the board 
in the direction of screw-like conditions. 

The further weakening of this rigid condition introducing the degrees of freedom of the screws makes a 
certain decoupling of the wall vibrations from the steel member possible. Bearing wall steel members 
have  a  material  thickness  of  1.5  mm,  so  their  influence  on  the  vibration  of  the  planking  may  be 
overrated by full rigid boundary conditions.  
In a certain sense from the point of view of net effect the introduction of softer boundary conditions by 
screw  elements  in  stiffer  bearing  members  may  be  comparable  to  that  of  rigid  conditions  for  thinner 
steel profiles with reduced fastening area. 
Finally  the  screw  should  be  simply  the  limit  of  the reduction  of  the  fastening  area  to  nearly  zero  but 
without reducing the grid size in such a manner. 
Nevertheless  it  must  be  kept  in  mind,  that  the  connections  between  the  different  elements  of  the 
compound are never so tight that all of them act coherently. In particular the connection of screw and 
gypsum board is non-elastic and therefore less favourable for common excitation. 
In the course of different studies the load case 2 has been established as the most efficient model for 
light  gauge  elements  simulation  in  the  light  of  convergence  with  the  downscaling  of  the  mesh  size. 
Although it is not an absolute criterion for the validity of the results it suggests the closest proximity to 
an analytical solution of the problem.   
Load case 2 contains the characteristic of load case 1 (see Fig. 41a) for low eigenfrequencies as well as 
more degrees of freedom (see Fig. 41b). 
In  the  case  of  thin  members  and  low  frequencies  it  can  be  assumed,  that  the  situation  of  Fig.  41a  is 
predominant. The project considers also bearing walls with profile thickness of 1.5 mm so that different 
features for different walls can appear. 

31 
 
 
 
 
 
 
  
FEM  starts  with  the  generation  of  the  grid  image  of  the  physical  reality.  For  high  effectiveness  a 
meshing philosophy must be developed to find out a common grid size for all the elements so that the 
downgrading of the mesh size can be performed on one push. 
Because  the  different  materials  have  different  vibrational  eigenfrequencies  and  therefore  different 
wavelengths  it  is  difficult  to  find  a  common  meshing  with  which  the  vibrational  properties  of  all 
elements are taken into account. 
At  least  five  nodes  are  necessary  to  reproduce  a  wave,  therefore  mesh  size  limits  the  number  of 
eigenfrequencies the numeric system generates.   
Next  to  the  boundary  conditions  the  contact  between  the  different  elements  of  the  module  coming 
together must be carefully defined. 
In the worst case a beam can penetrate into the wall or vice versa when the two elements don’t vibrate 
coherent and there is no well defined contact between them. 

A wall module finally consists of a set of connections consisting in  

- 
- 
- 

Connection U-beam to C-beam 
Connection U-beam to the wall 
Connection C-beam to the wall 

At  every  corner  of  the  modules  all  elements  of  the  assembly  come  together  to  a  very  complex 
connection (see Fig. 45) 

There are different complex interactions 

- 
- 
- 

- 
- 

Interaction wall 1, wall 2 to U-beam 
Interaction wall 1, wall 2 to C-beam 
Interaction  wall  1,  wall  2  to  U-beam  to  C-beam  in  the  corners  of  the  module  and  cross 
connection in the middle of the U-beam 
Interaction U-beam to C-beam 
Interaction wall 1 to wall 2 mediated by the chassis  

After all the interactions have been defined the next step consists in defining the kind and strength of 
the connections between the different components.  
After a long work of model analysis the tie connection has been found as the most adequate to describe 
the reality of screw connections because a screw connection always generates a larger contact surface 
between the parts it joints. On the other hand a tie introduces a new parameter, the strength of itself. 
In addition the area for the tie must be defined, generally equal to a mesh unit (see Fig. 46a) and finally 
the tie created (Fig. 46b). 
The definition of a tie on a finite area has a large disadvantage at the moment at which the downscaling 
of the mesh size is processed. Having defined the tie area based on mesh size it becomes also smaller 
the smaller the mesh size becomes. 
So the reproduction of the physical reality changes with the mesh size if the tie area is not adapted to 
the inaugural size, which implies that the downscaling of the mesh size runs with n = 2,3,4,5 resulting 
in computer time increasing of 22,32,42,52 and more. 
The  alternative  consists  in  defining  a  node  tie  of  plausible  strength.  This  is  always  yet  a  better 
alternative  than  to  define  a  bending  or  spring  model  for  the  node  connection  between  wall  and  steel 
profiles. 
So in the following only the node tie model will be used for the further work. 
Fig.  47  shows  the  complete  assembly  of  one  single  module  1250x2500  mm2  and  all  the  tie  nodes 
between wall and chassis. 
In the tie model some articulation between U- and C-profile can be defined. This is important for the 
reproduction of the real case because board and beams are only connected by a self-cutting screw and 
can wrench to another. 
Last but not least the boundary conditions (fastening to the surrounding) of the webs of the members 
defining the outer dimension of the module have been defined according to Fig. 48  

32 
 
 
 
 
 
 
Currently the assembly has boundary nodes “red stars” in Fig. 48 of condition type “fully restrained” 
applied to the two U-beams (in front and at the back of the module) and the C- beams exterior surfaces 
(left and right of the module). 

4.13.3  FEM-Calculation of the single module 

The module is subjected to the gravitation force (9.81 ms-2) and to a point force of 1000 N nearly in the 
centre of gravity of the board. 
Fig.  49  shows  the  first  eigenfrequency  of  the  wall  module  according  to  the  boundary  conditions 
presented in Fig 48. In this example, the gypsum board (2500x1250x12.5 mm) and non-bearing profiles 
(thickness 0.6 mm) were used for the calculation. The red stars are the points of rigid fastening of the 
web of the U- and C-beams.  
The first vibration mode has the same shape as an all-round fastened single plate without intermediate 
beam.  The  intermediate  beam  doesn’t  seem  to  influence  the  vibrational  behaviour  of  the  board.  It 
follows  totally  the  displacement  of  the  planking  according  to  Fig.49b.  It  works  like  a  hinge  without 
damping because the damping constant of steel is very small. 
We close this case with the Fig. 50 for the ninth eigenfrequency at 27.315 Hz. 
As most important fact it results that spot-like rigid fastening conditions of the side webs of the module 
don’t prevent the transport of the vibration of the board subjected to the action of a locally limited force 
(pipe fastening) to the opposite one independently of its position on the board. 
From the point of view of numerics the web can move freely between the rigid fastening conditions. In 
practice between the U-webs and ceiling/floor a foam-interlayer is placed to prevent the transmission of 
the ceiling vibrations to the walls, so that in the dimension of vibration amplitude the webs are damped 
by the foam but remain nearly free.  

4.13.4  FEM-Calculation of the total wall 

In  the  last  section  the  vibrational  response  of  a  wall  module  of  1250x2500  mm  has  been  calculated 
because it is the grid size for larger walls as multiple of the single wall module. 
In addition the fastening of the pipe by means of clamps according to EN ISO 3822-1 acts always on 
the  panel  of  the  single  module.  So  the  introduction  of  vibrational  energy  takes  place  into  the  single 
modules. 
On  the  other hand  the  experimental  measurements  make  clear,  that  sound  transmission  from  the  wall 
side where the pipe is clamped (pipe side, WallP) is transmitted by every elastic connection to the other 
side  of  the  wall  facing  the  measurement  room  (microphone  room,  WallM).  Therefore  the  assumption 
the  wall  should  vibrate  as  entirety  must  be  checked,  because  the  possibilities  of  influence  the  sound 
transmission become different from those for the single wall module. 
So the modelling of three joined single wall modules, in total 2500x3750mm fully restrained by single 
joints between C and U profiles to the frame has been performed. 
In the next figure (Fig. 51), the assembly of the three panels on each side linked together with the steel 
profiles to one whole and the contact areas between C-, U-beams and panels is summarized. 
The  mesh  size  of  25  mm  has  been  kept  as  a  good  compromise  in  relation  to  the  convergence  of  the 
FEM-results toward analytical solutions. 
Fig. 52 shows the displacement of the board for the first, the Fig. 53 that of the fifth mode. Obviously 
the  steel  members  follow  the  displacement  of  the  board  without  influencing  the  displacement 
appearance.  For  more  clearness  the  displacements  have  been  rather  exaggerated.  Indeed  the  real 
displacement is less than 1 µm. Within this very small dimension, it is understandable that the members 
follow the board displacement. 
The  detailed  figure  54  for  the  fifth  mode  shows  more  precisely  the  interplay  of  members  and 
plasterboard. 
At  the  tie  location  (white  arrows)  the  stiffness  of  the  C-geometry  imposes  the  preservation  of  the 
original geometry but without influencing the displacement of the board to such extent, that some low 
frequency single modes are suppressed in benefit of higher frequency modes. 
It is obvious that this influence concerns only the profiles at the beginning and the end of the wall (see 
Fig 54.a) because there the plasterboard has a free edge. 
In the net balance a single planked wall of gypsum/gypsum fibreboard has a weight of 178/234 kg in 
relation to the total weight of the steel members of 40 kg. 

33 
 
 
 
 
The  geometrical  stiffness  of  the  gypsum/gypsum  fibreboard  to  that  of  the  steel  members  where  the 
thickness has an influence on the third power is as 0,007/0,009 for non-bearing walls and 0,10/0.14 for 
bearing walls with a thickness of 1,5 mm. 

4.13.5  Measurement of wall vibrations, clarification of the kind of light gauge vibration 

Measurements of the wall vibrations were not planned in the project. 

They became mandatory due to manifold experimental results 

- 

- 

The results of sound level measurements seemed to indicate that the wall vibrates as entirety, 
making efforts of self-annihilation of wall vibration by coupling opposite panels illusory. 
The FEM calculation of single module and total wall vibration doesn’t produce a self-consistent 
decision what is the real case in practice. It elaborates the mode frequencies and amplitudes for 
all the cases wanted but not more. 
The  first  results  of  ISQ  showed  strong  differences  to  the  measured  spectra  of  FQZO  in  the 
amplitude as well as in the profile. The sound levels were more or less negligible. 
Obviously  there  were  not  so  clear  differences  between  both  lab  constructions  able  to  explain 
such gap. 

So the direct measurements of vibrations seemed to be a way to find the bugs. 
The  device  used  was  a  standard  vibration  gauge  meter  Vibrotest  60  from  Brüel  &  Kjær  Vibro.  The 
sensor was the vibration acceleration sensor AS-065. 
The  device  delivers  also  calculated  and  internally  calibrated  velocity  and  displacement  spectra  by 
integrating the acceleration spectrum. 
Following  the  vibration  measurements  were  extended  to  all  elements  of  the  vibrational  system 
becoming a helpful completion of the sound level measurements.  
Fig. 55 and 56 show details of the measurement procedure on the pipe and on the wall. 
Here the measurements are carried out on the OSB planking. 
All the measurements have been performed in the three co-ordinates according to Fig. 57. 
In total about 1000 vibration measurements have been performed in the course of the project. 
Fig. 58 shows for example the acceleration spectrum measured on the clamp number 2 and the response 
acceleration  spectrum  of  the  wall.  So  it  can  be  established  that  the  wall  is  able  to  activate  its 
eigenmodes also if the excitation frequency differs from their eigenfrequency. 
In this section the vibration measurements are used to find out which vibration model works really in 
practice, so the background of the vibration measurements is kept short. 
Table  14  and  table  15  show  the  results  of  the  calculation  of  vibration  modes  compared  with  the 
experimentally measured values. A mode matching between calculated and measured values less than 1 
Hz was set full green, a matching between 1 and 2 Hz light green. 
The mechanical vibrations were measured on both sides of the module and wall. The designation WallP 
means that the values belong to the module or wall side on which the pipe was attached. The WallM 
name had been taken for the module or wall side facing the microphone i.e. the measurement room. 
In  the  light  of  this  expertise  it  becomes  clear  that  the  highest  degree  of  conformity  is  reached  by  the 
case of total wall vibration. 
This means that there are no possibilities to degrade the transportation energy connecting mechanically 
the opposite boards and other ways must be further looked for. 

4.13.6  Vibration measurement of profiles.  
Clarification how the fitting vibration reaches the opposite wall in the measurement room 

This  section  contains  perhaps  the  most  surprising  and  unexpected  result  of  the  project  lightening  the 
kind of vibration transport from the wall where it is generated to the opposite wall. 
The  sound  level  measurement  results  of  the  first  measurement  campaign  suggested  already  that  the 
transport of vibration energy over the C-profiles i.e. from face to face seemed to be weak. 
So  the  contribution  of  the  members  to  the  transport  of  the  vibration  energy  from  the  wall  where  the 
excitations is initiated to that generating the sound in the  measurement room  has been  measured (see 
Fig. 59 and Fig. 60) on single C-profiles and U-profiles of an opened wall structure. 

34 
 
 
 
 
 
 
 
In the case of split C-profiles the transport via C-profiles doesn’t work. 
In table 16 the transported vibrational energy has been put in relation to that  of the unexpected  main 
energy transport by the U-profile web, which is set to 1. 
The transport of the vibration energy from wall to wall runs across the profile webs, whereas the sound 
level of the flanges is numerically the secondary result. 
It must be kept in mind, that the measured amplitude of the free vibrating flanges without constraining 
their attachment to the boards is too high. 
Indeed the energy transport runs over the webs, so it is the more objective value to consider. 
Because the wall is not hard fastened to the lab envelope according to the rules of the EN-ISO-3822-1 
the transport of the vibrational energy over the upper U-profile web is unhindered and rather high.  
Due to the wall weight the bottom U-profile has a tighter contact to the also elastic but now compressed 
subsoil, so that the transport of vibrational energy is strongly reduced.  
Strictly speaking it is negligible. 
It is obvious that in the real construction case the  transport of sound energy over the upper U-profile 
web must be smaller also without supplementary measures, due to its hard fastening to the ceiling. 
The transport of sound energy via C-profiles in comparison to that transported by the upper U-profile 
under  the  conditions  of  the  EN-ISO-3822-1  observed  in  this  project  amounts  only  to  6.6  %  per  C-
member. 
Therefore it seems now to be clear why wall modules with split C-members don’t meet the expectation 
developed on the airborne performance. 
In  the  case  of  airborne  sound  a  uniform  incoherent  force  field  acts  on  the  whole  panel  coming  from 
every source producing noise inclusive its reflection from every wall (see Fig. 61). 
So  the  wall  can  only  move  as  a  whole  away  from  the  field,  so  all  the  profiles  should  be  evenly 
compressed.  
The vibration energy is transmitted to the opposite wall by longitudinal waves of the profiles. 
In the case of fitting noise in a pipe due to its spot clamping to the board only few point forces act on 
the board resulting in a classical waving of the panels. 
The vibrational energy is transmitted to the opposite board by bending i.e. transversal vibrations of the 
members, mainly the upper U-profile acting as transmission hinge. 
Obviously  due  to  the  appearance  of  modes  in  both  directions  of  the  board  area,  the  torsion  of  the  C-
members hinders the propagation of the vibration by themselves, so that the transmission of vibrational 
energy via U-Profiles becomes dominant.  

Solutions to reduce the transport of sound by acoustic design of U-profiles has been already reported in 
the “Dokumentation 560”3, page 23-24, a compilation of numerous activities around house construction 
in steel by the “Stahl-Informations-Zentrum, Düsseldorf. 

Therefore a supplementary own design of acoustic improved U-profiles has not been followed. 

4.13.7  First Conclusions 

1. 

2. 

3. 

 A light gauge wall consisting of several single modules on which a water-feeding pipe is spot 
fastened on one side vibrates as total wall. Its vibration spectrum is determined by the total size 
of  the  wall  and  not  by  the  size  of  the  single  planks  although  the  pipe  is  spot  fastened  on  the 
single modules. 

 Because of the small thickness of the steel members of 0,6 mm for non-bearing walls and 1,5 
mm for bearing walls the stiffness of the steel frame against bending is rather smaller than that 
of  the  planking.  So  the  vibration  spectrum  of  the  wall  and  therefore  the  sound  level  is 
determined dominantly by the dynamic properties of the boards. 

The stiffness of the gypsum/gypsum fibreboard to that of the steel members where the thickness 
has an influence on the third power is as 0,007/0,009 for non-bearing walls and 0,10/0.14 for 
bearing walls with a thickness of 1,5 mm. 

3 Dokumentation 560, Häuser in Stahl-Leichtbauweise, Stahl-Informations-Zentrum Düsseldorf, S. 23-24  

35 
 
 
 
 
 
 
                                                 
 
4. 

5. 

6. 

7. 

 The vibration energy of the wall side where the pipe is attached is transported to the   opposite 
wall  side  mainly  via  the  upper  U-profile  of  the  steel  frame  and  not  face-to-face  over  the  C-
profiles. The U-profile works like a hinge. 

So the ratio of the energy transported by the U-profile to the C-profile relates like 1:0,06 

 Due  to  this  peculiar  feature  light gauge  walls  with  slit  C-profiles  that  have  a well-established 
better  performance  concerning  the  attenuation  of  airborne  sound  don’t  reach  a  real  better 
performance in the case of fitting noise produced by a feeding pipe.  

Because  the  transmission  of  the  vibration  energy  runs  over  the  upper  U-profile  working  as  a 
transmission  hinge  and  not  face  to  face  a  self-annihilation  of  the  vibration  energy  connecting 
the two opposite faces of the wall by a damping connection should not be successful 

4.14  Measurements with the basic wall and secondary wall placement 2 (see Fig. 62) 

In this section the results of the regular measurement programme with the basic wall in the placement 2 
(see Fig. 62) are discussed. 
In the placement 2 a secondary wall has been introduced reflecting tighter the conditions of domestic 
housings where the basic area is divided in different rooms by additional walls. 

The following programme has been carried out 

    1.  Usual  steel  frame  (see  Fig.  5  left  and  also  section  4.5),  single  planking  GB  or  GF,  thickness 

12.5 mm  

    2.  Usual steel frame, double planking thickness GB or GF (12.5 +10.0) mm 
    3. 
    4. 
    5.  Usual  steel  frame,  one  side  double  planking  GB  or  GF  thickness  (12.5+10.0)  mm,  other  side 

Frame with slit C-profiles (see Fig. 5 right), single planking GB or GF, thickness 12.5 mm 
Frame with slit C-profiles, double planking GB or GF, thickness (12.5+10.0) mm 

OSB thickness 19 mm 

    6.  Usual steel frame, double planking thickness GB or GF (12.5 +10.0) mm, earth quake version 

(see Fig. 32) 

The question how the walls should be connected together can be answered in different manner:  
In the project three different possibilities to join perpendicular walls have been defined, which cover a 
wide range of practical cases: 

7.  Connection  of  the  two  perpendicular  walls  on  a  C-profile  of  the  basic  wall  “hard”, 

(see Fig. 63 A) 

8.  Connection of the two perpendicular walls on a C-profile of the  basic wall “elastic” using an 
elastic interlayer of acoustic foam (compressed foam) between the walls with a density of 120 
kg/m3 (see Fig. 63 C) 

9.  Connection  of  the  two  perpendicular  walls  on  a  position  between  the  members  of  the  steel 

frame (see Fig. 63 D) 

The fourth sub-picture (Fig. 63 A’) doesn’t show a fourth joining version. For better effectiveness in the 
case  of  the  main  wall  constructed  with  split  C-profiles  the  secondary  wall  has  only  the  usual  steel 
frame. 
Because  the  steel  frame  is  a  redundant  orientation  in  the  construction  site  a  concept  where  the 
perpendicular walls are attached to the C-profiles (see Fig. 63 A) is often encountered.  
The connection on the C-profile can be realised “hard” (Fig. 63 A) i.e. without elastic layer between the 
junctions. This version at any rate secures a higher stiffness of the whole construction. 
Because it has been established that the vibration energy runs manly over the top U-profile a connection 
of the two walls on a C-profile of the main wall should not be markedly worse than another. 
Nevertheless  it  is  worth  studying  the  same  connection  with  an  elastic  interlayer  (see  Fig.  63  C)  to 
prevent unexpected things which are not so clearly determined in the dry lining construction. 

36 
 
 
 
 
 
 
 
 
 
 
 
 
The  third  connection between  the  members  of  the steel  frame (see Fig. 63 D) as  expected, should be 
comparable to the second one because the unarmed board acts like an elastic body. 

4.14.1  Results related to measurement placement 2  

This  section  contains  the  most  unsatisfactory  part  of  the  experimental  business,  because  every  single 
result was weaker than that of the former placement as it can be seen in the tables 17 to 22. 
Only the double-planked wall with split C-profile showed an average improvement of –4,3 dB. 
The basic expectation was, that a secondary wall fastened perpendicularly to the main wall hinders the 
vibration of the primary wall as ensemble vibration. 
Increasing the effective mass of the primary wall by an inertia mass should reduce the total sound level 
because the same driving force must move a mass being 75% greater than the initial one. 
Fig. 64 and 65 show two examples of the placement 2 
In  Fig.  64  the  secondary  walls  have  been  clamped  to  the  central  C-profile.  The  supplementary  wall 
stays on a wood plank. 
In  the  wall  connection  D  the  secondary  wall  has  been  screwed  correctly  to  the  panel  outside    the  C-
profile as Fig. 65 shows. 
In retrospect because the very later vibration measurements revealed a dominant transport over the top 
U-profile the connection to a C-profile or to the unarmed board should never cause a surprise. 
To turn the argument on its head, it means the secondary wall could not be put in vibration connecting it 
to a C-profile. Nor it would hinder the move of the basic wall. 
The  too  late  explanation  should  consider  the  fact  that  introducing  a  secondary  wall  into  the  small 
measurement  room  a  reverberation  surface  4/3  larger  than  the  total  area  of  the  basic  wall  has  been 
supplementary introduced heavy disturbing the basic geometry of the measurement room. 
It  had  been  easy  to prove this  idea  disconnecting  the  secondary  wall  from  the  first  and  letting  it  stay 
free. Unfortunately nobody came up with it. 
Assuming this idea should be correct no strong decrease of the sound level should be expected from this 
arrangement. 

4.14.2  First conclusions 

1. 

2. 

3. 

4. 

A secondary passive wall linked perpendicularly to it should not influence the sound level of a 
basic main wall on which the pipe feeding system is fastened. 

Because  the  main  wall  emits  its  sound  into  the  measurement  room  as  in  the  case  of  the 
placement 1, the results should be comparable to those of the placement 1 if the secondary wall 
doesn’t have any influence. 
This is a result of the transport of the vibration energy mainly over the top U-profile instead of 
face to face. 

The  results  have  to  be  better  if  the  secondary  wall  disturbs  the  vibration  characteristic  of  the 
basic wall however it happens. 

Because the results are generally worse we must conclude that the positioning of the secondary 
wall in the measurement room changes the acoustic conditions of the room so drastically that an 
understandable measurement of the arrangement cannot be performed 

4.15  Measurements with the basic wall and secondary wall placement 3 (see Fig. 66) 

The third and last placement 3 is exactly the opposite of the placement 2. Here the secondary wall bears 
the vibrating system and can put the basic wall in vibration by means of one of the connections of Fig. 
63 already used in the measurement campaign of the former section. 
In the placement 2 the basic wall is excited to vibrations little affected by the secondary wall. 
Therefore the sound level performance of the arrangement 2 should reflect the middling performance of 
the basic wall as it has been measured in the placement 1. 
Due to the reason explained above it was rather worse. 

37 
 
 
 
 
 
 
 
 
 
 
In the placement 3 the basic wall is passive and the performance of the wall connections in relation to 
the transmission of vibration is known to be low. 
A  heavy  disturbance  of  the  sound  conditions  by  supplementary  surfaces  in  the  measurement  room 
cannot happen. 
What happens in the mounting room due to the supplementary wall can only affect the airborne sound, 
which is effectively annihilated by the acoustic mineral wool inside. 
Indeed taking a look at the Fig.67 and 68 the supplementary walls divide the mounting room nearly in 
two rooms and must influence the airborne conditions in it. 
Fig. 68 shows the case of the connection D where the second wall is fastened to the basic wall aside of 
the steel frame. 
Therefore we can expect more success from the third campaign than from the others. 

The following programme has been carried out 

1.  Usual  steel  frame  (see  Fig.  5  left  and  also  section  4.5),  single  planking  GB  or  GF,  thickness 

12.5 mm  

2.  Usual steel frame, double planking thickness GB or GF (12.5 +10.0) mm 
3.  Frame with slit C-profiles (see Fig. 5 right), single planking GB or GF, thickness 12.5 mm 
4.  Frame with slit C-profiles, double planking GB or GF, thickness (12.5+10.0) mm 
5.  Usual steel frame, one side double planking GB or GF thickness (12.5+10) mm, other side OSB 

thickness 19 mm 

The three connections already used in the placement 2 have also been utilised in the third campaign, 

1. 

2. 

3. 

Connection of the two perpendicular walls on a C-profile of the basic wall “hard”  
(Fig. 63  A) 
Connection of the two perpendicular walls on a C-profile of the basic wall “elastic” using 
an elastic interlayer between the walls (Fig. 63 C) 
Connection of the two perpendicular walls on a position between the members of the steel 
frame (Fig. 63 D) 

4.15.1  Results related to measurement placement 3  

The results are compiled in the tables 23 and 24 for the wall connection A, in the tables 25 and 26 for 
the wall connection C and in the tables 27 and 28 for the wall connection D. 
If we have a first glance at the tables we become aware that in some wall and connection variants the 
value of the airborne sound level and of that the attached pipe produces are equal. 
Of course due to the scattering of the experimental handicraft this correspondence is already fulfilled in 
a reasonable limit of  1 dB. 
In  addition  because  human  cannot  distinguish  sound  level  differences  smaller  than  1  dB  it  is  a  good 
approach also from the point of view of human comfort. 
In  table  29  the  difference  values  of  the  measured  sound  level  produced  by  the  attached  pipe  to  the 
airborne sound level are compiled. To measure the airborne sound level the pipe is disconnected from 
the wall and vibrates free only fastened to the lab envelope aside from the test wall. 
A  difference  smaller  than  1  dB  is  a  good  criterion  for  the  non-transport  of  vibration  energy  by  the 
connection.   
We can state that a secondary wall bearing the water feeding pipe and the noise source transmits only a 
small part of its vibration energy generated by the fitting to the main passive basic wall perpendicularly 
attached to it. In the best case no vibrations are transmitted. 
The different connections A, C, D have different qualities. 
A hard connection of both walls on a C-profile of the basic main wall (connection A) should be used 
only for double-planked walls. 
The  double-planked  wall  with  conventional  steel  frame  is  rather  better  than  the  wall  with  split  C-
profiles staying 0.1 dB above the limit of  1 dB 
The  connection  C  further exploiting  a C-profile  position  for  joining  the  two  walls  but  with an  elastic 
layer between the walls doesn’t transmit vibration energy from one wall to the other independently of 
the nature of the wall. 

38 
 
 
 
 
 
 
Using the connection C single and double-planked walls can be used. 
The last connection D- should benefit from the elastic properties of the planking and was assumed to be 
nearly comparable with the C-connection. 
Nevertheless the experimental values show a marked worsening of the results in comparison with the C-
connection. 
In the light of the relation to the first connection A, which is also a hard connection but on a C-profile 
the D-version becomes more favourable. So the elastic properties of the wall play a certain role. 
It is surely unquestionably that a D-connection with an elastic interlayer shows also excellent results. 
The D-variant is important because it is not simply a third connection version but allows a free design 
of the rooms. 
The last table 29 of the third campaign considered the transport power for vibration energy of the wall 
connections in relation to the wall design. 
The tables 23-28 compile the absolute sound level values for the different walls and connections. 
A connection must not prevent the transport of power absolutely but reduce the sound level down to an 
acceptable value. 
In this sense the mentioned tables give the absolute value of the sound level reduction of a noise source 
generating a calibrated noise of 46,8 dB. 
If the current fitting source has a known noise level lower than that of the INS a weaker wall design can 
be also used. 
If we look at the tables 23, 24 containing the results of the A-connection the two double planked walls 
with conventional and split steel frame win the race. 
They have the same performance in the question of the reduction of airborne sound but the conventional 
steel frame wins the race concerning the fitting noise transport trough the wall. 
It  is  a  good  result  because  the  conventional  steel  frame  is  cheaper  than  a  special  frame  but  having  a 
better performance. A sound level reduction of about –14 dB means that a source generating a fitting 
noise of 44 dB is weakened to the wanted sound level limit of 30 dB. 
Adding  an  interlayer  between  the  partners  of  the  junction  every  wall  design  brings  good  and  best 
results. 
Again the conventional steel frame double planked reaches the best results, but a second competitor, the 
double planked (GB or GF) with OSB as second partner on the other wall side becomes better than the 
walls with slit profiles. 
OSB  is  the  mainly  used  material  in  the  USA  and  begins  to  start  in  Europe.  Perhaps  some  sorrows 
concerning  the  emanation  of  formaldehyde  should  be  a  reason  for  the  low  sale  volume.  Indeed  it  is 
usually used in Germany for the roof part of the house and not for the day rooms. 
According to the first remarks concerning the D-connection the results are weaker than the results of the 
C-connection but finally still good. 

4.15.2  First conclusions 

1. 

2. 

3. 

4 

5. 

The third placement brings the best performance in relation to the transport of vibration energy 
by the wall connection.  Due  to  the  established  low  transport  performance  of  every  analysed 
connection a vibrating secondary wall cannot transport considerable vibration energy to a main 
passive wall via one end single joint. 

The double-planked walls mostly bring a dominant performance over all the wall connections in 
comparison to the single planked walls. 
Nevertheless all the wall designs reach good absolute sound attenuation values. 

Due  to  the  placement  of  the  secondary  wall  in  the  mounting  room  any  disturbances  of  the 
measurement conditions in the microphone room don’t take place. 

A  possible  influence  of  the  airborne  sound  in  the  mounting  room  has  no  impact  on  the 
microphone room because it is successfully annihilated by the acoustic mineral wool inside the 
wall. 

The connection C (joint on a C-profile of the basic wall, with elastic layer between the walls) 
doesn’t transmit any vibration energy for all the wall designs.  

39 
 
 
   
 
 
 
 
4.16 

Silencer 

If  we  strike  the  balance  after  the  three  measurement  campaigns  we  have  one  arrangement  with  very 
successful  solutions  (placement  3)  and  one  arrangement  with  a  mediocre  improvement  of  the  fitting 
noise reduction of maximally –5,3 dB (placement 1). 

The  term  mediocre  concerns  the  logarithmic  quantity  “sound  level”.  The  physical  energetic  quantity 
“sound pressure square”, which is generated by the wall vibration has been reduced by 70%.  
So  acoustics  is  a  very  thankless  field  because  all  the  quantities  are  compressed  by  the  logarithmic 
behaviour of human hearing. 

The placement 2 failed due to the experimental reasons discussed in the section 4.14.2. 
Of  course  the  placement  3  cannot  be  realised  in  every  house  design  nor  can  it  be  imposed  to  every 
customer. 

Therefore solutions to reduce the vibration energy of the feeding circuit before it is introduced into the 
wall by the fastening have to be found. 
This is the scope of the so-called silencers. 
At first we call every measure suitable to reduce the sound level of a fitting, which is not a construction 
element of the basic wall modules as they have been categorized in Fig. 5 a silencer. 

A basic module consists of  

1.  A steel frame of vertical C-profiles split or not and two horizontal U-profiles on which the C-

profiles are fastened to produce a stiff skeleton, 

2.  A layer of boards single or double on both sides of the skeleton,  
3.  Acoustic or thermal mineral wool inside.  

A primary silencer is a measure suitable to reduce the fitting noise acting directly on the feeding system 
without changing anything in the wall. The sound level of the fitting itself is constructional and cannot 
be modified without destroying its initial design.  
A secondary silencer is a measure adding any element to the basic wall defined above. 

4.16.1  Primary silencer 

To  the  column  primary  silencers  belong  simple  measures  like  the  jacketing  of  the  pipe  with  acoustic 
foam, sound barrier design and embedding means of high internal friction. 

4.16.2  Pipe jacketing   

The pipe jacketing has never been a planned measure to reduce the fitting noise. At the beginning of the 
project we had some worries that the long pipe along the lab envelope of a length of about 7 m (total 
length allowed by the EN ISO 3822-1 < 10 m, see Fig. 11) should generate an unreasonable airborne 
sound level. 
So the pipe part aside of the measuring line was wrapped up in acoustic foam of density 120 kg/m3. 
Finally the whole pipe inclusive the part of the pipe attached to the test wall was wrapped up 
The single planked basic wall in the placement 1was used for the measurements. 
Table 30 shows the obtained results. Jacketing the pipe along the lab wall reduces the airborne sound 
level by -3 dB or halves the sound pressure square. The impact on the transmitted vibration energy is 
lower namely –1,5 dB. 
The complete jacketing of the pipe including also the part fastened to the test wall reaches a lowering of 
the vibration power of the pipe by –4,8 dB. This is a really high value. 
Because  it  was  a  fast  trial  outside  the  plan  the  measurement  of  the  airborne  reduction  has  been 
forgotten. 
After  all  the  airborne  sound  of  the  total  length  of  the  pipe  is  due  to  the  vibration  of  the  fitting  or  its 
reference source the INS and belongs definitively to the sound level caused by the source. 

40 
 
 
 
 
 
 
 
 
 
 
 
 
In addition we wanted to remain as near as possible to the EN ISO 38221 prescribing a bare steel pipe. 
Therefore after the end of the trials the jacketing was completely removed. 
Afterwards we have started the project performing the first trials related to the later subject silencers. 
On the market pipe jackets for thermal insulation for warm water feeding pipes are available only. 
So in any case the covering of a water pipe with acoustic foam stripes must be done by handicraft. 

4.16.3  Sound barriers 

A sound barrier is actually another name for silencers. In the project it is related to a family of designs 
based on long bows available on the market making use of the elastic properties of the material. 
A silencer should consist of an arrangement and a damping material. A sound barrier should try to reach 
a sound reduction only by a smart arrangement. 
Nevertheless these are only secondary features also of secondary significance. 

The first step before a sound barrier is drafted consists in the understanding what the pipe really does. 
Due to the complexity of the features simulation procedures are predestined to cast light on the matter. 
So the vibration behaviour of the pipe has been analysed by means of the FEM first. 
In  a  second  step  the  different  sound  barriers  have  been  simulated  and  their  suitability  to  reduce 
vibration modes has been analysed. 

4.16.4  FEM calculation of pipe vibrations 

Fig.  69  represents  the  basic  physical  arrangement  with  the  correct  positions  of  the  clamps  and  one 
elbow at which prolongation the INS is attached. 
Fig. 70 reveals three of the possible modes whose appearance can be graphically presented, transversal 
modes in two perpendicular directions x, y and thickness modes. 
In addition there are longitudinal and torsion modes as well as  mixed modes of the above mentioned 
single modes. 
In Fig. 71 a compilation of all modes of the basic experimental arrangement in Fig. 69 has been made. 
Fig.  72  shows  a  mixed  mode  at  1038  Hz  (thickness  mode  +transversal  mode  tr(x))  and  a  transversal 
mode tr(y) at 3945 Hz where the pipe displacement has been drastically exaggerated to make it visible. 
From  the  sound  propagation  point  of  view  it  becomes  clear  that  pipes  are  excellent  resonators  being 
able to transmit every kind of vibration generated by noise source under every boundary conditions. 
Obviously  the  pipe  is  always  able  to  find  a  vibration  mode  whose  zero  crossing  coincides  with  the 
clamping conditions, so that the pipe can transmit the sound further. 

4.16.5  Sound barrier design, improved model for pipe vibrations 

The starting work of pipe vibration analysis is based on the eigenfrequency analysis of the empty pipe. 
The elemental processing of the implementation of water via the introduction of a resultant density was 
not taken into consideration because it did not improve the quality of the model. 
Indeed pipe vibrations are generated mainly by pressure oscillations of the water column in the pipe, so 
the more complex mechanism got started.   
The  traditionally  used  excellent  software  package  MARC/MENTAT  by  FQZO  came  to  itslimits  very 
fast.  The  implemented  liquid-solid  module  failed  because  it  has  been  never  been  improved  by  MSC 
since the beginning of code writing.  
Obviously the strong point of MARC concerns the mechanical static calculations with an excellent pre- 
and post-processing environment for customer. 
So the use of a NASTRAN package became mandatory. NASTRAN has been developed in the sixties 
in  the  time  of  frame  computers  using  punch  cards  and  the  outfit  has  never  changed.  Pre-  and  post 
processing is rather poor in comparison with MARC and other modern FEM-codes.  
The structure of input dates remains an image of punch card, so the learning curve for using NASTRAN 
is long, also for people skilled in FEM-processing. 
In return the solid-liquid coupling module works clearly and excellent, so the targets were performed 
straight forward. 

What are the effects of coupling? 

41 
 
 
 
 
 
 
 
 
- 

- 

- 

A fluid, which is completely enclosed by the structure, has a stiffening effect on the structure. 
This effect is proportional to the bulk module and inversely proportional to the closed volume 
of the fluid 
The  inertia  of  the  fluid  increases  the  mass  of  the  structure.  This  effect  is  proportional  to  the 
mass density of the fluid 
The  vibrations  become  coupled.  They  reflect  the  influence  of  the  fluid  on  the  structural 
vibrations.  The  eigenvalue  problem  becomes  unsymmetrical  but  the  eigenvalues  and 
eigenvectors not. 

Modelling of coupled problems starts with the separate meshing of the pipe and water volume (see Fig. 
73-pipe: magenta, water: red). Then the nodes of both meshes coming in contact are coupled.  
In MARC the pipe and the adjacent water node are fused to one node and obviously this generates a 
problem  of  new  definition  of  the  mechanical  properties  of  the  node.  In  NASTRAN  a  new  material 
formulation for both nodes is created without fusing them. 
The target of these sophisticated calculation consisted in the searching of possibilities to influence the 
vibration  behaviour  of  pipes  against  the  background  of  sound  attenuation  and  simulation  closed  to 
reality. 

The former section made clear, that pipes are excellent oscillators being able to evade almost fastening 
constellations because the number of modes is so high that there is always a mode, which can fit almost 
boundary conditions. 
The addition of water doesn’t influence this property more than in relation to the eigenmode frequency 
values 
So the unique solution if at all existent seems to base uniquely in a new design of pipe arrangement. 
A possible design must be realisable on the base of existent market components without exceptions if it 
wants to get a future. Therefore design possibilities are restricted to the palette of available commercial 
components and they are only few. 
To avoid eddies the so-called long bends G4 (radius 60 mm) according to ISO 49 have been used. In the 
following all the combinations of these elements are called sound barriers. The simplest element with 
barrier function is shown in Fig. 74 In more details. It consists of two long bends G4 assembled to a 
half bow (B1). 
Design  target  was  to  look  for  possibilities  of  mode  number  reduction  and  control  of  the  vibration 
frequencies if possible. 
Because  the  measuring  pipe  always  vibrates  as  a  whole  the  basic  solution  consists  in  introducing 
elements, which modify the vibration spectrum and its amplitude.  
The family of barriers based on commercial components G4 is shown in Fig. 75 where P0 is the “canna 
vulgaris”, i.e. the simple pipe as reference secondary sound generator. The primary sound generator is 
the fitting, in our case the INS.  
If the concept is carried out straight forward, the next arrangement expected to be better than a simple 
barrier B1 consists of two half bows one behind the other (B2).  
The  third  also  consists  of  two  bows  but  in  an  angle  of  90°  to  another  (B3).  Because  of  the  rotation 
symmetry  of  the  pipe  there  are  modes  of  equal  frequency  in  x-  and  y-direction,  so  it  makes  sense  to 
study  the  properties  of  barrier  elements  shown  in  Fig.  76  to  counteract  the  same  modes  but  in  two 
displacement directions. 
Last  but  not  least  two  bows  in  180°  one  to  the  other  complete  the  palette  of  possibilities  based  on 
commercial components (B4) in Fig. 77. 
The  modal  analysis  gives  an  information  about  the  number  of  vibration  possibilities  of  a  body,  the 
modes  and  the  frequency  at  which  they  response  to  an  excitation,  i.e.  the  spectral  density  of  the 
spectrum. 
The overall view of the results is presented in Fig. 78. 
Obviously B2 barriers (see Fig. 75) vibrate coherent by with the pipe, so there is no difference between 
the spectrum of the simple pipe and the above- mentioned arrangement. 
First the arrangements of two B1 barriers with an angle between 90° and 180° generate the effect found 
out in the analysis of the components as such.    
The most remarkable and also expected effect comes from the B4 barrier. 

42 
 
 
 
In  a  second  step,  the  distribution  of  the  intensity,  which  is  proportional  to  the  amplitude  square, 
becomes important. 
Fig.  79  shows  the  spectral  vibration  amplitude  (SA)  for  the  single  pipe  revealing  excellent  vibration 
properties over the whole range of frequencies between 24.7 and 14157 Hz for the first hundred modes. 
In Fig. 80 we start with the introduction of two B1-barriers. 
Obviously the bow components work like a frequency filter in dependence of their arrangement. In the 
case of full symmetrical arrangement, the vibration spectrum at both clamps CP1 and CP2 is equivalent 
(see Fig. 78, arrangement: +P1+P1, full red squares).  So in the overview picture there is no difference 
between the full symmetrical arrangement and the single straight pipe spectrum. 
The first marked improvement is reached rotating one of the two B1-barriers in quadrature because of 
the symmetrical vibration modes in two perpendicular directions perpendicular to the pipe axis (see Fig. 
81).  
Comparing the amplitudes of the remaining spectra the arrangement with two double B4 barriers (see 
Fig.  82)  reduces  the  number  of  modes  giving  a  remarkable  contribution  to  the  filtering  of  vibration 
energy of the inaugural pipe P0. 
All the calculations have been done without a supplementary damping of the sound barriers. Without 
damping  a  filter  suppresses  vibrations,  which  don’t  match  its  own  eigenfrequencies.  All  the  other 
frequencies pass through. 
Obviously the best performance is reached by arrangements with a relatively large space requirement.  
FEM can give the reduction of vibration modes but not its impact on the sound level value. 

4.16.6  Sound level reduction by sound barrier 

The basic element of the silencer family B1 (see Fig. 83) was taken for the experimental work because 
it  needs  the  smallest  space.  It  was  coincidentally  used  with  the  wall  arrangement  W9F_10,  the 
earthquake version according to the Turkish earthquake standard (see Fig. 32) 
The effect of the silencer  on the reduction of sound level is reported in Table 31. In the hierarchy of 
silencers it has the lowest reduction performance related to the FEM-evaluation.  
Nevertheless it is the reference point for the silencer family.  
Because the higher configurations of sound barriers consist of further silencers B1 connected in series    
the total reduction of the sound level L can be given in good approximation by the simple relation 

L = L1+L2+…+Ln  

   (10) 

where Li is the attenuation of the i-th silencer B1. 

At a first glance the sound level reduction is rather weak. The A-corrected reduction amounts roughly 1 
dB.  According  to  the  relation  (17)  a  sound  barrier  consisting  of  two  B1  silencer  (see  Fig.  75)  should 
reach 2 dB or slightly more. 
The sound reduction power of this simple arrangement can be improved by embedding the silencer in a 
material, which neutralises the vibration of the silencer, whose arrangement is given by the Fig. 84. 
This is surely a more effective way than using other silencer of the family requiring more space 
For this purpose different granulated materials with a different bulk density have been used. 
The results are presented in Fig. 85. The materials are commonly used in the refractory metallurgy, so 
they were available in the surrounding of the plant. 
All the materials were sieved to have a tight particle size spectrum. 
The diagram shows a clear dependence of the reduction of the sound level with the increase of the bulk 
density up to 2,18 kg/litre. 
If we look at the reduction of the sound intensity the use of corundum grain reduces the sound intensity 
to 43% of that of the silencer alone. 
A very interesting comparison is given between the maximum reached reduction of the sound level by 
silencer and by soft coupling of the INS to the pipe in the last line of table. 
We can conclude that the silencer with supplementary damping has reached the full elimination of the 
mechanical vibration of the pipe, so that only the action of pressure and whirl shocks generated by the 
water flow remain. These features cannot be reduced by mechanical measures. 
Therefore  the  higher  bulk  density  of  granular  high  cast  iron  tested  at  the  end  of  the  trials  could  not 
achieve more. 

43 
 
 
 
 
 
 
 
 
 
 
 
 
 
The small difference of 1.2 dB may result from the different walls from which the measurements have 
been made. 
Finally  the  simplest  and  smallest  barrier  B1  can  annihilate  the  mechanical  vibration  of  the  pipe  by 
means of supplementary friction rich material of bulk density of about 2.0 kg/litre completely.  
Soft coupling in water feeding systems is always the weakest element of the circuit and responsible for 
the most water damages per year. It is a long-term source of danger deteriorating slowly until it fails 
suddenly. 
Therefore a hard connection with the same properties is always highly recommendable. 
So it can be concluded from this section that using a primary silencer the mechanical vibrations of the 
fitting can be suppressed causing a reduction of the sound level of about –4,5 dB.  
On the other hand a complete jacketing of the pipe with the special acoustic foam with a density of 120 
kg/m3 also reaches the same result. 
This means that the three measures carried out act on the same physical entity. Because the silencer B1 
acts like a spring in the axis of the pipe (see Fig. 83), longitudinal vibrations are obviously cushioned 
without weakening markedly the perpendicular motion of the pipe.   

4.16.7  Secondary silencer I 

A  secondary  silencer  is  a  measure  adding  any  element  to  the  basic  wall  defined  in  4.16.  So  the  wall 
design changes from a commercial customary product to a new product.  
Because we can distinguish between two different groups of measures carried out in the project we treat 
the  subject  of  secondary  silencers  in  two  separated  sections  “Secondary  silencer  I”  and    “Secondary 
silencer II”. 
The  planned  activities  concerning  secondary  silencers  were  focussed  on  the  self-annihilation  of  the 
vibration energy by connecting the opposite inner walls by metallic or damping stripes. 
The results of the FEM calculations revealed as expected, that there are slightly different frequencies of 
the  modes left and right from the central C-profile  due to the generic asymmetry of the member in  a 
panel. 
So connecting both sides crosswise the different frequencies would generate an incoherent transport of 
energy and therefore a self-annihilation. 
The next FEM result in connection with the vibration measurements contradicted already this strategy 
because it was proved that the wall vibrates as a whole and not the single panels although the vibration 
energy is introduced into the single panels. 
After having established experimentally the dominant transport path of the vibrational energy over the 
webs of the U-profiles it made no longer sense to continue with this activities. 
Nevertheless  the  question  of  the  effectiveness  of  secondary  silencers  was  still  to  be  answered.  The 
possibility to disturb the sound emanation by the wall in the microphone room adding other different 
measures was studied. 
The role of secondary silencers I is to receive vibrational energy from the wall without giving it back to 
the exciter. This is realised by the damping of the energy shifted to the secondary silencer and by the 
mass relation between secondary body and first. 
When the mass of the second body is rather lower than that of the exciter source the energy from the 
secondary body is reflected back from the heavier body and not transmitted back to the exciter.  
In this section the performance of different measures are analysed and discussed. 
To reduce the amount of work the secondary silencers have been fixed on the outside of the wall. In a 
commercial version they are fixed inside  the wall between the stripes of mineral wool. 
For convenience we used the wall already installed, the wall W9F_10. 
Fig. 86 shows the different variants for secondary silencers used. The variant (a) and (b) differ only in 
the number of screws between secondary C-profile and wall.  
In the variant (a) the C-Profiles haven  been fastened to the wall  only at both ends, in the  version (b) 
according  to  construction  standard.  In  the  version  (c)  the  C-profiles  are  filled  with  mineral  wool  as 
damping agent. 
The version (d) consisted in elastically glued and screwed timber slabs. With the diagonal arrangement 
the appearance of modes of the exciter wall should be prevented. 
Table  32  compiles  the  total  of  the  experiments  carried  out.  Because  the  value  for  the  uncorrected 
equivalent sound level in the case of the wall without silencers (first column) was unexpectedly high, 

44 
 
 
the  values  for  the  total  sound  level  uncorrected  and  corrected  has  been  calculated  from  the  sound 
spectra and introduced in brackets to the values delivered by the device. 
In any case it is not a typing mistake because every result consists of the average of three independent 
measurements at different microphone positions, which differ less than 1 dB from another. 
In other fortunately rare cases a discrepancy between the global values delivered by the gauge and the 
values  calculated  from  the  spectra  also  delivered  by  the  device  was  found  without  finding  out  any 
explanation. 
The results of table 32 are worse than that of the reference wall without exception. 
The  last  trial  where  timbers  were  screwed  and  stuck  on  the  board  pursued  another  target.  If  we  are 
aware  of  the  FEM-fig  50  and  following,  the  two-dimensional  mode  structure  is  oriented  to  the 
rectangular edge of the plank. 
With  the  oblique  fastening  of  timber  we  wanted  to  prevent  the  formation  of  regular  vibration  modes 
according to the results of the FEM calculation and expected a clear improvement of the sound level 
value. 
Indeed  the  result  is  better  than  that  all  other  ones  in  table  30  but  not  better  than  that  of  the  unarmed 
wall. 
In  Fig.  87  the  spectra  of  the  analysed  secondary  silencer  of  type  I  are  presented.  They  confirm  the 
values for the total sound level.  

4.16.8  Further examination of the results 

This  unexpectedly  unsatisfactory  situation  required  further  examinations  to  find  or  to  reject  the 
assumption of a systematic mistake worsening the results. 
The mounting room where the pipe excited by the INS generates the fitting noise has no tilted walls in 
comparison to the adjacent measurement room. 
The question was whether some high intensity room modes are generated in the mounting room by the 
airborne sound finally causing the indifferent results of table 30 or not. 
The  standard  EN  ISO  3822-1  doesn’t  mention  the  airborne  sound  (AS)  the  pipe  radiates  into  the 
mounting room, which is reflected on the walls and passes through the wall to the measurement room.  
It  prescribes  only  the  areal  density  of  the  wall  bearing  the  pipe  producing  noise  but  not  the  sound 
properties of the wall surface. Reflection or transmission properties for the airborne sound have not to 
be defined. Due to the great mass of the wall it is assumed that airborne sound doesn’t play a role in the 
evaluation of fitting noise. 
The  standard  deals  solely  with  the  conditions  to  be  kept  in  the  measurement  room,  which  have  been 
also  followed  in  the  project.  The  area  where  the  pipe  is  working  is  not  subject  to  further  rules. 
Obviously what happens there is of secondary meaning for the results in the measurement room due to 
the high mass density of the wall between the measurement room and the pipe. 
The situation is quite different in the case of light gauge walls. 
In  the  end  the  fitting  generates  also  the  airborne  sound,  so  it  is  part  of  the  fitting  noise.  But  at  the 
moment at which the mounting room works as resonator causing an amplification of the noise by room 
modes we obtain wrong results. 
Therefore  the  airborne  sound  has  been measured  again  in  the  mounting  as  well  as  in  the  microphone 
room supplementary by disconnecting the pipe from the clamping.  
Indeed it is always a bad measurement because if the pipe is disconnected from the clamping it vibrates 
with the whole free length. 
So the airborne sound level generated is surely different from that of the clamped pipe. 
Because the clamped pipe transmits the main part of its energy to the wall the airborne sound level of a 
clamped pipe must be lower than that of the free floating one. 
In any case it is a good indicator for what sound the INS attached to a resonant system, the free-floating 
pipe produces. 
The target was to measure the appearance of room modes in the mounting room measuring the sound 
level  in  the  mounting  room  at  different  microphone  positions  and  heights  where  room  modes  were 
supposed to be detectable.  
Room modes are generated at the frequency  according to  

45 
  
 
 
 
 
2   ny

2 
2    nz

       c         nx
  =          +  +    
       2          L2    W2   H2 

            (11) 

where c is the sound velocity in air, nx, ny, nz are the mode number in the main directions and LxWxH 
the room volume. 
Fig. 88 shows the spatial structure of the first modes in the longitudinal direction. 
The  meaning  of  room  modes  is  not  only  the  perception  of  some  beats  at  low  frequency  but  also  the 
increasing of the sound intensity at the higher harmonics of the basic room modes in compliance with  

          cm        nx
m  =           +  +   
            2           L2     W2   H2 

2 
2    nz

2   ny

              (12) 

with m = 1,2,3,… 
To  detect  room  modes  the  sound  in  the  mounting  room  must  be  measured  at  different  positions 
according to the field distribution of the sound field.  
Because  the  sound  field  distribution  of  the  higher  modes  becomes  very  fast  very  tight  microphone 
positions are used where the measurement of the first modes should be successful. 
For  the  sound  measurements  the  pipe  has  been  unclamped  to  have  only  one  clear  source  of  sound. 
Although  the  clamped  pipe  must  generate  another  sound  field  together  with  the  vibrating  wall  with 
which it exchanges vibration energy, the total field energy and therefore the maximum intensities of the 
field must be similar because the total sound field energy remains the same. 
It is only shared between different bodies. 
Table  33  gives  an  overview  about  the  first  room  modes  calculated  from  Eq.  11  referenced  to  the 
dimensions of the mounting room. 
Obviously the low frequency modes should be detectable because the bandwidth of the low frequency 
one-third-octave is relatively small. 
Fig. 89 shows all the microphone positions in the mounting room for the measurement of room modes. 
Fig. 90 gives the total of the sound level measurement at all  nine microphone positions. 
The red arrows are positioned at the one-third-octave frequency 31.5 Hz and 80 Hz, 
the yellow arrow at 63 Hz. 
At f = 31.5 Hz there is a textbook like minimum of the sound level corresponding to the room mode 
{1,0,0} at the three microphone positions 4,5,6 (see Fig. 89) in the middle of the room according to the 
mode amplitude distribution in Fig. 88(a). 
Obviously there are no modes in the  {0,1,0} or  {0,0,1}-direction because they had to be present in the 
one-third-octave at 63 Hz (yellow arrow in Fig.90) as well as oblique modes of type {1,1,0}. 
The next drop down of the sound level appears at one-third-octave of 80 Hz where mainly high order 
oblique room mode frequencies are present. 
Nevertheless above 100 Hz no mode related structure of the sound level could be identified. 
Looking  at  Fig.  90  we  can  state  that  in  the  mounting  room  an  average  sound  level  over  the  nine 
microphone positions of about 50 dB up to 8000 Hz exists. 
The recorded sound level in the microphone room belonging to that measured in the mounting room is 
shown  in  Fig.  91.  Like  the  other  measurement  it  is  the  averaged  curve  over  the  three  different 
microphone positions used for all measurements in the measuring room. 
Obviously the mineral wool inside the wall makes its job properly. So we can establish that no artefacts 
produces sound of high level especially in the range around 4000 Hz and more and the sound level of 
50 dB and more in the mounting room is attenuated below 20 dB in the frequency range above 2000 
Hz. 
The  last  undertaking  to  explain  the  discrepancy  between  mechanical  and  sound  level  resulted  from 
some  hints  in  the  literature4  that  the  sound  field  can  generate  higher  modes  vibrations  at  higher 
frequency in the wall. 

4 H. Babovsky, Berechnung des Schalldrucks im innern eines Quaders, Universität Kaiserslautern, 1985 

46 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
                                                 
Indeed the sound field in the  measurement as well in the  mounting room is reflected on the opposite 
wall and comes back to the inaugural source as secondary sound field able to act as exciter. 
UPM started first calculations of sound propagation simulation in the measurement room to prove the 
literature statement based on simplified room model to reduce the amount of work.  
Fig. 92 shows the development of sound pressure propagation for the fourth time increment of a sinus 
shaped  monochromatic  source  at  1000  Hz  0.0275s  after  the  sound  source  started  as  example  for  the 
calculation done. 
The  difficulty  of  the  simulation  arises  from  the  lack  of  knowledge  about  the  physically  real  phase 
information of the sound wave to take into account. Therefore the addition of the wave front running 
from the wall and coming back at the microphone position suffers from these imponderables. 
Nevertheless  at  this  level  of  knowledge  no  excitation  of  higher  modes  by  the  basic  wave  frequency 
should be established. 
The benefit of all these sometime hard work was to ensure theoretically, that no fundamental artefacts 
were the origin of the measured sound level in the lab. 

4.16.9  Secondary silencer type II 

Secondary silencers of type II concern further measures modifying the characteristic of the light gauge 
wall  by  additional  materials  but  differ  in  the  target  as  well  as  in  the  nature  of  the  measure  from  the 
secondary silencer of type I in the last section. 
It has been already established that walls bearing the water feeding system should be double planked. 
On the other hand the obtained results compiled in table 13 were rather unsatisfactory.   
It was suspected that the poor performance of the wall should arise from the possibility that the double 
planking didn’t act as one board of double thickness (strictly 12.5mm+10mm) but that the boards were 
vibrating independently from each other. 
This was conceivable because only the first panel is screwed to the steel frame whereas the second is 
simply screwed on the first along the edges. 
So the general target of this complex was to make sure that the both panels were vibrating together as 
one panel of double thickness. Finally some further versions were also carried out.  

4.16.9.1 Wall with anti-drum tape on both panel inner sides (see Fig. 93, 94) 

TECOBAND 220 80 x 1,9 mm/0,5m is a product used in the car and truck body to reduce the impact of 
motor vibrations on the sound level in the cabin.  
As it can be seen in Fig. 93 the stripes of TECOBAND have been adhered to the panel inner sides of 
both wall sides according to the draft of Fig. 94. 

4.16.9.2 Wall with anti-drum tape between the panels in the wall side facing the measurement 

 room (see Fig. 95) 

From the engineering feeling point of view , the first trial should seem surely a little bit senseless.  
It  is  more  understandable  that  the  stripe  between  the  panels  of  the  double  planking  could  be  more 
successful. The introduced vibrational energy in the panel screwed to the members forcing it to wave is 
transmitted  to  the  second  board  by  the  first  one  via  a  non-elastic  layer  whose  purpose  is  exactly  to 
counteract this action. 

4.16.9.3 Wall with impact sound foil between the panels facing the measurement room  

 (see Fig. 96) 

Instead  of  stripes  a  continuous  special  foil  for  impact  sound  with  a  thickness  of  2  mm  has  been 
introduced between the two panels planked facing the microphone room. 
Fig. 96a shows the impact sound layer mounted on the panel screwed to the members. In Fig. 96b the 
second panel has been screwed on the first one. 
The sound level of an infinite short impact has a mathematical frequency spectrum from zero to infinity. 
Therefore  materials,  which  are  suitable  to  reduce  sound  impact  have  a  broad  frequency  absorbance 
capability which is perhaps not so efficient in a defined frequency range as that of anti drum materials 
but in return useful at all. 

47 
 
 
 
 
 
    
 
 
 
4.16.9.4 Wall like 4.16.9..3 but additionally screwed (see Fig. 97) 

The  panels  have  been  additionally  screwed  according  to  the  raster  of  Fig.  97.  The  results  of  the 
preceding trial seemed to indicate, that the two panels didn’t vibrate together. 

4.16.9.5  Wall with acoustic foam foil between the panels facing the measurement room (see Fig. 
98) 

The trial is comparable to 4.16.9.3 using now explicit acoustic foam layer with the thickness of 5 mm. 

4.16.9.6 Wall W2F partition layer (see Fig. 99) 

In the dry lining technology palette there is a lot of commercial tapes based for example on closed soft 
polyethylene  foam  designed  to  be  introduced  between  metallic  member  and  board  to  reduce  the 
vibration transport between board and members and vice versa. 
One of them was used in the project to achieve an improvement of the sound level value.  
It was adhered to every C- and U-profile on both sides of the wall. 

3.16.9.7  Wall W2F with split boards (see Fig. 100) 

In this version the board bearing the pipe has been split into three parts. The idea was to separate the 
vibrational  part  of  the  board  from  the  rest  of  the  wall  so  that  there  would  be  only  a  low  vibration 
transmission via the C-profiles to the wall. 
The splitting of panels is a usual practice in dry lining if it makes the work easer. Because the walls are 
wallpapered at the end of the job there is no inhibition to do it. 
The small slits between the parts were soundproofed with caulking compound „Aerostat – IX“ (Vehicle 
body sealant, permanently plastic and kneadable) on both sides.  
This caulking was used in the whole project for all the soundproof works.  

3.16.9.8  Wall W2F with split boards, filled  

In  this  experiment  the  mineral  wool  was  removed  and  the  hollow  was  filled  completely  with  sound 
insulation granules FIBOPHON (maxi CLAY AS 102) with a grain size of 0 to 2 mm.  
The  material  is  expanded  clay  with  a  density  of  600  kgm-3  and  is  used  mainly  for  impact  sound 
insulation. 
It is rather lighter than sand, so the danger was minor that the screw connections of the boards to the 
members 
failed. 
Due to the granular consistency of the filling an intergranular friction effect would take place reducing 
or annealing the vibrational energy of the boards in contact with the material. 
A positive side effect must come into being due to the increasing of the total mass from 610 kg to 1071 
kg of the wall transforming it into a “massive” wall. 
Nevertheless  looking  to  the  absolute  values  for  the  weight  of  the  walls,  dry  lining  walls  are  not 
lightweights.  
The mass which must be put in move by the pipe increases only by about 1,7 times.  

4.16.9.9 Results summary 

Taking  a  glance  at  the  table  34  where  all  the  values  of  the  total  sound  levels  for  all  trials  of  section 
4.16.9  are  collected,  the  results  show  a  good  progress  in  the  right  direction.  We  move  already  in  the 
range below 40 dB down to 36 dB using after all a noise source generating a sound level of 46,8 dB.  
According  to  table  34  there  are  three  variants  reducing  the  sound  level  of  the  original  arrangement 
(4.16.9.1,  4.16.9.6  and  4.16.9.7)  and  five  variants  whose  application  cause  a  negligible  effect  or  an 
enhancement of it. 
In a first step it must be cleared what bad measures do and what good measures don’t do. 
In Fig. 101 the A-corrected best variants together with the sound level of the original wall W2F-10 (W) 
Wall  (2) Double planked (F) Fibreboard, (1) placement 1 (0) no wall connection) are shown. 

48 
 
 
  
 
 
 
 
 
 
 
 
In this figure and in the next the spectra are presented in the linear frequency scale because the effects 
are more visible than in the logarithmic one. 
The  original  wall  spectrum  with  an  A-corrected  total  sound  level  of  42,3  dB  shows  dominant  values 
over all frequencies. 
The  good  variants  reduce  the  sound  level  in  the  frequency  range  higher  than  2000  Hz  and  keep  the 
contribution  of  the  sound  level  between  0  and  2000  Hz  below  that  of  the  original  wall  or  reduce  it 
drastically in the case of the version 4.16.9.6 (partition layer). 
The splitting of the wall (4.16.9.7) has an inferior impact on the performance than expected. Obviously 
sound finds every way to come through. 
In the Fig. 102 the A-corrected sound levels for the bad variants together with the sound level of the 
original wall W2F-10 are presented. 
All also measures reduce the sound level in the higher frequency range but first from 3600 Hz upward. 
The most important common feature is that they start to increase the sound level above the level of the 
original wall below 3600 Hz. 
The heaviest supplementary contribution to the total sound level happens in the range of 0-2000 Hz. 
In the trial reported in section 4.16.9.8 the total mass of the walls was increased filling the hollow with 
granular material. From the enhancement of the mass by the factor 1,7 we expected a gain in relation to 
the original sound level of –2.3 dB.  
Looking at the spectrum of the 4.16.9.8 line, the decrease of the sound level above 2000 Hz is rather 
high but counterbalanced by the contribution in the low frequency range so that finally a worsening of 
the situation of 8.3 dB happened. 
This is obviously the result of the mass heightening. 
The feature of all the other “bad” variants shows the same behaviour. The question is now where the 
mass enhancement is coming from. 
Fig. 103 reveals the “secrete” nature of dry lining wall vibrations step by step.  
Applying the anti-drum tape to the external surface of the double-planked board as it is normally used 
in practice (see Fig. 93, 94) we obtain a good reduction of the sound level by –2.6 dB. 
Using  it  as  interlayer  between  the  two  boards  degrades  the  performance  above  that  of  the  untreated 
original wall by +1,7 dB. 
The  reason  is  not  that  the  tape  has  been  used  against  the  application  rules,  but  that  the  effective 
vibration mass of the double-planked board increases. 
The  interlayer  reduces  the  freedom  degree  of  vibration  of  the  single  boards  increasing  the  friction 
between them. 
The last increase is reached screwing the two panels together like it has been done in the trial version 
4.16.9.4. There another interlayer material was used, but this may be of secondary meaning. 
In this version we have one board of nearly double mass (first panel 12.5 mm, second panel 10.0mm 
thickness). 
In accordance with the role of mass increase worked out in Fig. 102 the sound level spectrum is shifted 
and enhanced toward lower frequencies.  
We  can  conclude  that  in  double-planked  walls  the  two  boards  screwed  together  only  along  the  edges 
vibrate individually outside  their physical spot constraints, the screws, clamping them together. 
If we look to the vibration amplitude measured during the different campaigns we can establish absolute 
values for the pipe side wall compared to that facing the microphones ranging from  1,5 µm to 0,5 µm. 
Therefore without every supplementary constraints the single boards have enough space between each 
other to vibrate free. 
The amplitude of the wall vibration is not responsible for the sound level value but it is the degree of 
freedom  necessary  to  develop  the  entity  responsible  for  the  sound,  the  velocity  of  the  panel 
displacement. 

4.16.10 First conclusions 

1. 

Because  a  free  house  design  cannot  live  with  only  one  good  solution  for  the  fitting  noise 
reduction (placement 3) further activities must be undertaken to improve the performance of the 
main basic wall with regard to further noise reduction.  

49 
 
 
 
2. 

3. 

4. 

5. 

6. 

7. 

A  silencer  has  been  defined  as  every  measure,  which  introduces  new  construction  elements, 
and/or  materials  in  the  basic  arrangement  to  the  greatest  possible  extend  according  to  the 
standard EN ISO 38221 used in the project.  

Primary silencers act on the feeding circuit to reduce the vibration energy of the pipe generated 
by the INS before it is introduced into the wall. Three different measures have been analysed. 
- 

Complete  jacketing  of  the  pipe  with  acoustic  foam  layer  of  density  120  kgm-3. 
Reduction of the sound level –4,8 dB 
Sound barrier B1, reduction of the sound level –1dB per barrier 
Sound barrier B1 embedded in agents with high internal friction, best result  -4,5 dB 

- 
- 

Secondary silencers modify the basic construction of the walls adding some new construction 
elements  (secondary  silencer  of  type  I)  or  layers  of  different  materials  (secondary  silencer  of 
type II) 

No secondary silencer of type I reached an improvement of the noise sound level reduction  

Secondary silencers of type II reached a best result of –10,6 dB (closed soft polyethylene foam, 
see section 4.16.9.6) 

The  trials  related  to  the  secondary  silencer  of  type  II  revealed  the  real  vibration  behaviour of 
light gauge walls, double planked. The inner board is screwed to the frame. The second or outer 
board is fastened along the edges to the first one also by screwing. 
The best performance is reached when the two boards are allowed to vibrate individually and a 
partition layer is introduced between the steel frame and the inner board. 

8. 

A  supplementary  effect  can  be  expected  using  the  measure  of  4.16.9.1  and  4.16.9.6  are  used 
together 

4.17  Real fittings, non-classified 

The  project  has  been  carried  out  based  on  the  normative  background  of  the  standard  EN  ISO  38221 
adapting it to the needs of dry lining work. 
The noise source required by the standard was mandatory to have a repeatability of the results in both 
labs. 
So working with the same noise source comparable results must be obtained. 
In addition improvements of the arrangements base on a transfer standard so that they are rather reliable 
under every experimental condition. 
It  remains  to  analyse  which  noise  is  produced  by  non-classified  commercial  fittings  and  which 
measures must be chosen to reach the targeted sound level of 30 dB. 
The  classification  of  fittings  distinguishes  between  class  1  (20  dB),  class  2  (20-30  dB)  and  non-
classified (> 30 dB). 
Two commercial fittings have been tested in connection with the test wall W2F, a ¾” (Fig. 104A) and a 
½” fitting  (Fig. 104B). The values of the total sound level are listed in table 35 for the unclamped and 
in table 36 for clamped case. For the valves two conditions have been tested, “normal” flow (18 l/min) 
and completely open (56, 48 l/min).  
The  standard  admits  a  range  of  water  pressure  up  to  0,5  MPa  and  a  flow  up  to  120  l/min.  Water 
installations in housings are designed for a flow of 15 l/min with a tendency to 12 l/min to reduce the 
sound level.  
Using the values of the tables a linear relation for the sound level in dependence on the flow has been 
established to obtain sound level values of 15 l/min as it is presented in Fig. 105. 
In any case the commercial ¾” fitting is unproblematic. Looking at the distribution of the sound level in 
dependence of the frequency, the values remain below those of the INS for a wide range of flow. Under 
the conditions of the maximal available flow the sound level value climbs up a little bit above that of 
the INS in the range of 0-2000 Hz.  
Nevertheless the frequency range between 1000-5000 Hz is the range in which humans have the highest 
sensitiveness for sound. 

50 
 
 
 
 
 
 
 
 
 
The ½” valve is surely the most common fitting in domestic and buildings applications.  
A non-classified ½” tap flow of 25 l/min should produce a sound level of about 36 dB. In comparison 
low noise fittings for 30 dB (group II) are flow limited at 15l/min to reach the sound level value. 
So it is reasonable to set the targeted reduction power of a measure to –6 dB (or higher if wanted) to 
realise a good relation between expenditure and benefit. 
The sound level spectra of a ¾” valve for the two tested flow values are revealed in Fig. 106. The main 
qualitative difference between the INS-spectrum and the tap spectrum results from the frequency range 
above 5000 Hz. 
At the highest flow value the sound spectrum lies totally above that of the INS, nearly parallel to it. 

The analogue spectra for a ½”-valve are given in the last Fig. 107. 
It  is  very  important  to  stress  the  relation  to  the  tested  reference  wall,  here  the  W2F,  because  with 
exception  of  the  test  wall  W4F-10  in  Table  14,  the  INS  generates  sound  level  values  with  the  other 
walls between +2,3 to +6,6 dB higher than that of the wall W2F. 
The  slightly  better  wall  (-0,8  dB),  the  double  planked  wall  with  split  C-profiles  is  a  special  wall  and 
falls therefore out of choice.  
Although the noise generation of non-classified cheap fittings is “open end” nobody would purchase a 
tap making tremendous noise at usual flows of 15 l/min. 

5. 

Final Conclusions 

The target of project was to develop solutions for the reduction of fitting noise based on the standard 
EN  ISO  38221  “Laboratory  tests  on  noise  emission  from  applications  and  equipment  used  in  water 
supply installation” using a standardized noise gauge. 
The standard uses a reference noise source called Installation Noise (Transfer) Standard (INS), which 
produces a calibrated equivalent total sound level of 46,8 dB.  
Every available commercial fitting generates a noise level, which is lower than that of the INS. So the 
fitting noise can be measured in relation to the sound level of the INS making the results independent 
from the specific features of the current measuring lab.   

1. 

2. 

3. 

The project used the Installation Noise Standard as the fitting whose noise level of 46,8 dB was 
to reduce to the limit of 30 dB prescribed by the legislator. 
Because the INS produces a reference sound level higher than that of any customary fitting, it is 
possible  to  keep  the  sound  propagation  in  light  gauge  walls  less  than  30  dB  for  every 
commercial fitting.  

The project dealt with different walls manufactured according to the standard 
DIN EN 14195  

Metal framing components for gypsum plasterboard systems 
Definition, requirements and test methods. 

Steel frames with slit C-profiles developed to improve the airborne reduction have been 

taken also in consideration. 
An earthquake version (Turkish norm) completed the wall set. 
The  greatest  part  of  the  work  was  focussed  on  the  main  consumer  board  materials,  gypsum 
board (GB) and gypsum fibreboard (GF). 
Gypsum  and  gypsum  fibreboard  show  a  comparable  performance  in  relation  to  fitting  noise 
reduction within the range of 1,2 dB. 
Although the static mechanical parameters of gypsum fibreboard are rather higher than that of 
gypsum board, the dynamic properties of both materials are comparable. 
OSB (Oriented-Strand-Board) as a niche product was used in some cases. 

(placement  1)  consisted 

The  basic  arrangement 
in  a  basic  main  wall  of  size 
LengthxHightxThickness = 3.75x2.50x0.12 m, single or double planked (GB or GF, or one side 
OSB, one side double planked GB or GF). 
The best and second-best result for the basic arrangement without further measures in relation 
to the reduction of fitting noise transport through the wall amounts to 

51 
 
 
 
 
 
  
 
 
 
 
 
 
 
 
 
4. 

5. 

6. 

7. 

8. 

- 
- 

-5.3 dB, wall, double planked (GB or GF), steel frame with slit C-profiles 
-4,5 dB, wall, double planked (GB or GF), conventional steel frame  

In any case all the double-planked versions show superior performances in comparison to the 
corresponding single-planked.   
As  the  further  investigations  showed,  in  a  double-planked  wall  every  board  vibrates 
individually having only the half of the vibration energy at its disposal, because it must be split 
up regularly between all the vibrating boards.  

The combination of OSB on one side and double-planked GB or GF on the opposite side using 
the conventional steel frame reaches a better airborne sound reduction than the specialists for 
airborne sound reduction, the walls with split C-profiles, namely absolute 28.8 dB compared to 
30.6 dB. The airborne sound level in the mounting room adjacent to the measurement room was 
60 dB. 
Although  solutions  for  airborne  reduction  were  not  a  subject  of  the  project,  such  side  effects 
contribute to make the product steel house more attractive.  

Wall  vibrations  generated  by  the  pipe  fastened  on  one  side  of  the  light  gauge  wall  are 
transmitted to the opposite side facing the measurement (microphone) room mainly by the top 
U-profile and only at 6,6% per C-profile face-to-face. 
Because the full weight of the wall stays on the bottom U-profile the vibration transport across 
the bottom web is negligible.  

The  more  complex  arrangements  consisting  of  the  basic  wall  and  a  secondary  wall  of  size 
LengthxHeightxThickness = 2.5x2.5x0.12 m, joined perpendicularly to the basic wall has been 
thoroughly analysed. Two groups of arrangements can be differentiated: 

- 

- 

The main basic  wall bears the feeding pipe and the vibrations are generated in the basic 
wall. This is the active wall. The secondary wall has the function to affect the vibration 
generation of the main wall by its hard connection to it. It is the passive wall (placement 
2). 
The secondary wall bears the feeding system being now the active wall and should put 
the passive main wall in vibration by its connection to it (placement 3).  

Three different connection options have been introduced. 

- 
- 

- 

Connection A: secondary wall screwed on a C-profile of the main wall “hard” 
Connection C:  secondary  wall  screwed  on  a  C-profile  of  the  main  wall  “soft”.  In  this 
case a layer of acoustic foam of 20 mm thickness has been intercalated between the two 
walls. 
Connection D: secondary wall screwed aside of any C-profile on the main wall, hard. 

Because of the conclusion number 5 the effect of a passive secondary wall should be negligible, 
so  that  the  sound  level  of  the  excited  basic  wall  must  be  comparable  to  that  of  conclusion  3 
(placement 2). 

Due  to  the  same  reason  an  active  secondary  wall  transmits  only  a  small  part  of  the  vibration 
energy to the passive main wall across its end C-profile (placement 3). 
Therefore the results of this second design must be the best of all. 
Best and second-best result: 

- 
- 

-16,6 dB, wall, double planked (GB or GF), conventional steel frame, connection C 
-15,1 dB wall one side double planked (GB or GF), other side OSB, conventional steel 
frame, connection C 

Nevertheless  all  the  different  walls  used  in  the  project  and  all  three  connections  reach  better 
results than all other placements. 

52 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
- 
- 
- 

Connection A: best result –14,1dB, worst result: -6,2 dB (see table 24) 
Connection C: best result –16,1dB, worst result: -13,2 dB (see table 26) 
Connection D: best result –14,9dB, worst result: -10,9 dB (see table 28) 

9. 

A  further  improvement  of  the  performance  of  the  basic  wall  (see  conclusion  3)  requires  the 
application of supplementary measures.  

Every  measure  suitable  to  reduce  the  sound  level  of  a  fitting,  which  is  not  a  construction 
element of the basic wall module, is called a silencer. 

The basic module or wall consists of  

- 

- 
- 

A steel frame of vertical C-profiles split or not and two horizontal U-profiles on which 
the C-profiles are fastened to produce a stiff skeleton, 
A layer of boards single or double on both sides of the skeleton,  
Acoustic or thermal mineral wool inside.  

10. 

A primary silencer is a measure suitable to reduce the fitting noise acting directly on the feeding 
system without changing anything in the wall. The sound level of the fitting itself is 
constructional and cannot be modified without destroying its initial identity.  
Primary silencer analysed are: 

- 

- 
- 

Complete jacketing of the feeding pipe with acoustic foam layer of density 120 kgm-3 
sound level reduction: -4.8 dB. 
Sound barrier B1, sound reduction per barrier: -1.0 dB.  
Sound barrier B1, embedded in material with high internal friction, best result: -4,6dB. 

The effect of the primary silencers adds to the performance of the basic wall, so that a basic 
wall with silencer can reach a total sound reduction of around –10.0 dB. 

Secondary silencers of type II concern measures modifying the characteristic of the light gauge 
wall by additional materials. Because secondary silencers of type I were not successful they are 
not  mentioned in the final conclusions. 
Best result: 

- 

-10.6 dB. Closed soft polyethylene foam layer between steel frame and board.  

Using the results of the project the sound level of an Installation Noise Standard of 46.8 dB can 
be downgraded in dependence of the wall design and further measures to 30 dB. The project 
results offer the possibility to reduce the input noise level down by –16,8 dB down to  –21.6 dB 
intercalating a primary silencer between fitting and the pipe. 

Non-classified customary fittings, the most common group, produce a sound level of 36 dB at a 
flow of 25 l/min, which is a rather reasonable maximal output in housings. 
Therefore the sound level of a customary non-classified source of 36 dB can be reduced to less 
than 20 dB, the sound level of low breathing. 

11. 

12. 

13. 

6. 

Exploitation and impact of the research results 

This  is  the  first  systematic  expertise  drawing  the  possibilities  of  noise  reduction  in  light  gauge 
constructions comparable to or better than that in stonewalls environments.  
Therefore their application can start first now. 
The addressees of the results are the firms working in dry lining business. These are the first to be able 
to use the technical and economic potential of the results.  

53 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
Generally they are small companies with low engineering potential who look for solutions in the local 
environment.  
So the most effective dissemination way of the results to the firms runs over the regional Chamber of 
Industry  and  Commerce  in  the  national  language  and  as  download  document  in  the  homepage  of  the 
contractors of the project. By now the Internet is the most frequented information source for everybody 
so it should be very probable that the results of the project reach their true users on this way.  
Therefore it is necessary to reproduce the guideline in the national language. 

54 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
4.1-Fig. 15  
Show steel house in Eisenhüttenstadt, Germany, constructed by FQZO, 2003 

4.1-Fig. 2  
Steel skeleton of the show house with the basic distance  612 mm 

5 The label contains the section number to which the figure belongs, followed by  “Fig.” and a control number 

55 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
                                                 
4.1-Fig. 3 

Light gauge wall assemblage of three modules 

4.4-Fig. 4 
Thermal insulation with thermal mineral wool (show house) 

56 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
2500 

1250 

4.5-Fig. 5 

Dry lining modules 

4.5-Fig. 6  
Combined light gauge wall assemblage 

57 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
4.5-Fig. 7 
Earth quake version (Turkish Norm) 

4.6-Fig. 8 
The features of fitting noise propagation 

58 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
S

WallM 

WallP

4.6-Fig. 9 
Oscillator model for the wall vibration transport 

4.7-Fig. 10 
A-Correction or weighting characteristics 

59 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
Pain Barrier 

Hearing Degradation 

Drop in Productivity 

Communication 
Disorder 

Normal Conversation 
50-60 dB

Learning and 
Concentration Disorder 

Whisper 
30 dB

Sleep Disorder 

Low Breathing
20-25 dB

20 dB

40 dB

60 dB

80 dB

100 dB  120 dB 

4.7-Fig. 11 
Detrimental impact of  continuous sound levels 

4.8-Fig. 12 
Sound lab FQZ 

60 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
4.8-Fig. 13 
Pressure vessel (in front) with pump and reservoir (behind) 

4.8-Fig. 14 
Completed sound room for fitting noise measurements, FQZO 

61 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
4.8-Fig. 15 
Installation Noise Standard Generator 

Sound Level Spectrum of the Installation Noise Standard in one-third Octave Steps

B
d
n

i

l
e
v
e
L
d
n
u
o
S

40

35

30

25

20

15

10

5

0

0

1000

2000

3000

4000

5000

6000

AFINOPRO-Abschlußbericht.xls

Ohne-third Octave in Hz

4.8-Fig. 16 
Sound Level Spectrum of the Installation Noise Standard in one-third Octave Steps 

62 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
4.9-Fig. 17 
Former power control building, red rectangle lab position FQZO 

(a) 

                (b) 

4.9-Fig. 18 
Acoustic lab ISQ 

63 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
4.9-Fig. 19 
Draft acoustic lab ISQ 

Installation Noise Standard (INS) 

13 kgm-2 
10 kgm-2 

25 kgm-2 
19  kgm-2 

 200 kgm-2 

4.10-Fig. 20 
Measurement of fitting noise according to EN ISO 3822-1 and to AFINOPRO 

64 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
0
5

7
8

CEILING 

Acoustic foam 

FLOOR 

Wood   

Acoustic foam 

OSB-stripe 

Phonewell 

4.11.1-Fig. 21 
Vibration insulation 

soundproofed
 test room

MP 2
H=1200
(MP 5)

MP 3
H=1400
(MP 7)

MP 1
H=1800
(MP 2)

m
6
,
2
x

5
8
,
3

l
l

a
w
g
n
i
r
u
s
a
e
m
e
r
u
t
r
e
p
a

4.11.2-Fig. 22 
Microphone positions in the measurement or microphone room 

65 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
          
External noise Sound Level FQZO/ISQ

FQZO

ISQ

B
d
n

i

l
e
v
e
L
d
n
u
o
S

50

45

40

35

30

25

20

15

10

5

0

10

100

1000

10000

AFINOPRO_Abschlußbericht.xls

Frequency in Hz

4.11.3-Fig. 23 
External Noise Level FQZO/ISQ 

Measuring 
plumbing 

Installation 
Noise Standard  

4

3

2

1

Measuring wall 

Measuring room 

Pipe clamps 

4.12.1-Fig. 24 
Measurement with placement 1 

4.12.1-Fig. 25 
Measuring wall during and after installation (installation room side) 

66 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
   
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 4.12.1- Fig. 26 
Measuring wall (measuring room side)  

4.12.1-Fig. 27 
Fastening details. Supplementary pipe fastening on a C-profile 

GF Sound level in dependence on the fastening technique, A-corrected

70

60

50

40

30

20

10

B
d
n

i

l
e
v
e
l

d
n
u
o
S

0

10

Two Sides
One Side

100

1000

10000

Abschlußbericht_überarbeitet.xls

Frequency in Hz

4.12.1-Fig. 28 
GF Sound level in dependence on the fastening technique, A-corrected 

67 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
  
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
Cross measurements Leq Gypsum board (GB)/Gypsum fibreboard (GF)

60

50

40

30

20

10

B
d
n

i

l

e
v
e
L
d
n
u
o
S

0

10

AFINOPRO Abschlußbericht.xls

100

1000

10000

One-third-octave centre frequency in Hz

4.12.3-Fig. 29   
Cross measurements Leq GB /GF 

Cross Measurements Leq Gypsum Board (GB)/Gypsum Fibreboard (GF), Noise-cleared

B
d
n

i

l

e
v
e
L
d
n
u
o
S

50,0

45,0

40,0

35,0

30,0

25,0

20,0

15,0

10,0

5,0

0,0

10

100

1000

10000

AFINOPRO Abschlußbericht.xls

One-third-octave centre frequency in Hz

4.12.3-Fig. 30  Cross Measurements Leq GB/GF, Noise-cleared 

Cross measurements Leq Gypsum Board (GB)/Gypsum Fibreboard (GF), Noise-cleared, A-corrected

B
d
n

i

l
e
v
e
L
d
n
u
o
S

45

40

35

30

25

20

15

10

5

0

GB-ISQ

GB-FQZO

GF-FQZO

GB-ISQ

GB-FQZO

GF-FQZO

GB-ISQ

GB-FQZO

GF-FQZO

10

100

1000

10000

AFINOPRO Abschlußbericht.xls

One-third-octave centre frequency in Hz

4.12.3-Fig. 31Cross measurements Leq GB/ GF, Noise-cleared, A-corrected 

68 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
4.12.5-Fig. 32 
Earthquake version Wall W-9F-10 (Turkish norm) 

L1
L1
93422
93422

90
90

62,5
62,5

L2
L2
93269
93269

65
65

L3
L3
93116
93116

110
110

L4
L4
92963
92963

125
125

260
260

385
385

4.13-Fig. 33 
Basic wall with basic pipe clamping positions 

69 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
INS 

4.13.1-Fig. 34 
Transmission and filtering of INS vibration generation 

(a ) 

(b ) 

4.13.2-Fig. 35 
Single modules (a) domestic application, (b) simulation conditions 

70 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
(a) 

(b) 

(a)  Hard fastened U,C-Profiles, (b) nearly free C-Profiles 

4.13.2-Fig. 36 

4.13.2-Fig. 37 
Load Case 1 

4.13.2-Fig. 38 
Load Case 2 

71 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
  
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
4.13.2-Fig. 39 
Load Case 2 

4.13.2-Fig. 40 
Load Case 2 

(a)- L oad C ase 1,2 

(b)- L oad C ase 2 

4.13.2-Fig. 41 
Vibration characteristics 

72 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
B

A

A’

4.13.2-Fig. 42 
Point or node connection 

(a) 

(b) 

4.13.2-Fig. 43 
Load case 3 

4.13.2-Fig. 44 
Load case 4 

73 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
4.13.2-Fig. 45 
Corner of the module with U (blue), C-beam, wall 1 and 2 

(a)                                                               (b) 
4.13.2-Fig. 46 
Selection of master & slave surfaces (Wall to U-beam) (a), tie created (b) 

74 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
4.13.2-Fig. 47 
Assembly 1250x2500 mm2, node tied 

4.13.2-Fig. 48 
Boundary conditions for the module 

75 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
(a)                                                                   (b) 
4.13.3-Fig. 49 First eigenfrequency at mx = my = 1, 10,743 Hz 

(a)                                                                (b) 
4.13.3-Fig. 50  Ninth eigenfrequency at mx = 2, my = 3 at 27,315 Hz 

4.13.4-Fig. 51 Assembly with contact ties (yellow) between C, U-profiles and panels 

76 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
4.13.4-Fig. 52 First mode at  =  5.71 Hz 

4.13.4-Fig. 53 Fifth mode at  =  13.25 Hz 

(a) 

(b) 

4.13.4-Fig. 54  Details of Fig. 53, fifth mode 

77 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
4.13.5-Fig. 55 
Measurement of perpendicular vibrations (x) of pipe and plate on the wall 

4.13.5-Fig. 56 
Measurement of longitudinal (y) and perpendicular vibration (x) of the wall 

Ro y 

Wa  x 

Wa y 

GeWa  x 

Se  z  

Se  z  

4.13.5-Fig. 57  
Co-ordinate system for vibration measurements 

78 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
Acceleration Spectra of Pipe(x) and Wall(x) Pipe Side , p = 3 bar, 0-10000 Hz

1,4

1,2

1

0,8

0,6

0,4

0,2

²
s
/
m
n

i

n
o
i
t
a
r
e
l
e
c
c
A

0

0

VM_Acc_3b_cl2.xls

0

-0,02

-0,04

-0,06

-0,08

-0,1

-0,12

Pipe(x)
WallP(x)

1000

2000

3000

4000

5000

6000

7000

8000

9000

10000

Frequency in Hz

4.13.5-Fig. 58  
Acceleration Spectra of Pipe(x) and Wall(x) Pipe Side , 0-10000 Hz 

4.13.6-Fig. 59 
Measurement of vibration transport by members 

79 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
U_t_f

U_t_w 

C_f 

C_w

U_b_f 

U_b_w 

4.13.6-Fig. 60 
Measurement positions for vibration measurements 

4.13.6-Fig. 61 
Uniform vibration by airborne sound (a) and bending vibration by spot excitation (b) 

(a) 

(b) 

80 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
Measuring wall 

Measuring room 

Measuring 
plumbing 

Installation 
Noise 
Standard 

4

3

2

1

4.14-Fig. 62 
Measurements with the placement 2  

A 

C 

D 

Panel   
joint spatula 
mineral wool   
elastic stripe 
drywall screw  

A’ 

4.14-Fig. 63 
Wall connections used in the project 

81 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
    
     
 
4.14.1-Fig. 64  
Placement 2, wall W-1F-2A, microphone room 

4.14.1-Fig. 65  
Placement 2, wall W-1F-2D, microphone room 

82 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
Pipe clamps 
2 
1 
4 

3 

Measuring wall 

Measuring room 

Installation 
Noise 
Standard 

Measuring 
plumbing 

4.15-Fig. 66 
Measurements with the placement 2  

4.15-Fig.67 
 Placement 3, wall W2F-3D, mounting room 

83 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
4.15-Fig. 68 Placement 3, wall W2F-3D, mounting room 

300 

660 

1260 

840  

450 

300   

200 

350

4.16.4-Fig. 69 
FEM Simulation of the experimental arrangement 

4.16.4-Fig. 70 
Transversal (x), Transversal (y), Thickness Modes  

84 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
   
Mode Structure

y

z

x

r
e
b
m
u
N
e
d
o
M
c

i
t
s

i
r
e
t
c
a
r
h
C

10

9

8

7

6

5

4

3

2

1

0

0

500

1000

1500

2000

2500

3000

3500

4000

Frequency in Hz

Direction of mode  Mode
X (transversal tr(x))
Y (transversal tr(y)) 
Z (longitudinal lg(z))
D (thickness) 
XD (thickness+tr(x))
YD (thickness+tr(y))
ZD (thickness+lg(z))
XZ (tr(x)+lg(z)) 
YZ (tr(y)+lg(z)) 

1 
2 
3 
4 
5 
6 
7 
8 
9 

4500

4.16.4-Fig. 71 
Vibration modes of the pipe of Fig. 69, inclusive table with mode type 

(a) 

(b) 

4.16.4-Fig. 72 

(a)  Mixed thickness+transversal(x) mode and (b) transversal(y) mode  

4.16.5-Fig. 73 Pipe (P0) 

4.16.5-Fig. 74 Barrier 1 (B1) 

85 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
P0 

B1 

B2 

B3 

B4 

4.16.5-Fig. 75  Sound barrier family  

4.16.5-Fig. 76 Barrier 3 (B3) 

4.16.5-Fig. 77 Barrier 4 (B4) 

Modal Analysis for P1 and P4 arrangements 

16000

14000

12000

10000

8000

6000

4000

2000

z
H
n

i

y
c
n
e
u
q
e
r
F

0

0

P0

+P1+P1

+P1 P1

+P1-P1

P4

20

40

60

80

100

120

Mode number

4.16.5-Fig. 78 
Modal analysis for different versions of B1 barriers to B4 barrier 

86 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
Amplitude A(y) at clamp CP1 of Pipe P0

Amplitude A(y) at CP1 and CP2 for Barriers B1, -B1

4

3,5

3

2,5

2

1,5

1

0,5

m
m
n

i
e
d
u
t
i
l

p
m
A

0

0

2000

4000

6000

8000

10000

12000

14000

16000

5

4,5

4

3,5

3

2,5

2

1,5

1

0,5

m
m
n

i

e
d
u
t
i
l

p
m
A

0

0

CP1
CP2

2000

4000

6000

8000

10000

12000

14000

Mode frequency in Hz

Frequency in Hz

4.16.5-Fig. 79 Spectral Amplitude (SA) pipe P0                   4.16.5- Fig. 80 (SA) according to Fig. 43 

Vibration Amplitude A(y) at the clamping CP1 and CP2 

Amplitude A(y) at CP1 for Barrier B4

6

5

4

3

2

1

m
m
n

i

e
d
u
t
i
l

p
m
A

0

0

CP1

CP2

4,5

4

3,5

3

2,5

2

1,5

1

0,5

m
m
n

i

e
d
u
t
i
l

p
m
A

0

0

2000

4000

6000

8000

10000

12000

14000

Mode Frequency in Hz

2000

4000

6000

8000

10000

12000

Frequency in Hz

4.16.5-Fig. 81 (SA) according to Fig 76                       4.16.5-Fig. 82  (SA) according to Fig. 46    

4.16.6-Fig. 83 Silencer with wall W-9F-10u (u for U-Silencer) 

87 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
4.16.6-Fig. 84 Silencer with supplementary damping 

A-corrected Sound Level Reduction by Silencer and Supplementary Damping

without Silencer

46

45

44

43

42

41

B
d
n

i

d
e
t
c
e
r
r
o
C
A

-

l
e
v
e
L
d
n
u
o
S

40

0

Auswertung_Spektren.xls

1

2

3

4

Bulk Density in kg/Litre

4.16.6-Fig. 85  
Sound level reduction by silencer and supplementary friction damping 

88 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
(a), (b) 

60

50

40

30

20

10

q
e
L

l
e
v
e
L
d
n
u
o
S

(c) 

4.16.7-Fig. 86  Variants of secondary silencer 

(d) 

Sound Level Leq without (0) and with different Secondary Silencer (a-d)

0
(a)
(b)
(c)
(d)

0

10

Auswertung_Spektren.xls

100

1000

10000

100000

Logarithmic Frequency in Hz

4.16.7-Fig. 87 
Sound level spectra of the silencer variants of Fig. 86 

89 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
(a) 

(b) 

(c) 

4.16.8-Fig. 88  First, second and third room modes 

MP 3

MP 2

MP 1

MP 6

MP 5

MP 4

MP 9

MP 8

MP 7

4.16.8-Fig. 89  Microphone positions in the mounting room 

Equivalent sound level, mounting room microphone positions 1-9

MP1
MP2
MP3
MP4
MP5
MP6
MP7
MP8
MP9

70

60

50

40

30

20

10

B
d
n

i

l
e
v
e
l

d
n
u
o
s
t
n
e
l
a
v
i
u
q
E

0

10

W2F_40_MP1_3_Montageraum.xls

100

1000

10000

Frequency in Hz

4.16.8-Fig. 90 
Sound level in the mounting room at all microphone positions 

90 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
Equivalent sound level of the airborne sound in the measurement room, wall W2F_40 

60

50

40

30

20

10

B
d
n

i

l
e
v
e
l

d
n
u
o
s
t
n
e
l
a
v
i
u
q
E

0

10

W2F_40_MP1_OS_3.xls

100

1000

10000

Frequency in Hz

4.16.8-Fig. 91 
Airborne sound level in the microphone room coming from the mounting room 

4.16.8-Fig. 92 
Pressure distribution at 0.0275s after the sound source started 

91 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
4.16.9.1-Fig. 93 
Wall with anti drum tape inside (section 4.16.9.1) 

4.16.9.1-Fig. 94  
Anti drum tape, draft (section 4.16.9.1) 

Anti drum tape between the panels, draft (section 4.16.9.2) 

4.16.9.2-Fig. 95  

92 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
  
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
(a) 

(b) 

4.16.9.3-Fig. 96 
Inner layer for impact sound (a) between the panels, (b) wall closed (section 4.16.9.3) 

4.16.9.4-Fig. 97 
Screws draft for each single module (section 4.16.9.4) 

(a) 

(b) 

4.16.9.5-Fig. 98 
Inner layer of acoustic foam (a) between the panels, (b) wall closed (section 4.16.9.5) 

93 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
(a) 

(b) 

4.16.9.6-Fig. 99 
Partition layer between members and boards (section 4.16.9.6) 

4.16.9.7-Fig. 100 
Split boards in the mounting room (section 4.16.9.7) 

4.16.9.9-Fig. 101 A-corrected sound level for the best wall variants of section 4.16.9 

94 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
4.16.9.9-Fig. 102 A-corrected sound level for the bad wall variants of section 4.16.9 

4.16.9.9-Fig. 103 A-corrected sound level for the wall variants 4. 16.9.1, 4.16.9.2, 4.16.9.4 

A 

B 

4.17-Fig. 104    
¾"-valve (A), ½”(B) , not classified 

95 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
A-corrected sound level  at 3 bar in dependence of the water flow for tap A , B
 non-classified, clamped

y = 0,4167x + 27,1

y = 0,3105x + 22,811

A

B

20

30

40

50

60

55

50

45

40

35

30

25

10

B
d
n

i

l

e
v
e

l

d
n
u
o
S

AFINOPRO_Abschlußbericht.xls

Water flow in l/min

4.17-Fig. 105  A-corrected sound level  at 3 bar in dependence of the water flow for tap A , B 
 not-classified, clamped 

A-corrected Sound level of a 3/4" (A) valve for flow = 18, 56 l/min 

40

30

20

10

B
d
n

i

l
e
v
e
l

d
n
u
o
S

INS
18 l/min
56 l/min

0

0

AFINOPRO_Abschlußbericht.xl

2000

4000

6000

8000

10000

12000

14000

Frequency in Hz

4.17-Fig. 106  A-corrected Sound level of a ¾” (A) valve for flow = 18, 56 l/min 

A-corrected Sound level of a 1/2" (A) valve for flow = 18, 48 l/min 

40

30

20

10

B
d
n

i

l
e
v
e
l

d
n
u
o
S

INS
18 l/min
48 l/min

0

0

AFINOPRO_Abschlußbericht.xls

2000

4000

6000

8000

10000

12000

14000

Frequency in Hz

4.17-Fig. 107    A-corrected Sound level of a ½” (B) valve for flow = 18, 48 l/min 

96 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
  Profile  

  Profile 
  Total 
  460 
  318 
  122 

  C 50-0,6 
  C100-0,6 
  C100-1,5 
  U101-2500    40 
  U103-2500    18 
  U111-2500    36 
  U101-3750    62 
  U103-3750    22 
  U111-3750    36 
  Special 1 
  Special 2 
  Special 3 
  Total 

  288 
  576 
  36 
  2014 

  Length 
  [m] 

2,5 
2,5 
2 ,5 
2,5 
2,5 
2,5 
3,75 
3,75 
3,75 
2,3 
2,3 
2,795 

  [m] 

  Thickness    Total Length 
  [mm] 
0,6 
0,6 
1,5 
0,6 
1,5 
0,6 
0,6 
1,5 
0,6 
0,6 
1,5 
1,5 

1150 
795 
305 
100 
45 
90 
233 
83 
135 
662 
1325 
101 
5023 m 

4.2-Table 16 
Member specification 

1 Panel 
Height [m] 
Width [m] 
Thickness [mm] 
Weight in kg/m² 
Gross Density [kg/m³]  
Young Modulus [N/mm²] Exx 
Young Modulus [N/mm²] Eyy 
Young Modulus [N/mm²] Exy 
Area in m² 
Weight/panel in kg 
1 Wall (/6 Panels) 
Single planking Weight in kg 
Twice planking Weight in kg 
Mineral wool (thickness 88 mm) 
Weight  kg/m² 
Weight per wall in kg 

Weight Steel Profiles/Wall in kg 

Wall complete, Weight in kg 
single planking 
twice planking 
Effective Wall density in kg/m² 
single planking 
twice planking 

Gypsum fibre 
2,50 
1,25 
12,5 
12,5 
115050 
3800 
3800 
3800 
3,125 
39,1 

Gypsum 
2,50 
1,25 
12,5 
9,5 
 680 
2800 
2200 
2300 
3,125 
29,7 

234 
469 

10,8 
101 
40,0 

376 
610 

40,1 
65,1 

178 
356 

10,8 
101 
40,0 

319 
497 

34,1 
53,1 

4.3-Table 2 
Boards Properties 

6  The label contains the section number to which the table belongs, followed by  “Table.” and a control number 

97 
  
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
                                                 
  
 
 
 
 
 
  
  
  
  
  
  
  
  
 
  
  
  
  
  
Gypsum Board 
Gypsum Fibreboard 
OSB 
Steel 

 
kg/m³ 

680 
1150 
640 
7897 

Exx 

Eyy 

Ezz 

xy 

Gxy 

Gxz 

[Nmm-2] 
2800 
3800 
3500 
210000 

[Nmm-2] 
2200 
3800 
1400 
210000 

[Nmm-2] 
2500 
3800 

210000 

[Nmm-2] 
1000 
1600 

[Nmm-2] 
1000 
1600 

80700 

80700 

0,15 
0,15 
0,34 
0,30 

4.3-Table 3 
Mechanical Properties of Wall Planking/Steel Details 

1/3 Octave 
Frequency 
[Hz] 
100 
125 
160 
200 
250 
315 
400 
500 
630 
800 
1000 
1250 
1600 
2000 
2500 
3150 
4000 
5000 
LAeq 

A-Sound 
Level 
[dB] 
28,0 
30,0 
31,8 
33,0 
34,0 
35,4 
36,6 
37,5 
37,5 
37,5 
37,5 
36,6 
34,6 
32,0 
27,4 
23,2 
19,0 
14,4 
46.8 

4.8-Table 4 
A-corrected reference sound level of the INS according to EN-ISO-3822-1, LAeq = 46.8 dB 

Parameter 
LAeq 
LAeq 
Leq 
Leq 
LAeq max 
LAeq min 
Leq max 
Leq min 

MP 1 
[dB] 
16,5 
14,2 
49,8 
17,0 
17 
16,1 
56,2 
41,7 

MP 2 
[dB] 
16,5 
14,3 
52 
18,6 
16,9 
16,2 
56,8 
44,4 

MP 3 
[dB] 
16,6 
14,2 
50,1 
16,8 
17,1 
16,3 
58,5 
43 

Average 
[dB] 
16,5 
14,3 
50,3 
17,5 
17,0 
16,2 
57,2 
43,0 

4.11.3-Table 5 
Mean of A-weighted and unweighted external noise level FQZO-lab 
Light green: frequency range 100-5000Hz.Others: 16-12500 Hz 

98 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 Parameter  Mic 1 
[dB] 
22,0 
21,1 
42,5 
41,6 
28,4 
20,6 
42,6 
0,0 

LAeq 
LAeq 
Leq 
Leq 
LAeq_max 
LAeq_min 
Leq_max 
Leq_min 

Mic 2 
[dB] 
22,7 
20,7 
54,0 
40,4 
25,0 
21,6 
49,5 
0,0 

Mic 3 
[dB] 
23,4 
21,6 
53,1 
42,0 
24,8 
22,5 
48,6 
0,7 

Average 
[dB] 
22,7 
21,1 
53,5* 
41,2 
24,9* 
21,6 
49,1* 
0,2 

4.11.3-Table 6 
Mean of A-weighted and unweighted external noise level ISQ-lab 
Light green: frequency range 100-5000Hz 
Others: 16-12500 Hz 

* only average of Mic 2 and Mic 3 according to EN ISO 3822-1 

Parameter  MP 1 
[dB] 
63,3 
63,4 
64,3 
62,5 
64,6 
62,6 

LAeq 
LLeq 
LAeq_max 
LAeq_min 
Leq_max 
Leq_min 

MP 2 
[dB] 
63,3 
63,6 
64,3 
62,5 
64,5 
62,8 

MP 3 
[dB] 
63,2 
63,8 
63,9 
62,6 
65,1 
63 

Average 
[dB] 
63,3 
63,6 
64,2 
62,5 
64,7 
62,8 

4.12.2-Table 7 
Gypsum fibreboard; A-weighted and unweighted sound level  
of INS at 3 bars, clamps fastening according to EN ISO 3822-1 

Parameter 

LAeq 
Leq 
LAeq_max 
LAeq_min 
Leq_max 
Leq_min 

MP 1 
[dB] 
46,7 
56,9 
47,8 
45,6 
65,1 
52,3 

MP 2 
[dB] 
46,7 
57,7 
47,8 
45,9 
66,5 
52,5 

MP 3 
[dB] 
47,0 
58,0 
48,0 
46,2 
65,3 
52,2 

Average 
[dB] 
46,8 
57,5 
47,9 
45,9 
65,6 
52,3 

4.12.2-Table 8 
Gypsum fibreboard; A-weighted and unweighted sound level  
of INS at 3 bars, clamps fastening only on pipe side wall 

99 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
Parameter 
LAeq 
LAeq+noise cleared 
Leq 
LAmax 
LAmin 
LLmax 
LLmin 

MP 1 
[dB] 
47,9 
46,1 
55,6 
49,3 
46,8 
59,6 
52,8 

MP 2 
[dB] 
48,4 
46,7 
56,8 
49,7 
47,3 
61,7 
53,2 

MP 3 
[dB] 
47,8 
45,8 
56,3 
48,5 
47,0 
60,2 
53,1 

Average 
[dB] 
48,0 
46,1 
56,2 
49,2 
47,0 
60,5 
53,0 

4.12.3-Table 9 
FQZO-Measurement W1G-11 Single wall (gypsum) 
A-weighted and unweighted sound level LCS of INS at 3 bars, clamped  

Yellow line: sound level  A-corrected+noise cleared 

Parameter 
LAeq 
LAeq+noise cleared 
Leq 
LAmax 
LAmin 
LLmax 
LLmin 

MP 1 
[dB] 
35,3 
23,2 
55,6 
36,5 
34,2 
54,6 
6,8 

MP 2 
[dB] 
34,4 
26,2 
58,4 
36,3 
33,1 
52,5 
6,6 

MP 3 
[dB] 
34,4 
25,3 
56,0 
35,2 
33,5 
50,5 
7,3 

Average 
[dB] 
34,7 
24,8 
56,6 
36,0 
33,6 
52,5 
6,9 

4.12.3-Table 10 
ISQ-Measurement W1G-1_0 Single wall (gypsum) 
A-weighted and unweighted sound level LCS of INS at 3 bars, clamped  

Yellow line: sound level A-corrected +noise cleared 

FQZO  Gypsum board 

unclamped 

LAeq (3 bar) 
Leq (3 bar) 

37,6 
52,6 

Gypsum fibreboard 

clamped 
on C 
48,6 
56,9 

clamped 
12 cm aside C
48,0 
56,2 

unclamped

36,5 
55,3 

clamped 
on C 
48,8 
57,1 

clamped 
12 cm aside C
46,8 
57,5 

4.12.4-Table 11 
Sound level Leq and LAeq for gypsum board and gypsum fibreboard, FQZO measurements  

100 
 
 
 
 
 
 
 
 
 
  
 
 
 
 
 
 
 
 
 
 
 
 
 
Parameter 
LAeq 
Leq 
LAmax 
LAmin 
Lmax 
Lmin 

[dB] 
36,5 
55,3 
37,7 
35,3 
61 
48 

W1F-11  W2F-10  W3F-10  W4F-10  W5F-10  W6F-10  W9F-10 
[dB] 
[dB] 
30,6 
31 
52,5 
51 
31,6 
32,2 
29,8 
30,1 
58,8 
55,6 
44,3 
45,6 
4.12.5-Table 12 
Placement 1 : Sound level of the different walls, pipe free floating (airborne sound) 

[dB] 
33,8 
51,6 
35 
32,8 
57,6 
45,5 

[dB] 
30,2 
54,5 
31,2 
29,3 
60,6 
47,4 

[dB] 
28,8 
55,5 
29,8 
28 
64,2 
47,5 

[dB] 
31,1 
60,2 
32,3 
30,1 
66,7 
51,1 

Parameter 
LAeq 
INS 46,8 dB 
Leq 
Lmax 
LAmin 
Lmax 
Lmin 

W1F-11  W2F-10  W3F-10  W4F-10  W5F-10  W6F-10  W9F-10 
[dB] 
41,5 
-5,3 
54,6 
43,2 
40,4 
59,6 
48,9 

[dB] 
44,6 
-2,2 
54,7 
45,7 
43,7 
58,5 
51,4 

[dB] 
47,3 
0,5 
58,3 
48,5 
46,2 
63,2 
54 

[dB] 
42,3 
-4,5 
53 
43,6 
41,3 
58,1 
48,3 

[dB] 
46,8 
0 
57,5 
47,9 
45,9 
65,6 
52,3 

[dB] 
48,9 
2,1 
58,7 
50 
47,8 
65 
54,9 

[dB] 
44,7 
-2,1 
71,7 
44,8 
42,6 
78,3 
56,6 

        4.12.5-Table 13 

Placement 1: Sound level of the different walls, pipe clamped   

      Yellow line: difference between first line and INS sound level

Mode 
Number 
Index 
1 
2 
3 
4 
5 
6 
7 
8 
9 
10 
11 
12 
13 
14 

15 
16 
17 
18 
 

Mode 
Number (x) 

Mode 
Number (y) 

1 
2 
3 
1 
2 
4 
3 
5 
4 
1 
2 
6 
5 
3 

4 
6 
7 
5 

1 
1 
1 
2 
2 
1 
2 
1 
2 
3 
3 
1 
2 
3 

3 
2 
1 
3 

WallM(x) 
Measured 
[Hz] 
9,38 
15,63 
21,87 
26,56 
29,68 
37,53 
40,61 
50,00 
53,13 

65,62 

Mode 
Frequency 
[Hz] 
8,3 
13,3 
21,7 
28,3 
33,3 
33,3 
41,7 
48,4 
53,4 
61,7 
66,7 
66,7 
68,4 
75,0 

86,7 
86,7 
88,4 
101,7 

WallP(x,y) 
Measured 
[Hz] 

15,60 

26,56 
29,68 
35,93 
42,18 
50,00 
53,15 
57,81 
65,62 

70,31 
73,40 

79,64 
85,90 
90,63 
95,31 

(fcalc-fmeas)2 
WallP(x,y) 

(fcalc-fmeas)2
WallM(x,y) 

5,290 

3,028 
13,104 
6,917 
0,230 
2,560 
0,062 
15,113 
1,166 

3,658 
2,560 

49,844 
0,640 
4,951 
40,800 
3,0 

1,166 
5,441 
0,029 
3,028 
13,104 
17,851 
1,183 
2,560 
0,076 

1,166 

2,13 

4.12.5-Table 14 
Calculated and measured modes for a module 2,50 x 1,25m 
Light green : matching within  2 Hz, green :  1 Hz 

101 
 
  
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
  
Mode 
Number 
Index 
1 
2 
3 
4 
5 
6 
7 
8 
9 
10 
11 
12 
13 
14 
15 
17 
18 
20 
21 
22 
23 
24 
25 
28 
29 
30 
31 
32 
37 
38 
40 
41 
42 
43 
44 
45 
46 
47 
48 
49 
50 
51 
52 
56 
57 
58 
59 
60 
61 
 

Mode 
Number (x) 

Mode 
Number (y) 

1 
1 
2 
1 
2 
2 
1 
3 
3 
2 
1 
3 
2 
3 
4 
4 
2 
3 
1 
4 
3 
5 
2 
5 
1 
3 
4 
5 
3 
4 
2 
6 
5 
6 
4 
3 
1 
5 
6 
2 
7 
7 
4 
5 
1 
7 
2 
6 
7 

1 
2 
1 
3 
2 
3 
4 
1 
2 
4 
5 
3 
5 
4 
1 
2 
6 
5 
7 
4 
6 
1 
7 
3 
8 
7 
6 
4 
8 
7 
9 
3 
6 
4 
8 
9 
10 
7 
5 
10 
1 
2 
9 
8 
11 
4 
11 
7 
5 

Mode 
Frequency 
[Hz] 
2,4 
4,6 
7,4 
8,3 
9,6 
13,3 
13,5 
15,7 
18,0 
18,5 
20,2 
21,7 
25,2 
26,9 
27,4 
29,6 
33,3 
33,5 
38,0 
38,5 
41,7 
42,4 
43,0 
48,4 
49,1 
51,3 
53,4 
53,5 
62,4 
63,0 
66,7 
66,7 
68,4 
71,9 
74,1 
75,0 
75,8 
78,0 
78,6 
80,8 
82,4 
84,7 
86,7 
89,1 
91,3 
93,6 
96,3 
96,3 
100,2 

WallP(x,y) 
Measured 
[Hz] 

WallM(x) 
Measured 
[Hz] 

(fcalc-fmeas)2 
WallP(x,y) 

(fcalc-fmeas)2
WallM(x,y) 

9,38 

0,0506 

15,63 

15,63 

0,0056 

0,0056 

18,75 

21,88 

0,0625 

0,0306 

26,56 

26,56 

0,1156 

0,1156 

29,68 

0,0064 

32,83 

0,2256 

37,53 

35,93 

0,2256 

4,2849 

40,61 

43,75 

42,18 

1,1827 

0,5625 

0,0484 

50,00 

50,00 

0,8100 

0,8100 

53,13 

53,13 

0,0756 

0,0756 

62,50 

0,0100 

65,63 

65,62 

1,1556 

1,1664 

68,75 
71,87 

76,56 

73,44 

0,1225 
0,0008 

0,5776 

0,4389 

79,64 

1,0894 

82,82 

0,1722 

85,93 

85,93 

0,5910 

0,5910 

90,63 

90,63 

0,4556 

0,4556 

96,88 

95,31 

0,3306 

0,9752 

100,0 

0,65 

0,0400 
0,80 

4.12.5-Table 15 
Calculated and measured modes for a wall 2,50 x 3,75 m 
Light green : matching within  2 Hz, green :  1 Hz 

102 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
C-f 
flange 
0,263 

C-w 
web 
0,066 

U_t_f 
top flange 
0,056 

U_t_w 
top web 
1 

U_b_f 
bottom flange
0,013 

U_b_w 
bottom web 
0,006 

4.13.6-Table 16 
Relative vibration energy of members 

Parameter 
LAeq 
Leq 
LAmax 
LAmin 
Lmax 
Lmin 

W1F-2A 
[dB] 
36,3 
67,4 
35,3 
33,5 
60,6 
48,9 

  W2F-2A 

[dB] 
33,3 
54 
34,3 
32,4 
60,8 
47,7 

 W3F-2A 
[dB] 
32,8 
52,7 
33,8 
31,9 
58 
46,4 

  W4F-2A 

[dB] 
31,7 
54,2 
32,7 
30,7 
59,6 
47,2 

 W5F-2A 
[dB] 
30,9 
53,8 
31,9 
30,1 
59,5 
47,5 

 W9F-2A 
[dB] 
33 
55,5 
34,0 
32,1 
61,7 
48,7 

4.14.1-Table 17 
Placement 2, Wall connection A : Sound level, pipe free floating (airborne sound) 

Parameter 
LAeq 
INS 46,8 dB 
Leq 
LAmax 
LAmin 
LLmax 
LLmin 

W1F-2A 
[dB] 
48,5 
1,7 
56,2 
49,2 
47,8 
61,9 
52,7 

  W2F-2A 

[dB] 
45,2 
-1,6 
57,1 
46,8 
44 
62,7 
52,8 

 W3F-2A 
[dB] 
46,3 
-0,5 
57,4 
47,3 
45,3 
62,1 
53,4 

  W4F-2A 

[dB] 
42,9 
-3,9 
54,8 
44,1 
41,8 
59 
50,3 

 W5F-2A 
[dB] 
50,3 
3,5 
58,9 
51,8 
49,2 
62,7 
55,5 

 W9F-2A 
[dB] 
45,5 
-1,3 
58,4 
47,4 
44,2 
62,9 
54,3 

4.14.1-Table 18 
Placement 2, Wall connection A: Sound level, pipe clamped7  

W1F-2C  W2F-2C  W3F-2C  W4F-2C  W5F-2C  W9F-2C 

Parameter 
LAeq 
Leq 
LAmax 
LAmin 
Lmax 
Lmin 

[dB] 
34,6 
54,6 
35,7 
33,7 
60,5 
48 

[dB] 
33,9 
52,7 
35 
32,9 
58,6 
47,1 

[dB] 
32,9 
54,1 
34 
31,9 
59,8 
48,6 

[dB] 
31,7 
54,9 
32,7 
30,8 
60,9 
48,1 

[dB] 
30,4 
55,5 
31,2 
29,6 
62,3 
47,5 

[dB] 
- 
- 
- 
- 
- 
- 

4.14.1-Table 19 
Placement 2, Wall connection C : Sound level, pipe free floating (airborne sound) 

7      Yellow line: difference between first line and INS sound 

103 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
                                                 
W1F-2C  W2F-2C  W3F-2C  W4F-2C  W5F-2C  W9F-2C 

Parameter 
LAeq 
INS 46,8 dB 
Leq 
LAmax 
LAmin 
LLmax 
LLmin 

[dB] 
62,3 
15,5 
63,3 
63,1 
61,6 
65,5 
62,1 

[dB] 
44,3 
-2,5 
55,3 
45,6 
43,5 
60,4 
51,2 

[dB] 
44,7 
-2,1 
56,7 
46 
43,8 
61,1 
52,2 

[dB] 
42,1 
-4,7 
55,5 
43,3 
40,9 
59,8 
50,5 

[dB] 
49 
2,2 
57,8 
50,1 
48,2 
61,3 
54,5 

[dB] 
- 

- 
- 
- 
- 
- 

4.14.1-Table 20 
Placement 2, Wall connection C: Sound level, pipe clamped7 

Parameter 
LAeq 
LLeq 
LAmax 
LAmin 
Lmax 
Lmin 

W1F-2D  W2F-2D  W3F-2D 
[dB] 
[dB] 
33,9 
- 
53,3 
- 
34,9 
- 
32,8 
- 
60 
- 
46,4 
- 

[dB] 
34,9 
53,8 
35,9 
33,9 
60,6 
47,7 

W4F-2D  W5F-2D  W9F-2D 
[dB] 
31 
55 
32 
30,2 
61 
47,2 

[dB] 
33,4 
53,6 
34,4 
32,4 
60,9 
46,6 

[dB] 
32 
53,4 
32,9 
31,1 
59,5 
46 

4.14.1-Table 21 
Placement 2, Wall connection D : Sound level, pipe free floating (airborne sound) 

Parameter 
LAeq 
INS 46,8 dB 
Leq 
LAmax 
LAmin 
Lmax 
Lmin 

W1F-2D  W2F-2D  W3F-2D 
[dB] 
[dB] 
- 
45,5 
-1,3 
57,1 
47,3 
44 
61,1 
53,3 

[dB] 
63,2 
16,4 
63,8 
64,1 
62,5 
65,2 
62,7 

- 
- 
- 
- 
- 

W4F-2D  W5F-2D  W9F-2D 
[dB] 
50,8 
4 
59,6 
52,2 
49,7 
63,1 
56,5 

[dB] 
45,7 
-1,1 
57,7 
47,4 
44,4 
61,7 
53,9 

[dB] 
42,4 
-4,4 
54,4 
43,8 
41,3 
59,1 
49,7 

4.14.1-Table 22 
Placement 2, Wall connection D: Sound level, pipe clamped2 

104 
 
 
  
 
 
 
 
 
 
 
 
  
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
Parameter 
LAeq 
Leq 
LAmax 
LAmin 
Lmax 
Lmin 

W1F-3A 
[dB] 
32 
55 
33 
31,2 
60,1 
48,2 

W2F – 3A  W3F – 3A  W4F – 3A 
[dB] 
34,9 
54,4 
35,8 
34 
61,8 
46 

[dB] 
33,9 
54,2 
35,2 
32,8 
60,6 
47,5 

[dB] 
32,4 
54,9 
33,6 
31,4 
60,5 
48,3 

W5F-3A 
[dB] 
30,5 
53,4 
31,8 
29,5 
59,1 
45,8 

4.15.1-Table 23 
Placement 3, Wall connection A : Sound level, pipe free floating (airborne sound) 

Parameter 
LAeq 
INS 46,8 dB 
Leq 
LAmax 
LAmin 
Lmax 
Lmin 

W1F-3A 
[dB] 
40,6 
-6,2 
54,1 
42,4 
39,4 
59,1 
47,8 

W2F – 3A  W3F – 3A  W4F – 3A 
[dB] 
38,6 
-8,2 
55,4 
39,3 
37,6 
62,2 
47,9 

[dB] 
35 
-11,8 
53,7 
36,3 
33,8 
58,8 
47,6 

[dB] 
32,7 
-14,1 
56,1 
33,6 
31,8 
62,4 
48,4 

W5F-3A 
[dB] 
38,7 
-8,1 
53,9 
39,9 
37,7 
59,5 
47,4 

4.15.1-Table 24 Placement 3, Wall connection A: Sound level, pipe clamped7 

W1F - 3C  W2F – 3C  W3F – 3C  W4F – 3C 

Parameter 
LAeq 
LLeq 
LAmax 
LAmin 
LLmax 
LLmin 

[dB] 
32 
56,2 
32,9 
31,1 
63 
49,1 

[dB] 
30,3 
53,2 
31,4 
29,3 
58,7 
47 

[dB] 
32,7 
52,8 
33,7 
31,6 
59,2 
44,9 

[dB] 
33,3 
54,8 
34,4 
32,2 
64,1 
46,7 

W5F-3C 
[dB] 
31 
53,9 
31,9 
30,1 
60,1 
47,6 

4.15.1-Table 25 
Placement 3, Wall connection C: Sound level, pipe free floating (airborne sound) 

W1F - 3C  W2F – 3C  W3F – 3C  W4F – 3C 

Parameter 
LAeq 
INS 46,8 dB 
Leq 
LAmax 
LAmin 
Lmax 
Lmin 

[dB] 
32,7 
-14,1 
56,1 
33,6 
31,8 
62,4 
48,4 

[dB] 
30,2 
-16,6 
55,5 
31,2 
29,1 
63,6 
47,9 

[dB] 
33 
-13,8 
54,8 
34,1 
31,8 
61,6 
47,5 

[dB] 
33,1 
-13,7 
54,1 
34,3 
31,9 
60,5 
47,4 

W5F-3C 
[dB] 
31,7 
-15,1 
53,6 
32,5 
30,9 
60,1 
46,5 

4.15.1-Table 26 
Placement 3, Wall connection C: Sound level, pipe clamped7 

105 
 
  
 
 
  
 
 
 
 
 
  
 
 
  
 
Parameter 
LAeq 
LLeq 
LAmax 
LAmin 
Lmax 
Lmin 

W1F – 3D  W2F – 3D  W3F – 3D  W4F – 3D 

[dB] 
29,5 
57,6 
30,7 
28,5 
63,9 
49,3 

[dB] 
31,4 
53,6 
32,5 
30,3 
59,2 
47,1 

[dB] 
33,1 
55,9 
34,2 
32,1 
62,1 
48,3 

[dB] 
31,3 
54,7 
32,3 
30,3 
60,7 
47 

W5F-3D 
[dB] 
29,1 
53,7 
30 
28,2 
59,6 
47 

4.15.1-Table 27 
Placement 3, Wall connection D : Sound level, pipe free floating (airborne sound) 

W1F – 3D  W2F – 3D  W3F – 3D   W4F – 3D 

Parameter 
LAeq 
INS 46,8 dB 
Leq 
LAmax 
LAmin 
Lmax 
Lmin 

[dB] 
35,9 
-10,9 
56,4 
37,1 
34,9 
61,8 
50 

[dB] 
33,3 
-13,5 
53,3 
34,6 
32,2 
58,8 
46,8 

[dB] 
35,3 
-11,5 
57 
36,7 
34,3 
63,5 
49,7 

[dB] 
31,9 
-14,9 
56,2 
32,9 
30,9 
62,7 
48,4 

4.15.1-Table 28  
Placement 3, Wall connection D : Sound level, pipe clamped7 

W1F-3  W2F – 3  W3F – 3  W4F – 3  W5F-3 
[dB] 

[dB] 

[dB] 

[dB] 

[dB] 

W5F-3D 
[dB] 
34,7 
-12,1 
54,2 
35,9 
33,8 
60,3 
46,5 

A,C,D 

A 

8,6 

0,3 

3,7 

1,1 

8,2 

C 

D 

0,7 

-0,1 

0,3 

-0,2 

0,7 

6,4 

1,9 

2,2 

0,6 

5,6 

4.15.1-Table 29 
Vibration sound level transported by the connections A,C,D, i.e. difference between 
the fitting noise and airborne sound level 

106 
 
  
 
 
 
 
 
 
  
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
no 
36,5 

partial 
33,5 

W1F_11_3n  W1F_13_3 W1F_11_3n W1F_13_3 W1F_13_3n 
L-total 
L-airborne  L-airborne
no 
46,8 
0 
57,5 
47,9 
45,9 
65,6 
52,3 

L-total 
complete 
42,0 
-4,8 
55,0 
43,1 
41,0 
59,4 
50,5 

L-total 
partial 
45,3 
-1,5 
54,4 
46,1 
44,5 
59,4 
50,5 

55,3 
37,7 
35,3 
61 
48 

55,2 
34,7 
32,4 
61,8 
48,5 

Jacket 

Leq  [dB] 
INS 46,8 dB  
Leq  [dB] 
LAmax  [dB] 
LAmin  [dB] 
Lmax  [dB] 
Lmin  [dB] 

4.16.2-Table 30 
Sound level reduction by jacketing the pipe with acoustic foam7 
partial : jacketing of  the pipe along the lab envelope only 
complete : jacketing of the complete pipe inclusive along the test wall 

Material 

Silencer  Bulk Density
[kg/Litre] 

Granularity
[mm] 

B1 

Slate Chamotte 

no 
yes 
yes 
Corundum ALODUR  yes 
yes 
Granular Hard Cast 
no 
Soft Coupling INS 

0 
0 
1,46 
2,18 
3,92 

0,5-1 
0-1 
0,8-1,25 

Leq 

51,40 
52,01 
52,30 
51,55 
51,67 
52,84 

Leq- 
A-corrected

45,10 
44,20 
41,62 
40,55 
40,88 
39,34 

4.16.6-Table 31 
Sound level reduction by primary silencer B1 

Without 
Silencer 
(0) 

LAeq  [dB] 
Leq  [dB] 
LAmax  [dB] 
LAmin  [dB] 
Lmax  [dB] 
Lmin  [dB] 

48,1(48,1) 
67,7(55,1) 
49,4 
47,0 
74,1 
56,5 

C-Profiles 
screwed at 
the ends 
(a) 
49,4(49,6) 
58,2(56,4) 
50,6 
48,5 
63,3 
54,8 

C-Profiles 
screwed 
Standard 
(b) 
51,7(51,6) 
58,6(57,2) 
53,0 
50,5 
61,7 
55,9 

C-Profiles 
Standard 
Mineral 
Wool (c) 
49,7(49,6) 
57,9(57,3) 
50,8 
48,7 
61,2 
55,3 

Timber 
screwed 
glued 
(d) 
50,7(50,6) 
57,9(55,7) 
52,0 
49,6 
61,4 
54,8 

4.16.7-Table 32 
Secondary silencer type I 

107 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
nx 
1 
0 
0 
1 
1 
0 
2 
0 
0 
2 
2 
0 
1 
1 
0 

ny 
0 
1 
0 
1 
0 
1 
0 
2 
0 
1 
0 
2 
2 
0 
1 

nz 
0 
0 
1 
0 
1 
1 
0 
0 
2 
0 
1 
1 
0 
2 
2 

f[Hz] 
31,5 
55,0 
61,3 
63,4 
68,9 
82,3 
63,1 
109,9 
122,5 
83,6 
87,9 
125,8 
114,4 
126,5 
134,3 

4.16.8-Table 33 
Room Modes Frequencies 

W2F-10  W2F_50_3  W2F_51_3 W2F_70_3 W2F_71_3 W2F_60_3

W2F_80_3
n 

W2F_80G3
n 

W2F_90_3
n 

nz 

3.16.9.1  3.16.9.2

3.16.9.3

3.16.9.4

3.16.9.5

3.16.9.6  3.16.9.7  3.16.9.8

42,3 
-4,5 
53,0 
43,6 
41,3 
58,1 
48,3 

39,7 
-7,1 
53,1 
43,2 
40,3 
57,1 
48,8 

44,0 
-2,8 
56,8 
47,3 
44,7 
61,5 
52,4 

45,1 
-1,7 
55,2 
48,4 
46,0 
59,2 
51,8 

46,4 
-0,4 
57,5 
49,8 
47,3 
62,1 
53,5 

46,3 
-0,5 
57,3 
49,7 
46,9 
61,8 
53,7 

36,2 
-10,6 
54,4 
37,8 
ny 
34,8 
60,1 
48,5 

39,0 
-7,8 
55,3 
40,4 
37,6 
61,0 
49,5 

50,6 
3,8 
nx 
56,3 
52,0 
49,2 
60,1 
54,2 

4.16.9.9 -Table 34 
Sound levels in dB from section 4.16, Secondary silencer II , wall double planked7 

l/h 
l/min 

Parameter 
LAeq 
Leq 
LAmax 
LAmin 
Lmax 
Lmin 

INS 
950 
15,83 
Mean 
[dB] 
33,8 
51,6 
35,0 
32,8 
57,6 
45,5 

Type A 

Type B 

1080 
18 
Mean 
[dB] 
23,9 
54,3 
25,2 
23,0 
58,8 
47,4 

3360 
56 
Mean 
[dB] 
29,6 
55,1 
30,8 
28,5 
61,1 
48,2 

1080 
18 
Mean 
[dB] 
27,2 
53,1 
28,2 
26,1 
59,6 
44,0 

2880 
48 
Mean 
[dB] 
37,2 
54,1 
38,6 
35,9 
61,0 
47,3 

4.17-Table 35 
Wall W2F, Airborne sound level of ¾"-valve (A) and ½” (B) , not classified 

Report 
section 

LAeq  [dB] 

INS 46,8 

Leq  [dB] 
LAmax  [dB] 
LAmin  [dB] 
Lmax  [dB] 
Lmin  [dB] 

108 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
INS 

Type A ¾” 

Type B ½” 

l/h 
l/min 

Parameter 
LAeqINS 
LLeqINS 
LAFmaxINS 
LAFminINS 
LLFmaxINS 
LLFminINS 

950 
15,83 
Mean 
[dB] 
42,3 
53,0 
43,6 
41,3 
58,1 
48,3 

1080 
18 
Mean 
[dB] 
26,4 
53,4 
29,6 
27,4 
58,5 
47,2 

3360 
56 
Mean 
[dB] 
38,2 
54,1 
41,9 
39,1 
58,7 
49,5 

1080 
18 
Mean 
[dB] 
32,6 
54,4 
35,8 
33,7 
61,4 
47,9 

2880 
48 
Mean 
[dB] 
45,1 
55 
48,6 
46,1 
60,2 
53,1 

4.17-Table 36 
Wall W2F, Sound level of ¾"-valve (A) and ½”-valve (B) , not classified, clamped 

109 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
List of Figures 

3.1-Fig. 18  
3.1-Fig. 2 
3.1-Fig. 3 

Show steel house in Eisenhüttenstadt, Germany, constructed by FQZO, 2003 
Steel skeleton of the show house with the basic distance  612 mm 
Light gauge wall assemblage of three modules 

3.4-Fig. 4 

Thermal insulation with thermal mineral wool (show house) 

3.5-Fig. 5 
3.5-Fig. 6  
3.5-Fig. 7 

Dry lining modules 
Combined light gauge wall assemblage 
Earth quake version (Turkish Norm) 

3.6-Fig. 8 
3.6-Fig. 9 

The features of fitting noise propagation 
Oscillator model for the wall vibration transport 

3.7-Fig. 10 
3.7-Fig. 11 

A-Correction or weighting characteristics 
Detrimental impact of  continuous sound levels 

3.8-Fig. 12     Sound lab FQZ 
3.8-Fig. 13 
3.8-Fig. 14 
3.8-Fig. 15 
3.8-Fig. 16 

Pressure vessel (in front) with pump and reservoir (behind) 
Completed sound room for fitting noise measurements, FQZO 
Installation Noise Standard Generator 
Sound Level Spectrum of the Installation Noise Standard in one-third Octave Steps 

3.9-Fig. 17 
3.9-Fig. 18 
3.9-Fig. 19 

Former power control building, red rectangle lab position FQZO 
Acoustic lab ISQ in a garage  
Draft acoustic lab ISQ 

3.10-Fig. 20   Measurement of fitting noise according to EN ISO 3822-1 and to AFINOPRO 

3.11.1-Fig. 21  Vibration insulation 
3.11.2-Fig. 22  Microphone positions in the measurement or microphone room 
3.11.3-Fig. 23  External Noise Level FQZO/ISQ 

3.12.1-Fig. 24  Measurement with placement 1 
3.12.1-Fig. 25  Measuring wall during and after installation (installation room side) 
3.12.1-Fig. 26  Measuring wall (measuring room side)  
3.12.1-Fig. 27  Fastening details. Supplementary pipe fastening on a C-profile 
3.12.1-Fig. 28  GF Sound level in dependence on the fastening technique, A-corrected 
3.12.3-Fig. 29  Cross measurements Leq GB /GF 
3.12.3-Fig. 30  Cross Measurements Leq GB/GF, Noise-cleared 
3.12.3-Fig. 31  Cross measurements Leq GB/ GF, Noise-cleared, A-corrected 
3.12.5-Fig. 32  Earthquake version Wall W-9F-10 (Turkish norm) 

3.13-Fig. 33   Basic wall with basic pipe clamping positions 
3.13.1-Fig. 34  Transmission and filtering of INS vibration generation 
3.13.2-Fig. 35  Single modules (a) domestic application, (b) simulation conditions 
3.13.2-Fig. 36  (a) Hard fastened U,C-Profiles, (b) nearly free C-Profiles 
3.13.2-Fig. 37  Load Case 1 
3.13.2-Fig. 38  Load Case 2 
3.13.2-Fig. 39  Load Case 2 
3.13.2-Fig. 40  Load Case 2 
3.13.2-Fig. 41  Vibration characteristics 

8 The label contains the section number to which the figure belongs, followed by  “Fig.” and a control number 

111 
 
 
 
 
 
 
 
 
 
 
 
 
 
                                                 
3.13.2-Fig. 42  Point or node connection 
3.13.2-Fig. 43  Load case 3 
3.13.2-Fig. 44  Load case 4 
3.13.2-Fig. 45  Corner of the module with U (blue), C-beam, wall 1 and 2 
3.13.2-Fig. 46  Selection of master & slave surfaces (Wall to U-beam) (a), tie created (b) 
3.13.2-Fig. 47  Assembly 1250x2500 mm2, node tied 
3.13.2-Fig. 48  Boundary conditions for the module 
3.13.3-Fig. 49   First eigenfrequency at mx = my = 1, 10,743 Hz 
3.13.3-Fig. 50  Ninth eigenfrequency at mx = 2, my = 3 at 27,315 Hz 
3.13.4-Fig. 51   Assembly with contact ties (yellow) between C, U-profiles and panels 
3.13.4-Fig. 52   First mode at  =  5.71 Hz 
3.13.4-Fig. 53   Fifth mode at  =  13.25 Hz 
3.13.4-Fig. 54  Details of Fig. 53, fifth mode 
3.13.5-Fig. 55  Measurement of perpendicular vibrations (x) of pipe and plate on the wall 
3.13.5-Fig. 56  Measurement of longitudinal (y) and perpendicular vibration (x) of the wall 
3.13.5-Fig. 57   Co-ordinate system for vibration measurements 
3.13.5-Fig. 58   Acceleration Spectra of Pipe(x) and Wall(x) Pipe Side , 0-10000 Hz 
3.13.6-Fig. 59  Measurement of vibration transport by members 
3.13.6-Fig. 60  Measurement positions for vibration measurements 
3.13.6-Fig. 61  Uniform vibration by airborne sound (a) and bending vibration by spot excitation (b) 

3.14-Fig. 62  Measurements with the placement 2  
3.14-Fig. 63  Wall connections used in the project 
3.14.1-Fig. 64   Placement 2, wall W-1F-2A, microphone room 
3.14.1-Fig. 65   Placement 2, wall W-1F-2D, microphone room 

3.15-Fig. 66  Measurements with the placement 2  
3.15-Fig. 67   Placement 3, wall W2F-3D, mounting room 
3.15-Fig. 68   Placement 3, wall W2F-3D, mounting room 

3.16.4-Fig. 69  FEM Simulation of the experimental arrangement 
3.16.4-Fig. 70  Transversal (x), Transversal (y), Thickness Modes  
3.16.4-Fig. 71  Vibration modes of the pipe of Fig. 69, inclusive table with mode type 
3.16.4-Fig. 72  (a) Mixed thickness+transversal(x) mode and (b) transversal(y) mode  
3.16.5-Fig. 73   Pipe (P0) 
3.16.5-Fig. 74   Barrier 1 (B1) 
3.16.5-Fig. 75  Sound barrier family 
3.16.5-Fig. 76   Barrier 3 (B3) 
3.16.5-Fig. 77   Barrier 4 (B4) 
3.16.5-Fig. 78  Modal analysis for different versions of B1 barriers to B4 barrier 
3.16.5-Fig. 79   Spectral Amplitude (SA) pipe P0  
3.16.5-Fig. 80   (SA) according to Fig. 43 
3.16.5-Fig. 81   (SA) according to Fig 76 
3.16.5-Fig. 82   (SA) according to Fig. 46  
3.16.6-Fig. 83   Silencer with wall W-9F-10u (u for U-Silencer)  
3.16.6-Fig. 84   Silencer with supplementary damping 
3.16.6-Fig. 85   Silencer with supplementary damping, diagram 
3.16.7-Fig. 86  Variants of secondary silencer 
3.16.7-Fig. 87  Sound level spectra of the silencer variants of Fig. 86 
3.16.8-Fig. 88  First, second and third room modes 
3.16.8-Fig. 89  Microphone positions in the mounting room 
3.16.8-Fig. 90  Sound level in the mounting room at all microphone positions 
3.16.8-Fig. 91  Airborne sound level in the microphone room coming from the mounting room 
3.16.8-Fig. 92  Pressure distribution at 0.0275s after the sound source started 

112 
 
 
 
 
 
 
 
3.16.9.1-Fig. 93 
3.16.9.1-Fig. 94  
3.16.9.2-Fig. 95  
3.16.9.3-Fig. 96 
3.16.9.4-Fig. 97 
3.16.9.5-Fig. 98 
3.16.9.6-Fig. 99 
3.16.9.7-Fig. 100 
3.16.9.9-Fig. 101  
3.16.9.9-Fig. 102  
3.16.9.9-Fig. 103  

3.17-Fig. 104    
3.17-Fig. 105     

3.17-Fig. 106 
3.17-Fig. 107     

Wall with anti drum tape inside  
Anti drum tape, draft 
Anti drum tape between the panels, draft  
Inner layer for impact sound (a) between the panels, (b) wall closed  
Screws draft for each single module  
Inner layer of acoustic foam (a) between the panels, (b) wall closed  
Partition layer between members and boards  
Split boards in the mounting room  
A-corrected sound level for the best wall variants of section 3.16 
A-corrected sound level for the bad wall variants of section 3.16 
A-corrected sound level for the wall variants 3.16.1, 3.16.2, 3.16.4 

¾"-valve (A), ½”(B) , not classified 
A-corrected sound level  at 3 bar in dependence of the water flow for tap A , B 
not-classified, clamped 
A-corrected Sound level of a ¾” (A) valve for flow = 18, 56 l/min 
A-corrected Sound level of a ½” (B) valve for flow = 18, 48 l/min 

113 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
  
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
3.2-Table 19 
3.3-Table 2 
3.3-Table 3 
3.8-Table 4 

3.11.3-Table 5   

3.11.3-Table 6   

3.12.2-Table7 

3.12.2-Table 8 

3.12.3-Table 9   

3.12.3-Table 10 

3.12.4-Table 11 

3.12.5-Table 12 

3.12.5-Table 13 

3.12.5-Table 14 

3.12.5-Table 15 

3.13.6-Table 16 
3.14.1-Table 17 

3.14.1-Table 18 

3.14.1-Table 19 

3.14.1-Table 20  

3.14.1-Table 21 

3.14.1-Table 22 

3.15.1-Table 23 

3.15.1-Table 24  

3.15.1-Table 25 

3.15.1-Table 26 

List of Tables 

Member specification 
Boards properties 
Mechanical properties of wall planking/steel, details 
A-corrected reference sound level of the INS according to EN-ISO-3822-1,  
LAeq = 46.8 dB 
Mean of A-weighted and unweighted external noise level FQZO-lab 
Green highlighted: frequency range 100-5000Hz.Others 16-12500 Hz 
Mean of A-weighted and unweighted external noise level ISQ-lab 
Light green frequency range 100-5000Hz, Others 16-12500 Hz 
* only average of Mic 2 and Mic 3 according to EN ISO 3822-1 
Gypsum fibreboard; A-weighted and unweighted sound level 
of INS at 3 bars, clamps fastening according to EN ISO 3822-1 
Gypsum fibreboard; A-weighted and unweighted sound level  
of INS at 3 bars, clamps fastening only on pipe side wall 
FQZO-Measurement W1G-11 Single wall (gypsum) 
A-weighted and unweighted sound level LCS of INS at 3 bars, clamped  
Yellow line: sound level  A-corrected +noise cleared 
ISQ-Measurement W1G-1_0 Single wall (gypsum) 
A-weighted and unweighted sound level LCS of INS at 3 bars, clamped  
Yellow line: sound level A-corrected +noise cleared 
Sound level Leq and LAeq for gypsum board and gypsum fibreboard, FQZO- 
measurements  
Placement 1 : Sound level of the different walls, pipe free floating (airborne 
sound) 
Placement 1 : Sound level of the different walls, pipe clamped   
Turquoise highlighted line : difference of the first line to the INS level 
Calculated and measured modes for a module 2,50 x 1,25m 
Light green : matching within  2 Hz, green :  1 Hz 
Calculated and measured modes for a wall 2,50 x 3,75 m 
Light green: matching within  2 Hz, green :  1 Hz 
Relative vibration energy of members 
Placement 2, Wall connection A : Sound level, pipe free floating  
(airborne sound) 
Placement 2, Wall connection A : Sound level, pipe clamped   
Turquoise highlighted line : difference of the first line to the INS level 
Placement 2, Wall connection C : Sound level, pipe free floating  
(airborne sound) 
Placement 2, Wall connection C : Sound level, pipe clamped   
Turquoise highlighted line : difference of the first line to the INS level  
Placement 2, Wall connection D : Sound level, pipe free floating  
(airborne sound) 
Placement 2, Wall connection D : Sound level, pipe clamped 
Turquoise highlighted line : difference of the first line to the INS level 
Placement 3, Wall connection A : Sound level, pipe free floating  
(airborne sound) 
Placement 3, Wall connection A : Sound level, pipe clamped 
Turquoise highlighted line : difference of the first line to the INS level 
Placement 3, Wall connection C : Sound level, pipe free floating  
(airborne sound) 
Placement 3, Wall connection C : Sound level , pipe clamped 
Turquoise highlighted line : difference of the first line to the INS level 

9 The label contains the section number to which the table belongs, followed by  “Table.” and a control number 

115 
 
 
 
 
 
  
                                                 
3.15.1-Table 27 

3.15.1-Table 28  

3.15.1-Table 29 

3.16.2-Table 30 

3.16.6-Table 31 
3.16.7-Table 32 
3.16.8-Table 33 
3.16.9.9 -Table 34 

3.17-Table 35  
3.17-Table 36 

Placement 3, Wall connection D : Sound level, pipe free floating  
(airborne sound) 
Placement 3, Wall connection D : Sound level, pipe clamped 
Turquoise highlighted line : difference of the first line to the INS level 
Vibration sound level transported by the connections A,C,D, i.e. difference 
between the fitting noise and airborne sound level 
Sound level reduction by jacketing the pipe with acoustic foam  
partial : jacketing of  the pipe along the lab envelope only 
complete : jacketing of the complete pipe inclusive along the test wall 
Turquoise highlighted line : difference of the first line to the INS level 
Sound level reduction by primary silencer B1 
Secondary silencer type I 
Room modes frequencies 
Sound levels in dB from section 3.16, Secondary silencer II , wall double 
planked 
Turquoise highlighted line : difference of the first line to the INS level 
Wall W2F, Airborne sound level of ¾"-valve (A) and ½” (B) , not classified 
Wall W2F, Sound level of ¾"-valve (A) and ½”-valve (B) , not classified 

116 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
List of Acronyms, Abbreviations 

Gypsum board 
Gypsum Fibreboard 

G 
F 
OSB  Oriented Strand Board 
FEM  Finite Element Method 

(CR1)  Universidad Polytécnica de Madrid 

UPM 
FQZO  (CRO)  Forschungs- und QualitätsZentrum Oderbrücke 
ISQ 

(CR3)  Instituto de Soldadura e Qualidade 

INS  

Installation Noise Standard 

EN 

External Noise 

FN 

Fitting Noise 

LFN 

Fitting noise/sound level 

LEN  

external noise/sound level  

LCS  

common sound level 

LL 

Sound level, any 

WallP  Wall side facing to the pipe (and therefore to the mounting room) 

WallM  Wall side facing to the microphones (and therefore to the measurement or microphone room) 

B1..4  Sound barrier 1 … 4 

SA 

Spectral amplitude 

CP1..4  Clamp position 1..4 

P1..4  Position 1..4 

P0 

straight pipe 

Leq 

equivalent noise level 

mn 

radiant frequency of mode m,n 

E 

h 

Young module in N/mm2 

thickness 

En 

Energy 

meff,k 

effective mass 

117 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
Wall Description 

  W_1 G_3_A 

Wall 

Wall variant:   

Panel material:              Gypsum  

 Gypsum Fibreboard 

Placement: 

Wall connection: 

1 

3 

A 

Wall Description 

  W  2  F- 1  0   

Wall 

Wall variant:   

Panel material:              Gypsum  

 Gypsum Fibreboard 

Placement: 

Wall connection: no connection 

2 

1 

0 

118 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
References 

[1]      VOSKUILEN R, BEENTJES W, MARELet all. Den Haag: Ministerie van VROM, 1993. 

(incl bijlagenrapport 6599, Bouwcentrum Advies, 1993). DGVH/DOK rapport nr. 11. 

[2]  

Gösele, K, Engel, V. :Der Einfluß der Bauart und der Grundrißgestaltung auf das Entstehen .
von Installationsgeräuschen in Bauten,, Gesundheits-Ingenieur 101 (1980) S 

John J. Van Houten, Control of plumbing noise in buildings, Plumbing Systems & Design,  

[3]    
          March/April 2003, Page 30 

[4]     Fuchs, H.V., Klöppner, U : Einige Mechanismen der Geräuscherzeugung in Wasserarmaturen. 
          Bericht des Frauenhofer-Institutes für Bauphysik, BS 62/81 (1981) 

 [5]     Fuchs, H.V. : Geräusche von Armaturen von Wasserinstallationen. . Bericht des Frauenhofer- 

Institutes für Bauphysik, BS 76/82 (1982) 

[6]     Evaluación de las emisiones de ruido producidas por instalaciones de  fontanería  
          T. Lorenzana Lorenzana *; M.D. Salgado Carballo *; J. González Suárez ** II jornadas 

iberoamericanas de acústica. eaa symposium on architectural acoustics, Madrid. Octubre, 2000 

[7]     EN ISO 3822-1 „Laboratory tests on noise emission from appliances and equipment used in 

water  supply installations” 

[8]     EN ISO 10052,” Acoustics -- Field measurements of airborne and impact sound insulation and 

of service equipment sound -- Survey method 

[9] 

DIN EN 61672-1 Electro acoustics Sound level meters Part 1 : Specifications 

[10]  DIN EN ISO 717-1 Rating of sound insulation in buildings and of building elements Part 1 

Airborne sound insulation 

[11]  DIN EN ISO 140-3 Acoustics Measurement of sound insulation in buildings and of buildings 
elements. Part 3. Laboratory measurements of airborne sound insulation of building elements 

[12]  DIN 45641 

Averaging of sound levels 

[13]  DIN 52221 

Bauakustische Prüfung; Körperschallmessungen bei haustechnischen Anlagen 

[14]  DIN EN 14195 Metal framing components for gypsum plasterboard systems 

Definition, requirements and test methods 

[15]   M.M. Filonenko.-Boroditsch  Elastizitätstheorie 

119 
 
  
 
 
 
 
 
         
 
         
 
      
 
        
 
 
 
 
 
 
  
 
 
 
 
 
 
 
 
 
 
 
 
APPENDIX 1  Quantities  

Pressure 

 p  

Frequency, Frequency Band Centre 

Reference Value of Pressure  

Reference Value for Particle Velocity 

 

p0 

v0 

   [Pa]

   [Hz] 

 20  

 [µPa] 

         5,010-8       [ms-1] 

Sound Pressure Level Lp(,t) 

                 p2(,t) 
Lp(,t)  = 10log  

                   p0

2

                 n 
 
Lp(t)    = 10 log     10Lp(i,t)/10 
Total Sound Pressure Level 
n number of frequency bands i  measured                                                   i=0 
                                                                                                                                                                                                      T

   [dB] 

   [dB] 

Equivalent Continuous Sound Level 

Lp() 

   dt  

   [dB] 

                                                                                                                                                                                                    0 

   1 
 = 10log     10 
    T 

   Lp(,t)/10 

            T 
1 

         Lp(t)/10 

Equivalent Total Continuous Sound Level 

Leq 

 =   10log      10 
                  T 

  dt  

   [dB] 

                                                                                                                              0 

A-weighted Equivalent Continuous  
Sound Level 

LAeq(i)  =   10log[10Leq()/10+A()/10]         [dB] 

        n 

Total A-weighted Equivalent Continuous 
Sound Level                                                                                                  i=0 

LAeq 

= 10 log     [10(Leq()/10+A())/10] 

   [dB] 

 

Fast A-weighted Equivalent Continuous  
Sound Level   
no pulse, duration longer than 200 ms  

harmonic air particle velocity  

Acoustic impedance 

sound velocity in air  

density  

middle frequency  

A-corrected external noise level (EN) 

LFAeq     = LAeq and T > 200 ms   

   [dB] 

v  

Z 

c    

m 

LA,EN 

 

 [ms-1] 

           Ns/m3]

 [ms-1] 

           [kgm-3]

   [Hz] 

                         [dB] 

121 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
     
 
 
 
 
 
 
 
 
 
                                                                                                    
 
 
 
   
 
 
 
 
 
                             
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
     
 
 
  
 
 
 
 
                                                   
           
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
APPENDIX 2   Walls arrangements    

Variants for non load-bearing walls, metal thickness 0.6 mm for profiles6 

1.  Wall thickness 125 mm, planking per side 12.5 mm   

panel material A 
panel material B 
Mineral wool 

panel material A 
panel material B 
Mineral wool 

panel material A 
panel material B 
Mineral wool 

panel material A 
panel material B 
Mineral wool 

2.  Wall thickness 145 mm, planking per side 12.5+10 mm   

3.  Wall thickness 135 mm, planking per side 12.5 mm 

4.  Wall thickness 155 mm, planking per side 12.5 + 10 mm 

6 A - gypsum board 

 B- gypsum fibreboard  

123 
 
 
  
 
 
 
 
 
 
 
  
 
 
 
 
 
 
 
 
  
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
  
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
  
 
 
 
 
 
 
 
  
 
  
 
 
 
 
 
 
 
 
  
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
  
  
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
                                                 
 
 
 
 
Variants for load-bearing walls, metal thickness 1.5 mm for profiles7 

5. Wall thickness 141.5 mm, planking: Panel materials are of 12.5 + 10 mm  

    Panel material C 19 mm 

panel material A or B 
panel material C  
mineral wool 

6. Wall thickness 245.5 mm, planking: Panel materials are of 12.5 + 10 mm,  

    Panel material C 19 mm, rigid foam 100 mm 

panel material A or B  
panel material C  
mineral wool  
rigid foam 

No-coherent wall modules, metal thickness 0.6 mm for profiles 

New wall developments 

7. Wall thickness 125 mm, planking per side 12.5 mm,   

panel material A or B 

Mineral wool 

7 A - gypsum board 

 B- gypsum fibreboard  

 C- OSB  

rigid foam : polystyrene 

124 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
  
 
 
 
 
 
 
             
 
  
 
 
 
 
             
 
 
 
  
 
 
             
 
 
 
 
 
  
 
           
 
 
 
 
 
 
  
 
 
 
 
 
 
 
 
 
 
  
 
 
 
 
 
 
 
 
  
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
                                                 
 
 
 
 
 
8. Wall thickness 145 mm, planking per side 12.5 mm +10 mm8  

panel material A or B  

Mineral wool 

9. 

Earth Quake suitable wall, Turkish norm, metal thickness 1.5 mm for profiles  

panel material A or B 
mineral wool  

diagonal stripes 

8 A - gypsum board 

 B- gypsum fibreboard  

125 
 
 
 
 
 
 
 
 
 
 
 
  
 
 
 
 
 
 
 
 
  
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
  
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
                                                 
 
 
 
 
 
Screwing on profile without inter-insulation with drywall filler 

Wall connection A 

panel 
drywall filler 
mineral wool 
drywall screw 

panel 
drywall filler 
mineral wool 
drywall screw 

Wall connection A (double-planked) 

 panel   
 drywall filler 
 mineral wool 
 drywall screw 

126 
 
 
  
 
 
 
 
 
 
 
  
  
 
 
 
 
 
 
 
 
 
 
 
   
 
 
 
 
 
 
 
 
  
   
 
 
 
 
 
 
 
 
 
   
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
Wall connection B/C 
Screwing on profile with inter-insulation and elastic seal 

 panel   
 drywall filler 
 mineral wool 
 drywall screw 

Panel 
drywall filler (B) 
elastic seal     (C) 
mineral wool 
elastic stripes 
drywall screw 

Panel 
elastic seal 
mineral wool 
elastic stripes 
drywall screw 

127 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
      
 
 
 
 
 
 
 
 
 
  
      
 
 
 
 
 
 
 
 
 
 
      
 
 
 
 
 
 
 
 
 
      
 
 
 
 
 
 
 
 
 
      
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
Screwing on profile with elastic inter-insulation  

Wall connection C (double-planked) 

Screwing on planking without inter-insulation  

Wall connection D  

Panel 

mineral wool 
elastic stripes 
drywall screw 

Panel 

mineral wool 
elastic stripes 
drywall screw 

 panel   
 drywall filler 
 mineral wool 
 drywall screw 

128 
 
 
 
 
 
 
 
 
 
 
 
 
 
      
 
 
 
 
 
 
 
 
 
      
 
 
 
 
 
 
 
 
 
      
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
      
 
 
 
 
 
 
 
 
 
      
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
    
 
 
 
 
 
 
 
 
  
    
 
 
 
 
 
 
 
 
  
 
 
 
 
 
 
 
 
 
 
    
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
Screwing on planking without inter-insulation  

Wall connection D (double-planked) 

 panel   
 drywall filler 
 mineral wool 
 drywall screw 

Planking Rules: main wall and secondary wall single or double planked never 
different 

 panel   
 drywall filler 
 mineral wool 
 drywall screw 

 panel   
 drywall filler 
 mineral wool 
 drywall screw 

129 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
  
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
  
 
 
 
 
 
 
 
 
 
 
   
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 panel   
 drywall filler 
 mineral wool 
 drywall screw 

Measurement arrangements  

Measurement placement 1 

Measuring 
plumbing 

Installation 
Noise 
Standard 

Measurement placement 2 

Measuring 
plumbing 

Installatio
n Noise 
Standard 

4
3

2

1

4
3

2

1

Measuring wall 

Measuring room 

Pipe clamps 

Measuring 

ll

Measuring 

Pipe clamps 

130 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
Measurement placement 3 

Pipe clamps 
2
1
4

3

Measuring wall 

Measuring room 

Installation 
Noise 
Standard

Measuring 
plumbing 

Measurement placement 4 

Pipe clamps 
2
1
43

Installation 
Noise 
Standard

Measuring 
plumbing 

1 to 4  -  Fixing points 

Measuring wall 

Measuring room 

131 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
APPENDIX 3   

ADVANCED PLUMBING SOLUTIONS 

INTRODUCTION 

Light gauge steel constructions become state of the art quality in modern buildings related to public and 
private living sphere. 
During the last decades most of the problems concerning noise in relation with low mass constructions 
have been solved or at least reduced. Airborne sound in public 
rooms  and  its  propagation  through  walls  has  been  reduced  considerably  by  the  development  of  new 
mineral wool products with well-defined acoustic damping properties. 
Nevertheless  fitting  noise  differs  rather  from  the  above-mentioned  airborne  sound  because  it  exploits 
the excellent vibration properties of light gauge constructions. 
Not the fitting noise itself is the lonely bad source but finally the complex compound consisting of noise 
agent  the  fitting,  resonator  the  wall,  the  transmitter  the  pipe,  the  steel  members,  the  board  and  the 
unions between all the elements. 
The  planking,  which  finally  defines  the  wall  limits,  is  indeed  a  huge  loudspeaker  membrane  able  to 
transmit every domestic noise frequency. 
The use of rubber or elastic foam to damp the mechanical vibrations is never effective. 
Rubber is incompressible. Pressurised elastic foam looses mainly its damping properties the higher its 
density is. Organic materials suffer always of an evaporation of chemical components especially under 
the influence of light and heat so their properties deteriorate in time. 
Beyond it nobody tights a screw with a torque spanner in the building site as it would be necessary to 
obtain the optimal damping properties of the material. So the use of organic damping materials in 
buildings is more a reassurance than a real improvement. 
Therefore solutions are needed which are robust, redundant against bad business and stable in time. 
Moreover they must be simple, realisable without large efforts and cheap. 
Last but not least they must be effective without the need of special tooling or skilled people. 
On one hand these are a lot of restrictions, which reduce every design possibility. 
On the other hand they become feasible and therefore attractive. 

ADVANCED PIPE DESIGN 

In analogy to bows of warm water or steam supply in district heating, bows can take on the vibration 
energy transmitted by a pipe because they act like a leaf spring. 
In heating systems the bow takes the static elongation of the pipe, in vibrational systems the dynamic 
elongation of the pipe. 

Whereas the static elongation is totally accommodated by a simple bow, in the dynamic case the bow is 
also a vibrational element but with eigenfrequencies differing from that of the pipe. 
Therefore  it  acts  like  a  frequency  filter  or  sound  barrier  for  the  vibration  frequencies  of  the  pipe 
differing from its own eigenfrequencies.  

Nevertheless to obtain optimal results several bows must be connected to each other. 
Depending on the design and number of bows different level of filtering are reached.  

133 
 
 
  
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
THE SOUND BARRIER FAMILY  

B1 

B2 

B4 

Fig. 1   Sound barrier family 

B3 

134 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
FILTER PROPERTIES 

Amplitude A(y) at clamp CP1 of Pipe P0

4

3,5

3

2,5

2

1,5

1

0,5

m
m
n

i

e
d
u
t
i
l

p
m
A

0

0

5

4,5

4

3,5

3

2,5

2

1,5

1

0,5

m
m
n

i
e
d
u
t
i
l

p
m
A

0

0

6

5

4

3

2

1

m
m
n

i
e
d
u
t
i
l

p
m
A

0

0

4,5

4

3,5

3

2,5

2

1,5

1

0,5

0

0

m
m
n

i

e
d
u
t
i
l

p
m
A

2000

4000

6000

8000

10000

12000

14000

16000

Mode frequency in Hz

Amplitude A(y) at CP1 and CP2 for Barriers B1, -B1

CP1
CP2

CP1

CP2

2000

4000

6000

8000

10000

12000

14000

Frequency in Hz

Vibration Amplitude A(y) at the clamping CP1 and CP2 

2000

4000

6000

8000

10000

12000

14000

Mode Frequency in Hz

Amplitude A(y) at CP1 for Barrier B4

2000

4000

6000

8000

10000

12000

Frequency in Hz

Fig. 2  Filtering of straight pipe vibration by sound barriers B1 and B4, left arrangement, right 
vibration spectra, material stainless steel, bent  

135 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
DAMPING 

The power of active filtering by advanced pipe design has been shown in the former page for different 
barriers. 

Nevertheless the better the damping of the material the lower the sound transmitted. 
Although  pipe  bending  of  steel  material  is  a  rational  process  and  the  positive  results  of  Fig.  2  are 
obvious, the damping properties of the most flexible steel grades are rather poor. 

Therefore better materials compatible with steel are recommended. 
Cast iron is the first choice for metallic damping materials. The names of cast iron materials are ruled 
by the standard EN 1560 

Within the cast iron family there are two important groups, the non- or lightly malleable materials, for 
example  

- 
- 

EN GJL-150 
EN GJS-350-10 

G  =  cast,  J  =  Iron,  L  :  lamellar  ,  S  :  spherical,  first  number  :  tensile  stress,  second  number  :  fracture 
strain in %  

The most interesting material with high damping properties due to the lamellar graphite structure is the 
GJL cast iron or grey iron. It is not ductile, so the second number doesn’t appear, it is brittle and has 
therefore a low breakage level. It is relatively stiff. 

The  commonly  used  cast  iron  material  in  commercial  immediately  available  fittings  is  the  so-called 
malleable cast iron, which names are ruled in the DIN EN 1562, for instance 

- 
- 

EN GJMW-350-4 
EN GJMW-400-5 

G = cast, J = Iron, M : malleable, W :white (fracture area : white) first number : tensile stress, second 
number : min. elongation % (sample diameter 12 mm) 

It has lower damping properties than the grey cast iron GJL (fracture area : grey) but still better ones 
than (stainless) steel bows. 

BASIC ELEMENT 

It  is  surely  possible  to  order  a  complete  sound  barrier  according  to  Fig.  1  because  a  lot  of  foundries 
offer lot size ordering at low costs but finally water supply is a system, which stays always in the non-
public area and is only perceived when it makes noise. 
Therefore the assembling on the base of fitting elements is an effective way. 
Of course the danger of leakage raises with the number of connections (5 or 9).  

The basic element is the long bow 3/4 G4 according to ISO 49 of GJMW. better GJL material. 

136 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
  
 
 
 
 
 
 
 
 
 
Fig. 3 Basic Element 

 Fig. 4 Barrier B1 

Fig. 5  Barrier B3 

137 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
  
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
Research Programme of the Research Fund for Coal and Steel 
Steel RTD  

Project carried out with a financial grant of the  
Research Programme of the Research Fund for Coal and Steel 

Analysis of fitting noise propagation in steel 
lightweight constructions and design solutions 
for their prevention 

Guidelines 

139

139 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
APPENDIX 4 

Advanced Solutions for Silent Plumbing Design in Dry Construction  

1. 

Plumbing Noise 

Although nobody needs to be taught was plumbing noise is because under certain conditions he suffers 
every day or night from it, it is informative to situate it in the palette of noises we are subjected to. 
From the noise protection point of view of the same rules and limits are valid for plumbing and fitting 
noise namely 30dB. 

Pain Barrier 

Hearing Degradation 

Drop in Productivity 

Communication 
Disorder 
Learning and 
Concentration 

Sleep Disorder 

Normal Conversation 
50-60 dB 

Whisper 
30 dB

Low 
Breathing

20 dB

40 dB

60 dB

80 dB

100 dB  120 dB 

Fig. 1 
Equivalent Continuous Sound Level 

Regarding to what 30 dB means we can conclude from Fig. 1 that fitting noise mustn’t be stronger than 
whisper in any room outside of the place, where the fitting is turned on. On one hand it is a very hard 
requirement. On the other hand looking at Fig. 1 the disturbance of human recuperation begins already 
at the perception of very low sound. 

A-corrected sound level at 3 bar in dependence of the water flow for tap A, B 
non-classified 

50

45

40

35

30

25

B
d
n

i

l
e
v
e
l

d
n
u
o
S

20

10

A
B

15

20

25

30

35

40

45

50

55

60

AFINOPRO_Abschlußbericht.xls

Water flow in l/min

Fig. 2 
A-corrected sound level  at 3 bar in dependence of the water flow for tap A , B 
not-classified 

141 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
The noise level in dependence of the water flow in l/min for non-classified fittings (A, B) can be very 
different by chance as it can be taken from Fig. 2.   

Absolutely  seen  plumbing  noise  is  not  so  very  loud.  Nobody  in  a  full  café  will  perceive  the  noise 
somebody produces in the lavatory letting the water run at full open tap with 51 dB. 
The impact of plumbing noise is due first of all to its intermittent appearance in a surrounding being 
quiet when people recover or work very concentrated for instance in offices, make homework or sleep. 
We must not forget that human spend 1/3 and more of the whole life sleeping and recovering passive. 

2. 

Plumbing noise reduction, how 

Speaking about fitting and plumbing noise it should be clear that the final sound we perceive is not the 
sound of the fitting or plumbing but the sound of the walls of the room in which we are sitting. 
The wall has been put in vibration by the plumbing attached to it. 
In  the  acoustic  sense  a  wall  is  a  loudspeaker  membrane  put  in  motion  by  a  mechanical  exciter,  the 
fitting and we sit inside the loudspeaker, the room. 

To  have  results,  which  can  be  generalised  we  use  a  reference  noise  source  the  so-called  Installation 
Noise (Transfer) Standard, (acronym INS) to test and improve the performance of the wall and silencers 
designs. 
With  an  A-corrected  equivalent  sound  level  of  LAeq  =  46,8  dB  it  is  a  very  strong  noise  source.  So  a 
customary ½” fitting must be set at a flow rate of round 50 l/min to overstep the INS in noise. 

Fig. 3 

Reference Noise Source9 

It is attached at the end of the feeding pipe like a conventional fitting. 

9 Type:  Transfer Standard 
  ID - number    PTB-IGN-0152  
  Manufacturer:  Physikalisch – Technische Bundesanstalt Braunschweig 
  Calibration date: 

14.08.2000 

142 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
                                                 
 
3. 

Dry lining walls 

The basic design of dry lining walls always consists of three elements  

- 
- 
- 

The steel frame of vertical C-profiles (conventional or slit) and horizontal U-profiles 
The acoustic-proof mineral wall inside 
The planking of gypsum board (GB) , gypsum fibreboard (GF) or OSB 

The main different static properties of the three planking materials, i.e. weight (density) and Young-
module don’t find expression in the dynamic performances. They reach roughly the same attenuation 
values of the noise sound level. 

2500 

2500 

1250 

1250 

(a) 

(b) 

Fig. 4 
Dry lining walls, conventional (a), with slit C-profiles (b) 

The pipe attached to the right side of the wall puts it in vibration. These vibrations are transmitted via 
the steel frame to the adjacent living room on the left side. The main part of the vibration is transported 
across the web of the top U-profile. Only a small part flows via the conventional C-profiles face-to-face 
(see Fig. 4(a)). Using split C-profiles (see Fig. 4(b)) only the top U-profile works as transport path. 

4. 

Wall arrangement 1 (basic wall) 

The simplest arrangement of walls in a house is a long unbroken wall. In our test case the wall was 
3,75m long and 2,5m high (WxH). It consisted of three wall modules according to the standard size of 
boards of 1,25x2,5m (WxH). The pipe was attached on one side with four clamps.  

143 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
Fig. 5 
Room arrangement 1 

(left) pipe attached 
(right) earthquake-proof wall 

4.1  Results of arrangement 1 

W1F-11  W2F-10  W3F-10  W4F-10  W5F-10  W9F-10 

Parameter 
LAeq 
INS 60.1 dB 

[dB] 
36.5 
-23.6 

[dB] 
33.8 
-26.3 

[dB] 
31 
-29.1 

[dB] 
30.6 
-29.5 

[dB] 
28.8 
-31.3 

[dB] 
31.1 
-29 

W1F-11  W2F-10  W3F-10  W4F-10  W5F-10  W9F-10 

Parameter 
LAeq 
INS 46.8 dB 

[dB] 
46.8 
0 

[dB] 
42.3 
-4.5 

[dB] 
44.6 
-2.2 

[dB] 
41.5 
-5.3 

[dB] 
47.3 
0.5 

[dB] 
44.7 
-2.1 

Table 110 
Airborne sound (upper table), fitting noise reduction (lower table) 

10 W1F-11 to W4F-10 Planking GB or GF, W5F-10 left side GB or GF, right side OSB, W9F-10 earthquake-proof 
version (Turkish Norm) 

144 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
  
 
 
                                                 
 
 
  
 
Although the guidelines deal with the reduction of fitting noise the results have also been exploited in 
relation  to  the  airborne  sound.  If  the  pipe  is  unclamped  from  the  wall,  it  doesn’t  transmit  any 
mechanical vibration to it. Nevertheless the pipe excited by the INS produces a strong airborne sound of  
60.1 dB in the room (upper table INS 60.1 dB), which is annihilated by the acoustic mineral wool inside 
the wall. 
In the first line of the tables the absolute value of the A-corrected sound level is given. In the second 
line the difference between the sound level of the INS is compiled.  
Taking in mind that humans cannot discern sound level differences below 1 dB we can comment the 
results of both tables 1 in the following manner: 

- 

- 

- 

Double planked walls always have a better performance in regard of sound reduction (airborne 
and fitting noise) than simple planked walls 
Special walls with slit C-profiles for better reduction of the airborne sound don’t work better in 
the  case  of  fitting  noise  reduction  because  the  fitting  vibrations are  transported  mainly  across 
the web of the top U-profile.  
For airborne sound reduction only a combination of one side double planked GB or GF and the 
other side OSB planked shows better results than the “specialists” for airborne reduction with 
split C-profiles (wall W5F-10, column next to last). 

4.2 

Improvement of the performance of the basic wall, silencers 

At first we call every measure suitable to improve the sound performance of a dry lining wall, which is 
not a construction element of the basic design as it has been defined in the beginning of section 3 a 
silencer. 

4.2.1  Primary silencer 

A primary silencer is a measure suitable to reduce the fitting noise acting directly on the feeding system 
without changing anything in the wall. The sound level of the fitting itself is constructional and cannot 
be modified without destroying its initial design.  
The  special  benefit  of  primary  silencers  is  based  on  their  additive  character.  Making  no  claim  to  be 
exhaustive these are: 

- 
- 
- 

complete jacketing of the feeding pipe with acoustic foam stripes of density 120 kgm-3 
sound barriers behind the fitting11 (B1,….,B4) 
sound barriers embedded in means with high internal friction 

Fig. 6 Sound barrier B1 (a), Sound barrier B1, embedded (b) 

(a) 

(b) 

11 See AFINOPRO-Advanced Plumbing Solutions 

145 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
                                                 
Table 2 shows the performance of primary silencers. Although the jacketing of the pipe with an acoustic 
foam is a simple measure it reaches the best result. The barrier B1 whose prototype has been checked in 
the lab (see Fig. 6) can be connected in series with further barriers, so that the sound level reduction of 
every barrier is added to a total performance. 

Jacketing 
Complete 
42 

Leq  [dB] 

INS 46,8 dB 

-4,8 

B1 

45.9 

-0,9 

B1+Corundum 
« ALODUR » 
42.2 

-4,6 

Table 2 
Sound level reduction by primary silencer 

4.22 Secondary silencer  

A  secondary  silencer  is  a  measure  adding  any  element  to  the  basic  wall  defined  in  section  3.  After 
different  approaches  the  application  of  some  special  layers  to  the  boards  provided  really  satisfactory 
results. Finally two kind of  materials have been found, each of them working quite differently, being 
able to reduce the noise sound level generated by the INS under 40 dB : 

- 

- 

TECOBAND 220, 80 x 1.9 mm is a product used in the car and truck body to reduce the impact 
of motor vibrations on the sound level in the cabin.  
As it can be seen in Fig. 7 the stripes of TECOBAND have been simply adhered to the panel 
inner sides of both wall sides. 

In the dry lining technology palette there is a lot of commercial tapes basing among other things 
on  closed  soft  polyethylene  foam  designed  to  be  introduced  between  metallic  member  and 
board to reduce the vibration transport between board and members. 
Stripes of that material were adhered on every C- and U-profile on both sides of the wall (see 
Fig. 8). 

Fig. 7 

Fig. 8 

            TECO Band 

                                       Closed polyethylene stripes 

TECO- 
band 

Closed  
polyethylene

LAeq  [dB] 
INS 46,8 

39.7 

-7,1 

36.2 

-10,6 

Table 3 
Sound level reduction by secondary silencers 

146 
 
  
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
  
 
 
 
5. 

Wall arrangement 2 

Fig. 9  Room arrangement 2 

In this section the first arrangement with a secondary wall perpendicularly fastened to the basic main 
wall is introduced. 
With the secondary wall a new variable comes into being, the connection between the walls. There are 
three main connections used 

- 
- 

- 

Connection A: secondary wall screwed on a C-profile of the main wall “hard” 
Connection  C:  secondary  wall  screwed  on  a  C-profile  of  the  main  wall  “soft”.  In  this  case  a 
layer of acoustic foam of 20 mm thickness has been intercalated between the two walls. 
Connection D: secondary wall screwed beside any C-profile on the main wall, hard. 

A 

D 

C 

Fig. 10 Wall connections 

147 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
In this arrangement the main wall is active in the sense of the carrier of the vibration energy and the 
secondary wall is passive. It should be expected that the secondary wall hinders the primary wall to 
vibrate totally free. Because the vibration transport face-to-face is rather weak as it has been stressed in 
section 3 the effect is negligible. 
So the wall arrangement 2 cannot have a better performance than arrangement 1. 

6. 

Wall arrangement 3 

Fig. 11 
Room arrangement 3 

The third placement 3 is exactly the opposite of the placement 2. The secondary wall is the active 
carrier of the fitting vibration and should put the basic wall in vibration by means of one of the 
connections of Fig. 10. We already know that the transmission of vibration face-to-face is rather poor 
and expect best results.  

Connection 
A    LAeq   
C    LAeq 
D    LAeq 
A  INS 46,8 dB 
C  INS 46,8 dB 
D  INS 46,8 dB 

W1F-3 
A,C,D 
[dB] 
40,6 
32,7 
35,9 
-6,2 
-14,1 
-10,9 

W2F – 3 
A,C,D 
[dB] 
32,7 
30,2 
33,3 
-14,1 
-16,6 
-13,5 

W3F – 3 
A,C,D 
[dB] 
38,6 
33 
35,3 
-8,2 
-13,8 
-11,5 

W4F – 3 
A,C,D 
[dB] 
35 
33,1 
31,9 
-11,8 
-13,7 
-14,9 

W5F-3 
A,C,D 
[dB] 
38,7 
31,7 
34,7 
-8,1 
-15,1 
-12,1 

Table 4 
Absolute values of the sound level (bold black) differences to the INS level (bold blue) 

148 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
  
 
 
 
 
 
 
Table 4 shows the absolute values of the sound level for the three different connections A, C,D as well 
as their difference to the sound level of the reference noise source the INS generating a sound level of 
46.8 dB 
At first every variant works well and reaches remarkable reductions of the sound level of the reference 
fitting. The superiority of double planked walls is again evident. The best result is attained by the wall  
W2F consisting of a conventional steel frame and a double planking GB or GF.  
The  best  connection  is  the  connection  C  (see  Fig.  10)  where  the  secondary  wall  is  screwed  to  a  C-
profile of the main wall intercalating an acoustic foam stripe between the both partners.  

In the next table the difference between the airborne sound additionally measured at every trial and the 
sound level values of table 4  “A,C,D LAeq  “ are given. 
If the airborne sound level and the fitting sound level are nearly equal this means that the connection 
doesn’t transmit the vibration of the pipe to the adjacent room. 

W1F-3  W2F – 3  W3F – 3  W4F – 3  W5F-3 
[dB] 

[dB] 

[dB] 

[dB] 

[dB] 

A,C,D 

A 

C 

D 

8,6 

0,3 

3,7 

1,1 

8,2 

0,7 

-0,1 

0,3 

-0,2 

0,7 

6,4 

1,9 

2,2 

0,6 

5,6 

Table 5 
Vibration sound level transported by the connections A,C,D, i.e. difference between 
the fitting noise and airborne sound 

The squares highlighted in green signalise that no vibration energy is transported to the supposed living 
room  in  Fig.  11.  The  “soft”  connection  on  C-profiles  of  the  main  wall  guarantees  a  zero  transport  of 
vibration energy for all the wall variants measured, inclusive the single planked walls.  

In  absolute  values  only  the  wall  W2F-3  with  connection  C  reaches  the  value  of  30  dB  without 
supplementary silencer solutions (see table 4).  

7. 

Conclusions 

The guidelines as a distillate of the project granted by the European Union 

“Analysis of fitting noise propagation in steel lightweight constructions and design solutions for their 
prevention”  

offer practice solutions for the reduction of fitting sound. 

A reference Installation Noise Standard (INS) was used generating a noise level of 46.8 dB to be able to 
generalise the results. 
The target of the reduction of the INS sound level down to 30 dB has been reached for some solutions. 
This means that  a performance of –16.8 dB for the best solutions has been obtained. 

149 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
Usually  a  non-classified  commercial  fitting  produces  a  noise  level  lower  than  that  of  the  INS  and 
therefore the proposed solutions work well in every case. 
Of  course  it  makes  no  sense  to  save  money  purchasing  the  worst  fittings  but  spending  it  again  for 
measures for the improvement of the sound transmission of the walls. 
So non-classified fittings should generate maximum noise levels between 36 to 40 dB at a water flow of 
35 l/min. 
Such flows are only sensible for filling a bath tub anyhow. 
So in the day-to-day matters noise reduction far below 30 dB will be reached.   

The last table compiles all the results obtained to have help for decisions.  

Walls 
LAeqINS 
INS 46,8 dB 
P. silencer 
Total 
W2F-10 
+ secondary 
silencer 

LAeq  [dB] 
INS 46,8 
P. silencer 
Total 
Walls 

LAeqINS 
INS 46,8 dB 
P. silencer 
Total 
Walls 

LAeqINS 
INS 46,8 dB 

P. silencer 
Total 
Walls 

LAeqINS 
INS 46,8 dB 

P. silencer 
Total 

W3F-10  W4F-10  W5F-10 
41,5 

44,6 

47,3 

-2,2 
-4,6 
-6,8 

-5,3 
-4,6 
-9,9 

0,5 
-4,6 
-4,1 

W1F-10  W2F-10 

46,8 

0 
-4,6 
-4,6 

42,3 

-4,5 
-4,6 
-9,1 

W2F_50_3
Tecoband 

W2F_80_3
closed 
polyethylene

39,7 

-7,1 
-4,6 
-11,65 

36,2 

-10,6 
-4,6 
-15,15 

W1F-3A  W2F – 3A 

W3F – 3A  W4F – 3A  W5F-3A 

40,6 

-6,2 
-4,6 
-10,8 

32,7 

-14,1 
-4,6 
-18,7 

W1F - 3C  W2F – 3C 

32,7 

-14,1 
-4,6 
-18,65 

30,2 

-16,6 
-4,6 
-21,15 

W1F-3D  W2F-3D 

35,9 

-10,9 
-4,6 
-15,45 

33,3 

-13,5 
-4,6 
-18,05 

38,6 

35 

38,7 

-8,2 
-4,6 
-12,8 

-11,8 
-4,6 
-16,4 
W3F – 3C  W4F – 3C  W5F-3C 

-8,1 
-4,6 
-12,7 

33 

33,1 

31,7 

-13,8 
-4,6 
-18,35 

-13,7 
-4,6 
-18,25 
W3F-3D-u W4F-3D  W5F-3D 

-15,1 
-4,6 
-19,65 

35,3 

-11,5 
-4,6 
-16,05 

31,9 

-14,9 
-4,6 
-19,45 

34,7 

-12,1 
-4,6 
-16,65 

Table 6 
All results 

150 
 
 
 
 
 
 
 
 
 
  
 
 
  
  
  
 
  
  
  
 
  
  
  
 
  
  
  
 
  
  
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
The first line of a section is always the absolute value for the sound level obtained with the reference 
noise source of 46.8 dB (INS) 

The second line is the difference between the sound level reached and the sound level of the noise as the 
absolute performance of the arrangement. 

The third line contains the sound reduction power of the best primary silencer. Because the performance 
of the primary silencer (P. silencer) is added to that of the wall, the total possible reduction of the sound 
level is given in the last line of the section.  

The  performance  of  the  arrangement  2  has  been  left  out  because  it  is  similar  to  that  of  the  wall 
arrangement 1. 

If the reduction power of the wall alone reaches values of –10 dB and better a primary silencer should 
not be necessary. 

151 
 
 
 
 
 
 
 
 
European Commission

EUR 26011 —  Analysis of fitting noise propagation in lightweight steel constructions and design 

solutions for their prevention (AFINOPRO)

Luxembourg: Publications Office of the European Union

2013 — 152 pp. — 21 × 29.7 cm

ISBN 978-92-79-30790-4
doi:10.2777/17298