Bsi bs en 12354 5 2009 (2011)

EN 12354-1:2000, Building acoustics  Estimation of acoustic performance of buildings from the performance of elements  Part 1: Airborne sound insulation between rooms EN 12354-2, Bui

A list of organizations represented on this committee can be obtained

on request to its secretary

This publication does not purport to include all the necessary provisions of a contract Users are responsible for its correct application

Compliance with a British Standard cannot confer immunity from legal obligations.

This British Standard

was published under the

authority of the Standards

Policy and Strategy

EUROPÄISCHE NORM

ICS 91.120.20

English Version

Building acoustics - Estimation of acoustic performance of building from the performance of elements - Part 5: Sounds

levels due to the service equipment

Acoustique du bâtiment - Calcul des performances

acoustiques des bâtiments à partir des performances des

éléments - Partie 5 : Niveaux sonores dûs aux équipements

de bâtiment

Bauakustik - Berechnung der akustischen Eigenschaften von Gebäuden aus den Bauteileigenschaften - Teil 5:

Installationsgeräusche

This European Standard was approved by CEN on 5 March 2009.

CEN members are bound to comply with the CEN/CENELEC Internal Regulations which stipulate the conditions for giving this European Standard the status of a national standard without any alteration Up-to-date lists and bibliographical references concerning such national standards may be obtained on application to the CEN Management Centre or to any CEN member.

This European Standard exists in three official versions (English, French, German) A version in any other language made by translation under the responsibility of a CEN member into its own language and notified to the CEN Management Centre has the same status as the official versions.

CEN members are the national standards bodies of Austria, Belgium, Bulgaria, Cyprus, Czech Republic, Denmark, Estonia, Finland, France, Germany, Greece, Hungary, Iceland, Ireland, Italy, Latvia, Lithuania, Luxembourg, Malta, Netherlands, Norway, Poland, Portugal, Romania, Slovakia, Slovenia, Spain, Sweden, Switzerland and United Kingdom.

EUROPEAN COMMITTEE FOR STANDARDIZATION

C O M I T É E U R O P É E N D E N O R M A L I S A T I O N

E U R O P Ä I S C H E S K O M I T E E F Ü R N O R M U N G

Management Centre: Avenue Marnix 17, B-1000 Brussels

© CEN All rights of exploitation in any form and by any means reserved

worldwide for CEN national Members.

Ref No EN 12354-5:2009: E

Incorporating corrigendum October 2010

2010

Contents

Foreword 4

Introduction 5

1 Scope .6

2 Normative references .6

3 Relevant quantities .7

3.1 Quantities to express building performance 7

3.2 Quantities to express product performance 9

4 Calculation models .9

4.1 General principles 9

4.2 Airborne sound transmission through pipes and ducts 10

4.2.1 General 10

4.2.2 Sources 13

4.2.3 Transmission 15

4.3 Airborne sound transmission through building construction 17

4.3.1 General 17

4.3.2 Sources 18

4.3.3 Transmission in a source room 18

4.3.4 Transmission through a building 19

4.4 Structure-borne transmission through building construction 19

4.4.1 General 19

4.4.2 Sources 21

4.4.3 Transmission through the mounting 21

4.4.4 Transmission through the building 22

5 Application of models 23

5.1 Application to ventilation systems 23

5.1.1 General 23

5.1.2 Guidelines for the application 24

5.2 Application to heating installations 25

5.2.1 General 25

5.2.2 Guidelines 26

5.3 Application to lift installations 26

5.3.1 General 26

5.3.2 Guidelines 26

5.4 Application to water supply installations 27

5.4.1 General 27

5.4.2 Guidelines 30

5.5 Application to waste water installations 32

5.5.1 General 32

5.5.2 Guidelines for the application 33

5.6 Application to miscellaneous service equipment 33

5.6.1 General 33

5.6.2 Guidelines 33

6 Accuracy 34

Annex A (normative) List of symbols 35

Annex B (informative) Airborne sound sources in duct systems 38

B.1 Sound power level of fans 38

B.2 Sound power level of flow-generated sound 38

Annex C (informative) Airborne sound sources 39

C.1 Sound sources 39

C.1.1 Service equipment, such as whirlpool baths 39

C.1.2 Waste water appliances 39

C.1.3 Heating systems 39

C.2 Sound transmission in source room 39

Annex D (informative) Structure-borne sound sources 41

D.1 Measurement of characteristic structure-borne sound power level 41

D.1.1 General 41

D.1.2 Service equipment with high source mobility 42

D.1.3 Service equipment with known source mobility 46

D.1.4 Service equipment with low source mobility 47

D.2 Mounting with elastic supports 48

D.3 Estimation of data on source strength, elastic supports and source mobilities 49

Annex E (informative) Sound transmission through elements of duct and pipe systems 50

E.1 Introduction 50

E.2 Duct wall 50

E.3 Along straight, unlined duct 51

E.4 Along straight, lined duct / silencer 51

E.5 Area changes 52

E.6 Branches 52

E.7 Air terminal devices and openings 52

E.8 Radiation by openings 53

Annex F (informative) Sound transmission in buildings 55

F.1 Transmission through junctions 55

F.2 Adjustment term 56

F.3 Mobility of supporting building elements 57

F.3.1 Essentially homogeneous elements 57

F.3.2 Elements with beams 57

F.3.3 Excitation near borders and corner 58

F.4 Measurement of total transmission 58

F.4.1 Airborne sound transmission 58

F.4.2 Structure-borne sound transmission 59

Annex G (informative) Sound levels at low frequencies 61

Annex H (informative) Guidance for the design of service equipment systems 63

H.1 General 63

H.2 Choice of equipment 63

H.3 Location of a service equipment room and air-handling unit 63

H.4 Airborne sound insulation of service equipment room 64

H.5 Structure borne sound and vibration insulation 64

H.5.1 Heavy structure 64

H.5.2 Lightweight structure 64

H.6 Pipes and ductwork 65

Annex I (informative) Calculation examples 66

I.1 Example for a ventilation system 66

I.2 Example for a whirlpool bath 68

I.3 Example for a sanitary system 71

Bibliography 73

Attention is drawn to the possibility that some of the elements of this document may be the subject of patent rights CEN [and/or CENELEC] shall not be held responsible for identifying any or all such patent rights This document is the first version of a standard, which forms a part of a series of standards specifying calculation models in building acoustics:

 Part 1: Building Acoustics  Estimation of acoustic performance of buildings from the performance of elements  Part 1: Airborne sound insulation between rooms

 Part 2: Building Acoustics  Estimation of acoustic performance of buildings from the performance of elements  Part 2: Impact sound insulation between rooms

 Part 3: Building Acoustics  Estimation of acoustic performance of buildings from the performance of elements  Part 3: Airborne sound insulation against outdoor sound

 Part 4: Building Acoustics  Estimation of acoustic performance of buildings from the performance of elements  Part 4: Transmission of indoor sound to the outside

 Part 5: Building Acoustics  Estimation of acoustic performance of buildings from the performance of elements  Part 5: Sound levels due to the service equipment

 Part 6: Building Acoustics  Estimation of acoustic performance of buildings from the performance of elements  Part 6: Sound absorption in enclosed spaces

Although this part covers the most common types of service equipment and installations in buildings, it cannot

as yet cover all types and all situations It sets out an approach for gaining experience for future improvements and developments

The accuracy of this standard can only be specified in detail after widespread comparisons with field data, which can only be gathered over a period of time after establishing the prediction model To help the user in the mean time, indications of the accuracy have been given, based on earlier comparisons with comparable prediction models It is the responsibility of the user (i.e a person, an organisation, the authorities) to address the consequences of the accuracy, inherent for all measurement and prediction methods, by specifying requirements for the input data and/or applying a safety margin to the results or applying some other correction

Annex A forms an integral part of this part of EN 12354 Annexes B, C, D, E, F, G and H are for information only

According to the CEN/CENELEC Internal Regulations, the national standards organizations of the following countries are bound to implement this European Standard: Austria, Belgium, Bulgaria, Cyprus, Czech Republic, Denmark, Estonia, Finland, France, Germany, Greece, Hungary, Iceland, Ireland, Italy, Latvia, Lithuania, Luxembourg, Malta, Netherlands, Norway, Poland, Portugal, Romania, Slovakia, Slovenia, Spain, Sweden, Switzerland and the United Kingdom

Introduction

The estimation of sound levels due to service equipment in buildings is a complex task and structure-borne sources and transmission are not completely understood In addition there are large variations between different equipment and installations and an installation often results in both airborne and structure-borne sources This document contains a framework within which this subject can be treated The main part (Clause 4) describes general models for sound transmission and related sources for ducts, airborne sound through buildings and structure-borne sound through buildings For airborne and structure-borne sound transmission, parts 1 and 2 of EN 12354 are used wherever possible

In Clause 5 the application of these models to the different types of service equipment in buildings is addressed, specifying what is already known and available and what is not Informative annexes give additional information on various aspects, related to sources and their sound production as well as to specific aspects of sound transmission through buildings Wherever possible references are made to available handbooks, literature or ongoing standardization work Over the course of time some annexes or parts of them, especially those relating to the sound production by sources, can be deleted when appropriate standards become available

For sound transmission through ducts there are standardized methods available to determine the sound power level of sources or the transmission loss of elements Various handbooks are widely used for these estimations

For airborne sound transmission through buildings information exists about sources and transmission, but some aspects that are particularly relevant to service equipment are less well known, such as the effect of acoustic near-fields, non-diffuse spaces and excitation and transmission at low frequencies For these aspects some indications are given as to how they could be treated and also as an indicator for the direction of further research and future improvements to the models

For structure-borne sound transmission similar solutions and problems exist as used for airborne sound However, here the appropriate methods to characterize the sources for structure-borne sound excitation are just starting to become available, largely due to standardization work started within CEN (TC126/WG7) Therefore in this document a choice has been made to use a general quantity in the models, called "the characteristic structure-borne sound power level" of sources, even though there is no practical measurement method available at the moment This allows the estimation models to have a general form that could be developed and refined in the future For some types of equipment indications are given in an informative annex as to how this quantity can be deduced or estimated from available and current measurement methods, such as the ones already developed within CEN

The aim of this document is to provide a general basis for a practical approach to the estimation of sound levels due to service equipment It also clarifies the need for work on source characterisation with an indication of areas where further research work is needed

1 Scope

This document describes calculation models to estimate the sound pressure level in buildings due to service equipment As for the field measurement document (EN ISO 16032) it covers sanitary installations, mechanical ventilation, heating and cooling, service equipment, lifts, rubbish chutes, boilers, blowers, pumps and other auxiliary service equipment, and motor driven car park doors, but can also be applied to others equipment attached to or installed in buildings The estimation is primarily based on measured data that characterises both the sources and the building constructions The models given are applicable to calculations

in frequency bands

This document describes the principles of the calculation models, lists the relevant quantities and defines its applications and restrictions It is intended for acoustical experts and provides the framework for the development of application documents and tools for other users in the field of building construction, taking into account local circumstances

The calculation models described use the most general approach for engineering purposes, with a link to measurable quantities that specify the performance of building elements and equipment The known limitations of these calculation models are described in this document Users should, however, be aware that other calculation models also exist, each with their own applicability and restrictions

The models are based on experience with predictions for dwellings and offices; they could also be used for other types of buildings provided the constructional dimensions are similar to those in dwellings

The following referenced documents are indispensable for the application of this document For dated references, only the edition cited applies For undated references, the latest edition of the referenced document (including any amendments) applies

EN 12354-1:2000, Building acoustics  Estimation of acoustic performance of buildings from the performance

of elements  Part 1: Airborne sound insulation between rooms

EN 12354-2, Building acoustics  Estimation of acoustic performance of buildings from the performance of elements  Part 2: Impact sound insulation between rooms

EN 13141-1, Ventilation for buildings  Performance testing of components/products for residential ventilation

 Part 1: Externally and internally mounted air transfer devices

EN 13141-2, Ventilation for buildings  Performance testing of components/products for residential ventilation

 Part 2: Exhaust and supply air terminal devices

EN ISO 3740, Acoustics  Determination of sound power levels of noise sources  Guidelines for the use of basic standards (ISO 3740:2000)

EN ISO 3741, Acoustics  Determination of sound power levels of noise sources using sound pressure 

Precision methods for reverberation rooms (ISO 3741:1999)

EN ISO 3743 (all parts), Acoustics  Determination of sound power levels of noise sources  Engineering methods for small, movable sources in reverberant fields (ISO 3743-1:1995 and ISO 3743-2:1996)

EN ISO 3744, Acoustics  Determination of sound power levels of noise sources using sound pressure 

Engineering method in an essentially free field over a reflecting plane (ISO 3744:1994)

EN ISO 3745, Acoustics  Determination of sound power levels of noise sources using sound pressure 

Precision methods for anechoic and semi-anechoic rooms (ISO 3745:2003)

EN ISO 3746, Acoustics  Determination of sound power levels of noise sources using sound pressure 

Survey method using an enveloping measurement surface over a reflecting plane (ISO 3746:1995)

EN ISO 3747, Acoustics  Determination of sound power levels of noise sources using sound pressure 

Comparison method for use in situ (ISO 3747:2000)

EN ISO 3822-1, Acoustics  Laboratory tests on noise emission from appliances and equipment used in water supply installations  Part 1: Method of measurement (ISO 3822-1:1999)

EN ISO 3822-2, Acoustics  Laboratory tests on noise emission from appliances and equipment used in water supply installations  Part 2: Mounting and operating conditions for draw-off taps and mixing valves (ISO 3822-2:1995)

EN ISO 3822-3, Acoustics  Laboratory tests on noise emission from appliances and equipment used in water supply installations  Part 3: Mounting and operating conditions for in-line valves and appliances

EN ISO 3822-4, Acoustics  Laboratory tests on noise emission from appliances and equipment used in water supply installations  Part 4: Mounting and operating conditions for special appliances

EN ISO 7235, Acoustics  Laboratory measurement procedure for ducted silencers and air-terminal units 

Insertion loss, flow noise and total pressure loss (ISO 7235:2003)

EN ISO 10846-1, Acoustics and vibration  Laboratory measurement of vibro-acoustic transfer properties of resilient elements  Part 1: Principles and guidelines (ISO 10846-1:2008)

EN ISO 10846-2, Acoustics and vibration  Laboratory measurement of vibro-acoustic transfer properties of resilient elements  Part 2: Direct method for determination of the dynamic stiffness of resilient supports for translatory motion (ISO 10846-2:2008)

EN ISO 10846-3, Acoustics and vibration  Laboratory measurement of vibro-acoustic transfer properties of resilient elements  Part 3: Indirect method for determination of the dynamic stiffness of resilient supports for translatory motion (ISO 10846-3:2002)

EN ISO 10846-4, Acoustics and vibration  Laboratory measurement of vibro-acoustic transfer properties of resilient elements  Part 4: Dynamic stiffness of elements other than resilient supports for translatory motion (ISO 10846-4:2003)

EN ISO 11691, Acoustics  Measurement of insertion loss of ducted silencers without flow  Laboratory survey method (ISO 11691:1995)

3 Relevant quantities

3.1 Quantities to express building performance

The protection against sound from equipment and machinery according to EN ISO 16032 can be expressed in sound pressure levels in various ways These quantities are determined in octave bands as maximum level using time weighting "S" or time weighting "F" or as equivalent level; in all cases normalization to a reference equivalent absorption area or standardization to a reference reverberation time can be applied The building performance is normally expressed in an A-weighted or C-weighted sound pressure level that is to be calculated from these octave band levels

NOTE The octave band levels are also used to determine the so-called NC, NR or RC ratings, as described in many textbooks This is especially the case for buildings such as offices, commercial buildings, schools and performance spaces

3.1.1 A-weighted maximum sound pressure level LA max, The A-weighted maximum sound pressure level in a room, due to the sound produced by equipment or machinery in the building

NOTE This sound pressure level is obtained from the maximum sound pressure level in octave bands from 63 Hz to

8 kHz using time weighting "S" (LAS max) or time weighting "F" (LAF max) The sound pressure levels in octave bands can

also be normalized (LAS max, n, LAF max, n) or standardized (LAS max, nT, LAF max,nT)

3.1.2 A-weighted equivalent continuous sound pressure level LAeq The equivalent A-weighted sound pressure level in a room, due to the sound produced by equipment or machinery in the building

NOTE This sound pressure level is obtained from the equivalent sound pressure level in octave bands from 63 Hz to

8 kHz The sound pressure levels in octave bands can also be normalized (LAeq, n) or standardized (LAeq, nT)

3.1.3 C-weighted maximum sound pressure level LC max, The C-weighted maximum sound pressure level in a room, due to the sound produced by equipment or machinery in the building

NOTE This sound pressure level is obtained from the maximum sound pressure level in octave bands from 31,5 Hz

to 8 kHz using time weighting "S" (LCS max) or time weighting "F" (LCF max) The sound pressure levels in octave bands can

also be normalized (LCS max, n, LCF max, n) or standardized (LCS max, nT, LCF max, nT)

3.1.4 C-weighted equivalent sound pressure level LCeq The equivalent C-weighted sound pressure level in a room, due to the sound produced by equipment or machinery in the building

NOTE This sound pressure level is obtained from the equivalent sound pressure level in octave bands from 31,5 Hz

to 8 kHz The sound pressure levels in octave bands can also be normalized (LCeq, n) or standardized (LCeq, nT).

3.1.5 Relation between quantities

The A-weighted and C-weighted quantities are all obtained from the sound pressure levels in octave bands

These sound pressure levels (L) are depending on the applied time weighting, i.e "S", "F" or integration over a

cycle (equivalent) The level with these various time weightings depends on the type of sound and cannot be deduced from each other in general Hence, the estimated octave band level will have to relate to the same time weighting as the specified quantity

In all cases there is a direct relation between the sound pressure level (L), the normalized sound pressure level (Ln) and the standardized sound pressure level (LnT) in octave bands These relations are given by:

dBlg

10 ref

n

A

A L

dB16,0lg

10 ref refn

nT

V

T A L

where

A is the equivalent absorption area in the room, in square metres;

Aref is the reference equivalent absorption area (Aref = 10 m2), in square metre;

Tref is the reference reverberation time (Tref = 0,5 s), in seconds;

V is the volume of the room, in cubic metres

In this document the normalized sound pressure level Ln in octave bands, with the appropriate average and time weighting, is chosen as the prime quantity to predict The other quantities can be obtained from this directly

3.2 Quantities to express product performance

The quantities to express the performance of products relate on the one hand to the sources of sound and on the other hand to the transmission of sound In general this concerns both airborne and structure-borne sound

The relevant sound sources differ for the various equipment and installations considered Therefore the relevant quantities to express the performance of sound sources will be dealt with in the appropriate sections However, the quantities for the sources must in all cases relate to the same time weighting as the quantity to

be estimated for the building performance

The relevant elements in sound transmission are partly those from other documents in this series, such as

EN 12354-1 and EN 12354-2 where the related quantities are specified, and partly specific to the service equipment under consideration Therefore the relevant quantities will also be indicated in the appropriate clauses

4.1 General principles

In general a mixture of airborne and structure-borne sound transmission results in the sound level in a room due to service equipment Which of those is dominant depends on the type of equipment and installation as well as on the type of building construction Furthermore, service equipment and installations often consist of several sound sources and several connection points between the installation and the building structure This makes a general prediction method rather complicated

NOTE An additional problem is that there are only a few well-established measurement methods to quantify the strength of the equipment Especially in the field of structure-borne sound these methods, and the quantities, have been missing, though now work has started in CEN/TC126/WG7 Indications are given in Annexes B, C and D

It is assumed that a complete installation can be divided into several of airborne and/or structure-borne sound sources that can be considered independently from each other Such a source can be a physical object, a partial source or a combination of various partial sources or connection points, depending on the type of equipment or installation considered The model approach is to consider one such source at the time and apply a one-dimensional model, choosing the most relevant model for the type of source The resulting sound pressure level in a room follows from the addition of the contribution of each of such sources being considered

In general three different transmission situations are considered:

 airborne sound transmission through pipes and/or ducts;

 airborne sound transmission through a building construction;

 structure-borne sound transmission through a building construction

For each of these situations a general approach is described in the next subclause of this clause For several types of service equipment and installations, the most appropriate applications of these general models will be specified in Clause 5

The resulting normalized sound pressure level in a room in octave bands, Ln, follows from the addition of the

transmitted sound from all relevant sources and transmission situations for the considered installation or

L L

L

1 k

10 / 1

j

10 / m

1 i

10 / n

k s, n, j

a, n, i

10 lg

Ln,a,j is the normalized sound pressure level due to airborne sound transmission through the building

structure for source j, in decibels;

Ln,s,k is the normalized sound pressure level due to structure-borne sound transmission through the

building structure for source k, in decibels;

m is the number of sound sources related to duct transmission;

n is the number of airborne sound sources;

o is the number of structure-borne sound sources

When the building performance is to be expressed as the maximum level, especially with time weighting "F",

the results from Equation 2 can be considered as an estimate of the upper limit An estimate of the lower limit

would than be the maximum value of all the sources considered separately

The models can be used to calculate the building performance in octave bands, based on acoustic data for

the sound sources and building elements in octave bands The calculations are to be performed for the octave

bands from 63 Hz to 4000 Hz, unless a more limited range is sufficient for the type of equipment being

considered From these the single number rating for the building performance (A- or C-weighting) can be

deduced as for the measurement results in accordance with EN ISO 16032

NOTE The calculations can be extended to higher or lower frequencies if acoustic data are available for such a larger

frequency range However, especially at the lower frequencies no information is currently available on the accuracy of

such calculations (see also Annex G)

The models assume a diffuse sound field in the receiving room Though often a sufficiently realistic

assumption, large deviations may occur at low frequencies Since sound from some service equipment will be

dominated by low frequencies, such deviations cannot be neglected Special attention will be given to this

aspect for the application of the models to specific service equipment and installations General information on

this aspect is given in Annex G

4.2 Airborne sound transmission through pipes and ducts

4.2.1 General

Each element of a duct system can be a transmission element as well as a sound source In the predictions

each sound source is considered separately and the sources and elements are considered to be independent,

thus interference between elements, modal effects and resonances are neglected

The normal quantity to express the source strength is the airborne sound power level LW, injected into the duct The sound transmission through the duct is described by the sound power level reduction ∆LWoccurring

in each distinguishable element of the duct The resulting sound pressure in a receiving room is either caused

by sound radiating at the duct opening (room a) or by sound radiating by the duct itself (room b) The resulting

sound pressure level depends on the absorption in that room, which is normalized to Aref= 10 m2

The resulting normalized sound pressure level in a room, Ln,d, due to a sound source in a duct follows from:

dB4lg10

∆1

W,i W

L

where

LW is the sound power level of the source, in decibels;

∆LW,i is the sound power level reduction by element i, in decibels;

e is the number of elements between source and receiving room;

Aref is the reference absorption area (= 10 m2), in square metres

NOTE 1 This relation assumes a diffuse sound field in the room However, that is often not the case In EN 12354-6

indications are given of the effect of non-diffuse spaces on the resulting sound levels These indications can be used to

correct the estimation of the sound pressure level in the room

NOTE 2 If the room average is not of interest but the sound pressure level at a specific position in the room, this level

may be influenced or even dominated by the direct sound of the sound-radiating element in the room For a position at

distance r of that element with a directivity factor Q, the last term in Equation (3a) could be replaced by:

4 2

Q

The radiated sound power into a room is influenced by the position of the radiating element in the room (last

element in the chain, i = e) with respect to its boundaries This effect shall be included in the sound power

level reduction of that last element For some elements this is already included through the measurement

method applied, but if that is not the case it shall be added to the sound power level reduction of the radiating

element; see Annex E

Figure — 1 System of a pipe with a sound source, transmission elements and receiving rooms (a and b)

ˆ

‰

If the source considered is the sound field in a room, the performance of the duct system can also be

expressed as the normalized level difference of the transmission system Dn,s as treated in EN 12354-1 This

level difference follows from:

W, s

S

A L

where

Dn,s is the normalized sound level difference for indirect transmission through a system s, in decibels;

S1 is the area of the first element (i=1) of the transmission system in the source room, i.e an

opening, duct section or air terminal device, in square metres

NOTE For air transfer devices or a pair of air terminal devices with a simple ventilation systems for dwellings, this

quantity is also directly measured and expressed as the Dn,e , see EN 13141-1 and EN 13141-2 Equation (4) could than

be used also to deduce the sound power level reduction for such (combination of) elements

4.2.2 Sources

The sources can be elements of the system which produce sound themselves, such as an air moving device

or a burner, sound created at or by elements of the system, such as flow-generated sound from grids, bends

and silencers or sound injected into the duct from outside

In all cases the strength of these airborne sound sources will be given by the sound power level LW, as it is

propagating into the duct in one direction or as it is radiated directly into the surrounding space The sound

power level should relate to the appropriate operating conditions of the system under consideration The

sound power level of sources is primarily based on the results of standardized measurement methods

4.2.2.1 Air moving device

For a ducted air moving device we normally distinguish between the inlet sound power level, LW,in, outlet

sound power level, LW,out, and unit sound power level, LW,unit, in which "inlet" and "outlet" refer to the flow

direction and 'unit' to the radiated structure-borne sound by the device itself The sound power level of these

sources is primarily based on standardized measurements; see also Annex B

4.2.2.2 Flow-generated sound

For sources such as flow-generated sound from grids, bends, flow rate controllers, fire dampers,

multi-leaf-dampers and silencers the sound power level can be determined directly by measurements Estimations can

be deduced from empirical relationship, see Annex B

4.2.2.3 Sound entering through openings and devices

For sources such as the sound entering a duct from the outside through a duct opening, inlet or outlet devices,

the sound power level can be determined indirectly from the measured transmission loss of that opening or

device The sound power level for transmission into the duct, LW, follows from the transmission loss Dt,oi of

the device from outside to inside (see 4.2.3) as:

dB4lg

oi t, o

D L

where

Dt,oi is the sound power transmission loss for a duct opening or device for transmission from outside to

inside, in decibels;

Lo is the sound pressure level in the source room, in decibels;

Sco is the area of the cross section of the duct opening, in square metres

NOTE The transmission loss of the opening device can be based on direct measurements Since there is by

definition a relation between the transmission loss of an air-terminal device, i.e an opening, from outside to inside the duct

and vice versa, the one can be deduced also from the other; see Annex E

Since this sound transmission is also influenced by the position of the opening or device with respect to the

room boundaries, this effect shall be included in the sound power transmission loss of the element being

considered For some elements this is already included through the applied measurement method, but if that

is not the case it shall be added to the sound power transmission loss of the element being considered; see

Annex E

4.2.2.4 Sound entering through duct wall

For sources such as sound entering the duct from outside (breaking in), the sound power level can be

determined indirectly from the measured transmission loss of the duct The sound power level for transmission

up or downstream the duct, LW, follows from the sound reduction index Roi (transmission loss from outside to

inside) of the duct as:

dBlg

106lg10

dBlg

106lg10

d cd,

d cd, u cd, d

oi o

d

W,

u cd,

d cd, u cd, d

oi o

u

W,

S

S S S

R L

L

S

S S S

R L

L

+

−

−+

−

=

(6)

where

Lo is the sound pressure level in the room outside the duct, in decibels;

Roi is the sound reduction index of the duct for transmission from outside to inside, in decibels;

Sd is the exposed area of the duct in the room, in square metres;

Scd,d is the area of the cross section of the duct at the downstream end of the exposed part of the duct,

in square metres;

Scd,u is the area of the cross section of the duct at the upstream end of the exposed part of the duct, in

square metres

NOTE 1 The sound field outside the duct is assumed to be diffuse while inside a plane sound wave is considered

NOTE 2 This sound reduction index Roi can be based on direct measurements, but can also be deduced from the

sound reduction index Rio as measured and defined for the opposite transmission direction, i.e from inside to outside; see

Annex E

For several sources also general rules can be applied for an estimation of the sound power levels Information

on this is given in Annex B

4.2.3 Transmission

In a transmission system various elements will cause a reduction of the sound power level during propagation, such as straight ducts, internal absorbing linings, bends, restrictions, junctions, silencers and transmission through openings, grids or duct walls The level reduction is either directly expressed as a sound power level reduction ∆L'W per unit or unit length ∆L'W or in a related quantity like the sound reduction index of a duct from

inside to outside, Rio, the insertion loss of a silencer, Di, or the transmission loss of a device, Dt

For application in the calculation according to Equation (3a), the following relations can be used within the limits of application for the various elements as indicated in the appropriate measurement standards

4.2.3.1 Elements as unit

where

∆LW,unit is the sound power level reduction per unit of the element, in decibels

4.2.3.2 Elements with reduction per unit length

where

∆L'W is the sound power level reduction per unit length of the element, in decibels per metre;

l is the actual length of the element, as measured along the centre line of the duct, in metres

4.2.3.3 Elements in the duct with given insertion loss

where

Di is the insertion loss as determined for a silencer in accordance with EN ISO 7235 or

EN ISO 11691, for an air transfer device in accordance with EN 13141-1 or for other elements in

a comparable way, in decibels

NOTE For silencers the insertion loss determined in this way can be considered as a good estimate of the transmission loss of the element.

4.2.3.4 Elements at duct end with given insertion loss

where

Di is the insertion loss as determined for an air terminal device in accordance with EN 13141-2,

in decibels

Di,io is the transmission loss of the open end of the test object in accordance with EN ISO 7235

(see Annex E), in decibels

4.2.3.5 Elements with given transmission loss

where

Dt is the transmission loss as determined for an air terminal unit in accordance with EN ISO 7235 or

in a comparable way for other elements, in decibels

NOTE The transmission loss for air-terminal units according to this standard includes, as it should, the transmission

loss of the open end The transmission loss of the open end depends on the position of the opening relative to reflecting

surfaces, i.e an opening in the room centre, in a wall or near a corner

4.2.3.6 Elements with given sound reduction index

dB4

Ωlg103lg

10

∆

d

d c, io

S R

where

Rio is the sound reduction index of the duct for transmission from inside to outside, in decibels;

Ω is the angle around the duct into which radiation occurs, in radians (room centre: Ω = 4π, near wall:

Ω = 2π, near edge: Ω = π)

NOTE 1 This relationship assumes that only half of the sound power inside the duct is involved in the transmission to

the outside

NOTE 2 This sound reduction index Rio can be based on direct measurements, but can also be deduced from the

sound reduction index Rio as measured and defined for the opposite transmission direction, i.e from outside to inside; see

Annex E

4.2.3.7 Radiating element into a room

For an element that radiates sound power into a room the effect of its position in the room with respect to its

boundaries shall be included in the sound power level reduction of that last element If this is not the case for

the measurement data available, that effect shall be added:

where

∆LW,element is the sound power level reduction of the radiating element without the influence of the

room position, in decibels

DΩ is the solid angle directivity index, in decibels

For several elements also general rules can be applied for an estimation of the transmission reduction

Information on this is given in Annex E

4.3 Airborne sound transmission through building construction

4.3.1 General

The basic quantity to express the source strength is the airborne sound power level LW The resulting sound

pressure level in the source room depends mainly on the absorption in that room Asource However, the room

shape will also influence the actual excitation of the structures, the distance between source and structures

and the radiation pattern of the source The transmission from source room to receiving room normally

involves the transmission via various transmission paths between elements (i) of the source room and

elements (j) of the receiving room This transmission can be described by the flanking sound reduction index

for that transmission path Rij

The resulting normalized sound pressure level in a room, Ln,a, for one sound source follows from:

dB10

lg

10

m,n

1 j 1 i

10 / L a

Ln,a,ij is the normalized sound pressure level in the receiving room due to an airborne sound source in

the source room, as caused by sound transmission from an excited element i in the source room

and a radiating element j in the receiving room, in decibels;

m is the number of elements i in the source room participating in the sound transmission;

n is the number of elements j in the receiving room participating in the sound transmission

The normalized sound pressure level in the receiving room for each transmission path i, j, Ln,a,ij, follows from

the sound power level of the source (LW), the transmission to the resulting sound pressure in the source room

near element i (Ds,i) and the transmission through the building to the receiving room via the path considered ij

(Rij,ref); see Figure 2

dB4lg10lg

ref

i ref

ij, i s, W

D L

where

LW is the sound power level of the source, in decibels;

Figure — Airborne sound transmission from a source through a building via a transmission path ij 2

ˆ

‰

Ds,i is the sound transmission to element i in the source room, in decibels;

Rij,ref is the flanking sound reduction index for transmission from element i in the source room to

element j in the receiving room, with reference to the area Sref = 10 m2, in decibels;

Si is the area of the excited element i in the source room, in square metres;

Aref is the reference equivalent absorption area, in square metres, Aref = 10 m2

NOTE 1 The definition assumes that the reference values for pressure and power are such that ρocoWref/pref2 =1 This

is the case with ISO-reference values and ρoco = 400 Ns/m 3

NOTE 2 The normalized sound pressure level in the source room, at sufficient distance from the source is estimated as

Ln,a = Lw – 4

The quantity Ds,i should include the effects of:

 the room shape and sound field distribution;

 specific radiation effects of the source (directivity);

 direct field and near field effects of the source

In this way the last point can only be taken into account properly if the transmission is described sufficiently by the diffuse field flanking sound reduction index In other cases the transmission of the direct and near field of the source shall by treated separately; see also 4.3.3

4.3.2 Sources

The strength of each source or partial source considered is expressed as the airborne sound power level LW This is measured in accordance with one of several standardized methods based on the basic sound power standards (EN ISO 3740 to EN ISO 3747) For several types of sources also general information is available; see Annex C

If the actual sources are enclosed or partly enclosed the combination can be considered as the source for

which the sound power level follows from the sound power insulation DW of the enclosure and the sound

power level of the enclosed source: Lw = LW,source – DW The sound power insulation can be measured according to EN ISO 11546

The structure can be excited both by the direct sound radiated by the source as by the excitation of the reverberant field by the source Often sources or part of sources are quite close to the room surfaces, making the direct sound and even near field effects important These effects should be taken into account in the sound transmission in the source room; see 4.3.3

4.3.3 Transmission in a source room

The transmission in the source room is given by Ds,i, defined as the logarithm of the ratio between the

effective sound power incident on the element considered i and the total source sound power:

dBlg

Considering the directivity of a source and a diffuse sound field in the source room, it follows directly from the

average distance to the element ri and the absorption in that room As:

dBe

π4

'lg

s

S A 2 i i

s,

t s

S A r

Q D

Q' is the effective directivity factor of the source, including effects of acoustic near fields;

ri is the average distance from source area to element i, in metres;

As is the equivalent absorption area in the source room, in square metres;

St is the total area of the boundaries of the source room

NOTE The term e-A/S is a more general formulation of the more common term (1 -α ) with α the average absorption

coefficient of the room

Only if the distance from the source to the element is large and the room has essentially a diffuse sound field,

this can be approximated as:

dBlg

10

s

i i

S

A s and α can be estimated from material data, using EN 12354-6 In more complex situations - room shape,

large amount of objects - more detailed sound field models should be used; see also Annex D of

EN 12354-6:2003, giving an estimate of A s = 0,16 V / Testimate or an estimate of As for each sub-space in the

source room

4.3.4 Transmission through a building

The transmission through a building is given by the flanking sound reduction index Rij,ref in accordance with

EN 12354-1 In EN 12354-1 it is assumed that direct transmission through a separating element is normally

involved, so the area of the separating element is used as reference area In this case that is often not the

situation, hence a reference area of Sref = 10 m2 is always assumed

The flanking sound reduction index Rij,ref can be estimated using EN 12354-1 on the basis of data on the

elements and junctions involved in the transmission path Additional information for the application in this type

of prediction is given in Annex F

In the case of source positions close to a building element the sound reduction index of that element as

applied in EN 12354-1 may not be relevant; the effect of direct sound fields or near fields has to be taken into

account by an appropriate combination of adjusting the sound reduction index of the element and applying the

effective directivity factor in the sound transmission term Ds,i An alternative is to treat the transmission of the

direct and near field of the source as a separate transmission path

4.4 Structure-borne transmission through building construction

4.4.1 General

The sound power injected into the building structure by the source depends on the characteristics of the

source, the mounting and the supporting building element As a general concept this installed structure-borne

sound power LWs,inst follows from the source strength, given by the characteristic structure-borne sound

power level LWs,c and the coupling term DC for the supporting element i The characteristic structure-borne

sound power is almost the maximum power a source could inject, the coupling term thus being always

positive

The transmission from source room to receiving room normally involves the transmission via various paths

between the supporting building element (i) in the source room and the elements (j) of the receiving room

This transmission can be described by the flanking sound reduction index for that transmission path Rij taking

into account the different excitation mechanisms for airborne and structure-borne sound through the

adjustment term Dsa

The resulting normalized sound pressure level in a room, Ln,s, for one sound source follows from:

dB10

lg

10

n

1 j

10 / s

Ln,s,ij is the normalized sound pressure level in the receiving room due to a structure-borne sound

source mounted to supporting building element i in the source room caused by sound

transmission from element i to a radiating element j in the receiving room, in decibels;

n is the number of elements j in the receiving room participating in the sound transmission

The normalized sound pressure level in the receiving room for each transmission path i,j, Ln,s,ij, follows from

the installed structure-borne sound power level of the source (LWs,inst), the adjustment term Dsa for the

supporting building element and the transmission through the building to the receiving room via the path

considered ij (Rij,ref); see Figure 3

dB4/lg10lg

ref

i ij,ref

sa,i Ws,inst,i

s,ij

S

S R

D L

Rij,ref is the flanking sound reduction index for transmission from element i in the source room to

element j in the receiving room, with reference to the area Sref =10 m2, in decibels;

Si is the area of the supporting building element i in the source room, in square metres;

Aref is the reference equivalent absorption area, in square metres, Aref = 10 m2

NOTE 1 The definition assumes that the reference values for pressure and power are such that ρocoWref / pref2 =1

This is the case with ISO reference values and ρoco = 400 Ns/m 3

The installed structure-borne sound power level follows from the source characteristics and the coupling term

by:

dB

C,i c Ws,

where

LWs,c is the characteristic structure-borne sound power level of the source, in decibels;

DC,i is the coupling term for the source on supporting building element i, in decibels;

NOTE 2 In relatively simple cases this installed power can also be derived more directly from measured quantities In

case the source is essentially a force source with force level LF it follows as LF + 10 lg Re{Yi} and in cases where a source

is essentially a velocity source with velocity level Lv it follows as Lv + 10 lg Re{Zi} – 60 In other simplified cases other

transfer relations could be used; see Annex D

4.4.2 Sources

The strength of each source or partial source under consideration is generally expressed as the characteristic

structure-borne sound power level LWs,c This should be measured in accordance with standardized methods,

but such standardized measurement methods are rare at present However, in order to apply a general form

to the calculation models this general quantity has been chosen to describe the source, allowing

measurement methods to be developed and refined in the future In Annex D additional information is given

on this quantity, such as:

 indications of possible measurement approaches;

 possibilities to deduce this quantity from other related quantities, such as the free velocity at the contact

point, the equivalent force or the appliance sound pressure level;

 global estimations on the basis of results of earlier research

4.4.3 Transmission through the mounting

The power injected in the supporting building element depends on the characteristic structure-borne sound

power and on the characteristics of the source, the type of mounting and the supporting building element This

is characterized by the coupling term DC for element i:

dBlg

10

inj,i

c s,

Winj,i is the structure-borne sound power injected by the source into the supporting building element i,

in Watts

If the source is essentially a single point excitation perpendicular to the supporting building element with

source mobility Ys, this becomes:

dB}Re{

lg

10

i s

2 i s i

Y Y

lg

10

i

s i

lg

The effect of elastic supports (resilient elements, vibration isolators) is included in the coupling term

For a single point excitation perpendicular to the supporting building element through an elastic support with

transfer mobility Yk,m this becomes:

dB}Re{

lg

10

i s

2 m k, i s i

Y Y Y

For several common situations information for the estimation of the coupling term is given in Annex D

4.4.4 Transmission through the building

The transmission through the building is given by the flanking sound reduction index Rij in accordance with

EN 12354-1 and the adjustment term Dsa The estimation of the flanking sound reduction index is already

referred to in 4.3.4 The adjustment term transfers the injected structure-borne sound power to the incident

airborne sound power that excites the same energy level in the supporting building element i, considering only

free vibrations, and follows from:

dB/

/lg10

a i, inc,i

s inj,i

E W

where

Winj,i is the structure-borne sound power injected by the source into the supporting building element i,

in Watts;

Ei.s is the energy of element i due to the structure-borne excitation, in Joules;

Winc,i is the airborne sound power incident on element i, in Watts;

Ei.a is the energy of element i due to the airborne excitation, in Joules

The forced vibrations by airborne sound shall thus be negligible or the results shall be corrected for their contribution In the case of only perpendicular excitation of bending waves for a supporting building element characterised by its airborne transmission coefficient for free vibrations τi and its radiation factor σi this leads to:

dB2,2π2lg

10

i i s, o o

i i i

τ

T c

m

where

mi is the surface mass of element i, in kilograms per square metre;

τi is the transmission coefficient of element i for airborne sound considering free vibrations only

(Ri = - 10 lg τi);

σi is the radiation factor for free bending waves;

Ts,i is the structural reverberation time of element i, in seconds

For several common situations information for the estimation of the adjustment term is given in Annex F

Other sources of sound may be located inside air ducts and air terminals, where sound is caused by air turbulence and air flow at sharp edges This flow generated sound typically increases if the velocity of air transported is increased Sound radiated from vibrating duct walls may have to be taken intro account as well Sound may also be injected into a duct through the wall, an opening, inlet or outlet, if the duct is exposed to high sound pressure levels as may be present in a shaft or equipment room

Typical elements in the system that are to be considered as source and/or transmission elements are:

 high pressure equipment (regenerated sound, radiated sound and insertion loss);

 regulators and valves (regenerated sound and radiated sound);

 nozzles and (supply and return) outlets (reflection-loss)

The sound transmission from the ventilation system to the building is mainly airborne through the ducts (4.2), sometimes structure-borne sound from the fan and motors (4.4) and some times airborne through the building (4.3) The transmission through the duct is also relevant for indirect sound transmission between rooms,

characterised with Dns and applied in accordance with EN 12354-1

Important input data for the transmission model in accordance with EN 12354-1 and EN 12354-2 are the sound reduction indices of the building elements

Various handbooks are already in use to calculate the sound pressure levels due to ventilation systems in rooms Though not necessarily complete in accordance with each other and this standard, we refer to VDI 2081 [1], ASHREA 2003 [2] and ARI 1998 [3] for further details

In Annex H some guidance is given to the preliminary design of an equipment room for ventilation systems as

an example

5.1.2 Guidelines for the application

5.1.2.1 Sources of airborne sound

For the time being it is assumed that the airborne sound of a fan, directly radiated into the enclosed space in

which it is placed, can be characterised by a sound power level, LW,unit This can be used as starting point for the predictions in the same way as for other airborne sound sources (4.2)

To determine the sound pressure level in an equipment room, separately for each sound source, the correction for room absorption and distance to the building elements may be applied in cases where at the distance to room surfaces is large compared to the typical size of the source being considered, i.e the air handling unit, pumps, cooler etc; see 4.3 If surfaces are close to the source the sound pressure level in the

equipment room may be approximated as being numerically equal to the sound power level LW,unit, as given

by the manufacturer, without applying a correction for the room absorption

In cases where large rectangular ducts connect the air handling unit with the primary silencer, it is also necessary to consider also the sound radiated by the duct As a safe estimation, the sound power level of the sound radiated by the duct can be taken as being equal to the airborne sound power from the unit into the

duct, LW,in and/or LW,out, since the sound insulation of rectangular duct panels with low surface mass is negligible Narrow air gaps between the unit and the supporting element (floor) should be avoided, since the sound pressure level may be considerably higher in such air gaps then in the diffuse sound field Mineral wool

in the air gap may reduce sound pressure exposure of the slab only slightly

5.1.2.2 Sources of airborne duct sound

The airborne sound of the fan, directly radiated into the ducts, is characterised by a sound power level, LW,inand LW,out, with respect to the actual operating conditions All other elements in the system can be a sound source too, also characterised by the resulting sound power level upstream and/or downstream The sound power level of other elements (flow regulators, dampers, outlets) depends on airflow (and pressure drop) Manufacturers of these elements can provide these values

5.1.2.3 Sources of radiated sound

The airborne sound power levels of the fan and the other elements in the system can be so high, that the duct (and/or the elements) can radiate a substantial part of this energy into the spaces in the building The sound

pressure level due to this breakout of sound can be assessed taking into account the transmission losses and the dimensions of the radiating surface of the duct Sound radiating values for elements are provided by the manufacturer of the elements (4.2)

5.1.2.4 Sources of structure-borne sound

It is assumed that the main source of any structure-borne sound in ventilation systems will be the fan In some cases the motor, power transmission and any cooling compressor may also cause structure-borne sound The strength of this source is given by the characteristic structure-borne sound power level, which can be deduced from measured data of either an equivalent force level or an equivalent velocity level, for the contact points (stands or footing of the unit) with the building structure These levels should be documented for the equipment with respect to the actual operating conditions

Air handling units constructed with lightweight steel frames or stands can be considered to have a high source mobility and thus behave as force source In Annex D an outline is given of a simplified method to deduce this quantity from the measured force level based on velocity level measurements on a reception plate

For larger cooling compressors or other heavy mechanical devices mounted firmly to the structure or mounted

on vibration isolators, it may be appropriate to consider the source as velocity sources (low source mobility) and use velocity level measurements to estimate the characteristic structure-borne sound power level

NOTE 1 In these cases the injected power in-situ could also be derived directly from the measured force level or velocity level by applying the mobility of the supporting element as indicated in note 2 of Equation (18)

NOTE 2 Internal vibration isolators sometimes work less satisfactorily than expected It is preferable to mount air handling unit on stable stands, which may be replaced by external vibration isolators (resilient mounts) if proved necessary when the unit is commissioned The vibration level of the unit may increase however, which must be taken into account The manufacturer may give advice on feasible measures in this case

5.1.2.5 Sources of transmitted sound (crosstalk)

Sound may be transmitted from one room to other (adjacent or distant) rooms There may be structure-borne sound, but mostly the airborne sound from a source room travels to a receiving room by duct Considering the

“bridging” duct layout, the entry and system losses can be assessed and the sound level in the receiving room calculated This should be compared with the sound insulation between those rooms (See EN 12354-1) Sound may enter and leave the duct through the duct walls or by means of outlets

5.2 Application to heating installations

5.2.1 General

The main types of heating installations are:

 hot water systems with radiators or convectors;

 hot air systems;

 under floor systems (hot water pipes in the floor);

A boiler is a sound source of the combustion process and/or the fan needed for the air supply The sound transmission from the boiler room is partly airborne through the building (4.3) and partly structure-borne (4.4) All other system parts, such as water pipes, radiators and the expansion system cause mainly water – and/or structure-borne sound (4.4) Additional airborne sound sources can be the exhaust openings or air inlet openings; the sound from these sources can enter rooms in the building – or in other buildings – via the outside and could thus be handled in accordance with EN 12354-4

Important input data for the transmission model, in accordance with EN 12354-1 and -2, are the sound reduction indices of the building elements and vibration reduction indices at junctions of building elements

5.2.2 Guidelines

Indications of the airborne sound from burner/boiler combinations are available from past research; see Annex B Less information is available on the structure-borne sound production and it is known that this is not negligible for higher installed heating powers

The expansion system consists of a pipe connecting the boiler to a cistern installed at the highest point of the system For safety reasons, the dimensions of the pipe are greater than for the other pipes of the system These pipes are often mounted rigidly to the floor of the upper storey of a building and the main radiation usually comes from the floor In apartment buildings sound from boilers is also fairly common The dimensions

of these pipes are such that structure-borne sound will be dominant

Circulation pumps have been a notorious sound source, but now very quiet pumps are available borne sound power levels should be available to compare products and to use as input data Sound can be transmitted as water- and/or structure-borne sound to radiators, from where airborne sound is radiated In buildings of medium height, experience indicates that the main part of the sound is water-borne In high-rise buildings (10 storeys or more) more than one circulation pump may be used

Structure-Heat exchangers are not known to produce a large amount of sound However, systems are controlled by valves of which certain, older, types are known to produce a lot of sound (water- and structure-borne transmission to radiators and building elements)

One of the most important sound sources is the valve connected to the radiator The sound generated in the valve is, of course, transmitted to the radiator, from which the main sound radiation occurs So far it has not been possible to distinguish between water- and structure-borne sound and neither have useful test methods been developed and applied, see [5]

The hot water radiator can be a sound source in itself, especially when the pipe system contains un-dissolved air

5.3 Application to lift installations

5.3.1 General

Lift installations, particularly those for passengers, are usually rope suspended or hydraulic, consisting of lift machinery, controller, lift car, counterweight/balancing weight, suspension rope, guide rails and lift doors Lift machine can either be placed in an equipment room or in the well of the lift shaft

Lift machinery with auxiliary equipment and the lift doors are the main sources for airborne sound (4.3) as well

as structure-borne sound (4.4) The guide rails can be a source of structure-borne sound too (4.4)

Elastic supports (vibration isolators) for the lift machine are usually required for adequate reduction of structure-borne sound (4.4) It is therefore beneficial to use heavy structures as supporting building element

In critical transmission situations – nearby rooms, no structural joints between equipment room, well and building – it can be beneficial to improve the effect of a resilient mounting by applying a heavy (concrete) frame above the mounts For the sizing of the elastic supports it should be realized that the lift car and counterweight/balancing weight are part of the total load, but not of the dynamic working load

Guide rails should be mounted on heavy structures and fastened only at high impedance positions on the building structure In critical transmission situations also here elastic supports should be applied The guide rails should be adjusted in such a way that smooth movement of the lift car is assured

Both automatic and hand-operated lift doors can be a source of structure-borne sound In some cases the structure-borne sound caused by door operating in the lift anteroom can be a source of airborne sound in adjacent rooms

5.4 Application to water supply installations

5.4.1 General

Sound of water supply systems includes all sound generated by taps, valves, pumps etc in the fresh water circuit, the sound generated by the flow in the pipe system itself and the sound excited by filling any baths, sinks or basins with fresh water This includes sound generated by splashing water e.g by shower jets etc The sound generated by draining any tanks or sinks is not included and will be considered separately with reference to waste water systems Waste water systems and their sound begin when the water leaves the basins

Typical sources of water supply installations and the relevant type of sound transmission in the defined field of application are listed in Table 1

The general way of transmission for sources in water supply installations is illustrated by Figure 4

Figure – General transmission situation of sources in water supply systems 4

ˆ

‰

Table 1 — Compilation of sources and relevant type of transmission in water supply systems

Fluid borne sound

Direct mounting

Mounting elements Pipes

Valves and taps of any kind:

• Corner stop valves

• Back flow prevention

Figure 5 — Transmission situation for a basin mounted tap

The specific situation for a wall-mounted tap is given in Figure 6

Figure 6 — Transmission situation for a wall mounted tap

Another typical example is given by Figure 7 for a whirlpool path

a) Three-plane corner situation b) Representation

sound power Lw

For calculations according to the general principle given in Figure 4 and the characteristic situations given in Figures 5, 6 and 7 the relevant contributions of airborne, structure-borne and water-borne sound to the

resulting normalized sound pressure level in a room Ln have to be treated separately According to 4.1,

Equation (2), Ln can be calculated as the sum of the individual contributions Dependent from the source and the transmitting situation the following cases may be relevant:

 air borne sound radiation of the source;

 structure borne sound directly transmitted to the building structure or to coupling elements;

 structure and water-borne sound transmitted along a pipe system

Table 1 gives a summary of the generated sound and the transmission situation that normally will be important

Some indications will be given for special installations:

a) for taps and valves the following cases for transmission are relevant:

1) Taps and valves normally generate both water-borne and structure-borne sound travelling along the pipe system and transmitted from the pipes to the building elements as structure-borne sound by mounting elements (clamps etc.) (paths 1 and 2 in Figure 4) In the case of inline valves this will be the relevant transmission path At the moment no standardised method is available to describe both emitted structure-borne and water-borne sound power and no adequate calculation model exists to estimate the effective structure borne sound power or forces at the connection points of a pipe system Some information on how to derive the water and structure-borne sound power of valves and taps is given in [7] In the special case of inline fittings the measurement procedure of EN 1151-2 could be adopted for deriving the structure- and water-borne sound power being transmitted in a pipe system

An approximation is, not to consider the contributions of structure-borne and water-borne sound separately but only to take the sum of both as being responsible for the transmission of structure-borne sound power via mounting elements to building elements This will be valid for mounting points

at a specific distance from the source Experimental results show, that a minimum of about three bends beyond the source will meet this criterion For the time being complete representative systems

of taps, pipes and their mounting elements can be characterised by measurements according to the methods for waste water installations (EN 14366) Regarding the use of data being gained by this standard, see 5.5 Restrictions in the application of this method are given by the requirement that the arrangement tested has to be considered as a force source This normally will be the case in

common heavy homogeneous constructions with m’ > 150 kg/m2 This will not necessarily be the case for lightweight constructions and applicability should be proved for the actual situation

As an approximation the part of sound transmitted by the pipe system (paths 1 and 2 in Figure 4) can be estimated by Equation (D.6a) This equation is based on the measuring methods of EN ISO 3822 and can be considered as a rough estimation of sound generation of a water tap in the case where:

 the tap does not have any direct transmission of structure-borne sound to the building That means the tap is an inline tap or the tap is mounted far away from the emission room so that the direct part of structure borne sound (path 3 in Figure 4) does not play a dominant role for the emission in the receiving room

 The pipe system is considered to be a heavy metallic pipe system

 The clamps tie the pipe rigidly

 The distance between tap and first coupling point to the receiving room is far enough

 The excited wall is a heavy homogeneous wall

2) Taps mounted directly to building elements or basins also will transmit structure-borne sound directly

to the connected structure (path 3 in Figure 4), see also Figures 5 and 6 In many cases this part of structure-borne sound is the dominant part compared with the parts transmitted via the pipe system (paths 1 and 2 in Figure 4) This part has to be treated separately The tap can be considered as a force source as a good approximation in combination with solid walls (m' > 150 kg/m2) For lightweight constructions this assumption has to be proved

3) For taps mounted on a basin (bath tub or wash basin) without direct contact to the building structure the specific situation is given in Figure 4 As a simplification the combination of tap and basin can be treated as one unit described by a common equivalent force Measuring methods according to CEN/TC126WG7 [see prEN 15657-1] can be applied For the time being any combination of taps and basins cannot be defined only by combining mathematically the characteristic quantities of each component A model has to be established (see [8])

For a specific situation it has to be ascertained which of the above-mentioned cases or which combination of them will be relevant The individual contributions have to be treated separately before adding up their contributions Examples of which parts have to be taken into account are given by Figures 5 and 6

NOTE Sound generation characteristics of taps and valves will depend strongly on actual operational conditions (pressure, flow rate, outlet device, throttling of the appliance); input data relevant to the actual situation and operation conditions should be used

b) Pumps in water supply installations can be treated as structure-borne and water-borne sound sources In the case of inline pumps (without connection to building elements) structure-borne and water-borne sound according to paths 1 and 2 in Figure 4 have to be taken into account For these contributions transmitted by the pipe system the measuring methods of EN 1151-2 which have been developed for inline pumps in heating systems can be adopted for pumps in water supply systems

If the pump is connected to a building element additionally structure-borne sound transmitted directly from the pump to the element (path 3 in Figure 4) has to be taken into consideration Experimentally this part can be described by the measuring methods of CEN/TC126/WG7

c) Compact sources such as cisterns, water heaters, boilers etc.:

in the case of structure borne sound a description by an equivalent force or the sound power according to the methods of CEN/TC126/WG7, see prEN 15657-1, is appropriate Air borne sound in special cases

also could play a certain role Then Lw according to the procedures defined in CEN/TC126/WG7, see prEN 15657-1, for estimation of the radiated air borne sound will be relevant

d) In some cases extended sources (bath tubs, whirlpool baths, etc.) are connected to more than one plane (e.g corner position of tubs with connection to the floor and two walls) An example is given in Figure 7

In this case the sources should be treated as three-dimensional sources and the contribution of every direction should be calculated separately (see [9]) Input data for such sources can be obtained according

to the measurement procedures of CEN/TC126/WG7

For airborne sound transmission (4.3) the airborne sound power LWa of the source, as measured in the laboratory (see Annex C), is used in Equation (15) Only the transmission of the diffuse field in the source room can be estimated using the approximation of Equation (16b) The laboratory characterization gives

no information on the direct sound field and near field effect of the equipment and therefore there is no way to estimate the transmission to an element (wall or floor) close to the equipment However, it should

be mentioned that the structure-borne sound power components measured on the three-plate rig includes these airborne sound effects

For the structure-borne sound transmission (4.4) the sum LWs,c+ DC,i of the first two terms in Equation (18a) represents the structural power level injected to building element i in the emission room This power level, called installed power level component i, can be estimated from the corresponding

reference reception plate power level component LWs,n,i as measured in laboratory; see D.1.6

e) In many cases the water jet (e.g from a shower or a tap outlet) splashing on the surface of a basin or tub

or on the water surface can cause the predominant part in structure-borne and airborne sound If relevant this contribution has to be considered separately (see Figures 5, 6 and 7)

5.5 Application to waste water installations

5.5.1 General

A waste water installation is composed of any combination of straight pipes with tees, bends, joints and inlets, mounted on the building structures through fixing devices (often clips) Vibration is generated by the flow and fall of water in the piping system and either directly radiates sound (airborne sound) or is transmitted to the receiving structures (walls or floors to which the installation is fixed), which radiate sound (structure-borne sound); particular fixing devices can be used to reduce the structure-borne sound See also [9] and [10]

The structure-borne sound and airborne sound from a waste water installation is measured in accordance with

EN 14366 in a special set-up; see Annex D Two quantities are obtained from the standard: the normalized

airborne sound pressure level, Lan, and the characteristic structure-borne sound pressure level, Lsc, both for a specified section of the waste water installation and a specific mounting method The waste water pipe is usually connected to a supporting wall through two fixation points quite far apart and considered as being uncorrelated; the source type is therefore reduced to a single contact point source These input data can be used for the prediction of airborne and structure-borne sound transmission; see 5.5.2

In EN 14366, the actual sources of the waste water, e.g sinks, toilets, bathtubs, gutter or any active units (pumps) are excluded

5.5.2 Guidelines for the application

The airborne sound power level, LW, and the characteristic structure borne power level LWs,c can be calculated from the two quantities obtained from EN 14366:2004 through the relations given in Annex C (C.1.1) and Annex D (D.1.7) of that standard

For the airborne sound transmission, see 4.3 Only the transmission of the diffuse sound field in the source room can be estimated using the approximation of Equation (16b) See also Annex C

For the structure-borne sound transmission, see 4.4 The supporting building element is usually a homogeneous plate for which the mobility can be estimated from the infinite plate mobility, see F.4 Assuming

a force source the source mobility is taken as the (high) reference value Ys,ref= 10-3 m/Ns, thus the coupling

term can be taken as in Annex D with Yi in accordance with Annex F

If the structural sensitivity level from the mounting wall to a room LSS,situ in a given field situation is known (measured for example as indicated in EN 14366), then also the resulting normalized sound level as in Equation (18) can be calculated by Equation (21):

5.6.2 Guidelines

The airborne sound production by dishwashers or washing machines can be determined in accordance with

international standards (relevant parts of IEC 704) and is expressed as the sound power level LW

For the structure-borne sound production no measurement standards exist as yet Proposals have been described using a reception plate method to determine the equivalent force level Research has shown that the source impedance at low frequencies – the important frequency range – is mass-like, characterised by a mass of typically 5 kg to 10 kg [11] As indicated in annex F this type of information is sufficient to estimate the

characteristic structure-borne sound power level LWs,c and the relevant relations for the coupling terms

Normally there will not be any transmission element involved in the transmission of sound from household equipment, but occasionally (partial) insulating enclosures or elastic supports are applied

The relevant airborne sound levels for household equipment are mainly the levels in the installations room itself The normalized sound pressure level can be estimated as 4 dB lower than the sound power level of the source at sufficient distance from that source (reverberant field)

The structure-borne sound levels follow the model as described in 4.4.1 with the appropriate coupling term as discussed above and Annex F

6 Accuracy

The accuracy of predicted sound levels due to service equipment in buildings depends on many aspects such

as the available input data for sources and structures, the complexity of the modelled situation, the predominant sound transmission mechanism and the relevant frequency range The main distinction should

be made between the accuracy of source input data and the accuracy of the transmission predictions Values for these accuracies will differ between types of installations but quantitive information is scarce as yet

As a global indication the expanded uncertainty for the single number ratings (A- or C-weighted levels) with a coverage factor of 2 could be estimated as up to 5 dB for the source input data and up tot 5 dB for the transmission predictions; assuming these two aspects to be independent the overall expanded uncertainty would thus be up to 7 dB Based on some global experience with comparable prediction schemes a more detailed overview of the estimated uncertainties is given in Table 2 More research and comparison will be needed to be able to specify these uncertainties more accurately and in more detail

Table 2 – Global estimate of the expanded uncertainty for various types of service equipment in

buildings

Source type source input data transmission remarks

Annex A

(normative)

List of symbols

Table A.1 — List of symbols

d Distance between the sound radiating element in the room and the receiver position m

Dn,s Normalized sound level difference for indirect transmission through a system s dB

Dt,oi Sound power transmission loss for a duct opening or device for transmission from

DC,i Coupling term for the source on supporting building element i dB

Dsa,i Adjustment term from structure-borne to airborne excitation for supporting building

DΩ Solid angle directivity index for radiating element or source in a room dB

Ei.s Energy of element i due to the structure-borne sound excitation J

km Frequency-averaged dynamic transfer stiffness for elastic support m N/m

l Actual length of element, as measured along the centre line of the duct m

Ln Total normalized sound pressure level in a room due to all sources dB re 20 µ Pa

LnT Total standardized sound pressure level in a room due to all sources dB re 20 µ Pa

Table A.1 (continued)

Ln,d,i Normalized sound pressure level due to sound transmission through a pipe or duct

Ln,a,j Normalized sound pressure level due to airborne sound transmission through the

Ln,s,k Normalized sound pressure level due to structure-borne sound transmission

Lo The sound pressure level in the source room and/or outside a duct dB re 20 µ Pa

Ln,a,ij Normalized sound pressure level in the receiving room due to an airborne sound

source in the source room, as caused by sound transmission from an excited

element i in the source room and a radiating element j in the receiving room

dB re 20 µ Pa

Ln,s,ij Normalized sound pressure level in the receiving room due to a structure-borne

sound source mounted to supporting building element i in the source room, as

caused by sound transmission from an excited element i in the source room and a

radiating element j in the receiving room

dB re 20 µ Pa

LW,in Sound power level of an air moving device, into the inlet duct dB re 1 pW

LW,out Sound power level of an air moving device, into the outlet duct dB re 1 pW

LW,unit Sound power level of an air moving device, radiated from the casing dB re 1 pW

LWs,c Characteristic structure-borne sound power level of a structure-borne sound source dB re 1 pW

LWs,inst Injected structure-borne sound power level of a source when installed on a

m Number of elements i in the source room participating in the sound transmission,

number of sound sources related to duct transmission, number

-

n Number of elements j in the receiving room participating in the sound transmission,

number of airborne sound sources

-

Q’ Effective directivity factor of a source, including effects of acoustic near fields -

Rij,ref Flanking sound reduction index for transmission from element I in the source room

to element j in the receiving room, with reference to the area Sref= 10 m 2 dB

Roi Sound reduction index of the duct for transmission from outside to inside dB

Rio Sound reduction index of the duct for transmission from inside to outside dB

S1 Area of the first element (i = 1) of the transmission system in the source room, i.e

2

Table A.1 (continued)

Si Area of the excited element i or supporting element i in the source room m 2

Scd,d Area of the cross section of the duct at the downstream end of the exposed part of

Winj,i Structure-borne sound power injected by the source into supporting building

Re{Yi} Real part of the mobility of the element i at the excitation point m/Ns

∆L'W Sound power level reduction per unit or unit length of an element dB

τi Transmission coefficient of element i for airborne sound; Ri = -10lg τi -