BRITISH STANDARD Acoustics — Determination of sound power levels of noise from air-terminal devices, air-terminal units, dampers and valves by measurement in a reverberation room The European Standard EN ISO 5135:1998 has the status of a British Standard ICS 17.140.20; 91.140.30 BS EN ISO 5135:1999 BS EN ISO 5135:1999 National foreword This British Standard is the English language version of EN ISO 5135:1998 It is identical with ISO 5135:1997 It supersedes BS 4773-2:1989 which is withdrawn The UK participation in its preparation was entrusted by Technical Committee EH/1, Acoustics, to Subcommittee EH/1/4, Machinery noise, which has the responsibility to: — aid enquirers to understand the text; — present to the responsible international/European committee any enquiries on the interpretation, or proposals for change, and keep the UK interests informed; — monitor related international and European developments and promulgate them in the UK A list of organizations represented on this subcommittee can be obtained on request to its secretary Cross-references Attention is drawn to the fact that CEN and CENELEC standards normally include an annex which lists normative references to international publications with their corresponding European publications The British Standards which implement these international or European publications may be found in the BSI Standards Catalogue under the section entitled “International Standards Correspondence Index”, or by using the “Find” facility of the BSI Standards Electronic Catalogue A British Standard does not purport to include all the necessary provisions of a contract Users of British Standards are responsible for their correct application Compliance with a British Standard does not of itself confer immunity from legal obligations Summary of pages This document comprises a front cover, an inside front cover, pages i and ii, the EN ISO title page, page 2, the ISO title page, page ii, pages to 12, an inside back cover and a back cover This standard has been updated (see copyright date) and may have had amendments incorporated This will be indicated in the amendment table on the inside front cover This British Standard, having been prepared under the direction of the Health and Environment Sector Committee, was published under the authority of the Standards Committee and comes into effect on 15 March 1999 © BSI 05-1999 ISBN 580 30759 X Amendments issued since publication Amd No Date Comments BS EN ISO 5135:1999 Contents National foreword Foreword Foreword Text of ISO 5135 © BSI 05-1999 Page Inside front cover ii i ii blank EUROPEAN STANDARD EN ISO 5135 NORME EUROPÉENNE December 1998 EUROPÄISCHE NORM Supersedes EN 25135:1991 ICS 17.140.20 Descriptors: See ISO document English version Acoustics — Determination of sound power levels of noise from air-terminal devices, air-terminal units, dampers and valves by measurement in a reverberation room (ISO 5135:1997) Acoustique — Détermination des niveaux de puissance acoustique du bruit émis par les bouches d’air, les unités terminales, les registres et clapets au moyen de mesurages en salle réverbérante (ISO 5135:1997) Akustik — Bestimmung des Schalleistungspegels von Geräuschen von Luftdurchlässen, Volumenstromreglern, Drossel- und Absperrelementen durch Messungen im Hallraum (ISO 5135:1997) This European Standard was approved by CEN on December 1998 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 Central Secretariat 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 Central Secretariat has the same status as the official versions CEN members are the national standards bodies of Austria, Belgium, Czech Republic, Denmark, Finland, France, Germany, Greece, Iceland, Ireland, Italy, Luxembourg, Netherlands, Norway, Portugal, Spain, Sweden, Switzerland and United Kingdom CEN European Committee for Standardization Comité Européen de Normalisation Europäisches Komitee für Normung Central Secretariat: rue de Stassart 36, B-1050 Brussels © 1998 CEN All rights of exploitation in any form and by any means reserved worldwide for CEN national Members Ref No EN ISO 5135:1998 E EN ISO 5135:1998 Foreword Contents The text of the International Standard from Technical Committee ISO/TC 43 “Acoustics” of the International Organization for Standardization (ISO) has been taken over as an European Standard by Technical Committee CEN/TC 211 “Acoustics”, the secretariat of which is held by DS This European Standard replaces EN 25135:1991 This European Standard shall be given the status of a national standard, either by publication of an identical text or by endorsement, at the latest by June 1999, and conflicting national standards shall be withdrawn at the latest by June 1999 According to the CEN/CENELEC Internal Regulations, the national standards organizations of the following countries are bound to implement this European Standard: Austria, Belgium, Czech Republic, Denmark, Finland, France, Germany, Greece, Iceland, Ireland, Italy, Luxembourg, Netherlands, Norway, Portugal, Spain, Sweden, Switzerland and the United Kingdom Page Foreword Introduction 1 Scope Normative references Definitions Acoustic test facilities and procedures Installation and operation of equipment to be tested Auxiliary facilities Measurements and calculations Test report Annex A (informative) Bibliography Inside back cover Annex ZA (normative) Normative references to international publications with their relevant European publications Inside back cover Figure — Location of equipment in test room Figure — Mounting detail for air-terminal device installed on or against a surface Figure — Mounting detail for equipment installed at intersection of two surfaces Figure — Mounting detail for air-terminal device installed away from surface Figure — Mounting detail for air-terminal units installed outside room boundary Figure — Mounting detail for air-terminal unit to determine casing radiated sound 10 Figure a) — Examples of LW and LWA plotted against lg(qV) for a test with constant total pressure loss coefficient 11 Figure b) — Examples of LW and LWA plotted against lg(%pt) for a test with constant flow rate 12 Table — Values of for the configurations illustrated in Figure Endorsement notice The text of the International Standard ISO 5135:1997 has been approved by CEN as a European Standard without any modification NOTE Normative references to International Standards are listed in Annex ZA (normative) © BSI 05-1999 EN ISO 5135:1998 Foreword ISO (the International Organization for Standardization) is a worldwide federation of national standards bodies (ISO member bodies) The work of preparing International Standards is normally carried out through ISO technical committees Each member body interested in a subject for which a technical committee has been established has the right to be represented on that committee International organizations, governmental and non-governmental, in liaison with ISO, also take part in the work ISO collaborates closely with the International Electrotechnical Commission (IEC) on all matters of electrotechnical standardization Draft International Standards adopted by the technical committees are circulated to the member bodies for voting Publication as an International Standard requires approval by at least 75 % of the member bodies casting a vote International Standard ISO 5135 was prepared by ISO/TC 43, Acoustics, Subcommittee SC 1, Noise This second edition cancels and replaces the first edition (ISO 5135:1984), of which it constitutes a technical revision Annex A of this International Standard is for information only Descriptors: Acoustics, air terminal devices, pressure equipment, dampers, valves, noise (sound), engine noise, tests, acoustic tests, determination, sound power, acoustic measurements ii © BSI 05-1999 EN ISO 5135:1998 Introduction Definitions This International Standard defines requirements for acoustic testing in reverberation rooms of the type of equipment listed in clause It is based on the use of ISO 3741, which describes the acoustic test facilities, instrumentation and procedures to be used for precision grade determination of sound power levels in octave or one-third-octave bands of a noise source For the purposes of this International Standard, the following definitions apply Scope 3.1 sound pressure level Lp ten times the logarithm to the base 10 of the ratio of the mean-square sound pressure of a sound to the square of the reference sound pressure, in decibels NOTE The reference sound pressure is 20 4Pa This International Standard establishes general rules for the acoustic testing of air-terminal units, dampers and valves used in air diffusion and air distribution systems as defined in ISO 3258 in order to determine sound power levels as defined in ISO 3740 3.2 sound power level Normative references NOTE The following standards contain provisions which, through reference in this text, constitute provisions of this International Standard At the time of publication, the editions indicated were valid All standards are subject to revision, and parties to agreements based on this International Standard are encouraged to investigate the possibility of applying the most recent editions of the standards indicated below Members of IEC and ISO maintain registers of currently valid International Standards ISO 3258:1976, Air distribution and air diffusion — Vocabulary ISO 3740:1980, Acoustics — Determination of sound power levels of noise sources — Guidelines for the use of basic standards and for the preparation of noise test codes ISO 3741:—, Acoustics — Determination of sound power levels of noise sources using sound pressure — Precision methods for reverberation rooms1) ISO 5219:1984, Air distribution and air diffusion — Laboratory aerodynamic testing and rating of air terminal devices ISO 5220:1981, Air distribution and air diffusion — Aerodynamic testing and rating of constant and variable dual or single duct boxes and single duct units 1) To LW ten times the logarithm to the base 10 of the ratio of a given sound power to the reference sound power, in decibels The reference sound power is pW ( = 10– 12 W) 3.3 frequency range of interest the range which includes the octave bands with midband frequencies between 63 Hz and 000 Hz or the one-third-octave bands with midband frequencies between 50 Hz and 10 000 Hz NOTE Many rooms will not be qualified for measurements below the one-third-octave band centred at 100 Hz and the octave band centred at 125 Hz, respectively In these cases the result may still be reported provided that all deviations are clearly indicated in the test report 3.4 reverberant sound field that portion of the sound field in the test room over which the influence of sound received directly from the source is negligible Acoustic test facilities and procedures This International Standard is applicable to equipment operating under steady state conditions and with a volume less than % of the volume of the reverberation room The acoustic test facilities, instrumentation and procedures to be used, including room qualification tests, are described in ISO 3741 This document offers a choice of two methods for reverberation room measurements for determining sound power levels The comparison method uses a reference sound source having a known sound power output The direct method requires knowledge of the reverberation time of the room in which the determination is made be published (Revision of ISO 3741:1988 and ISO 3742:1988) © BSI 05-1999 EN ISO 5135:1998 If there are substantial variations in the reverberant room characteristics due to the presence of the source to be tested, then the test room shall also be qualified according to ISO 3741 with all equipment present in the room Installation and operation of equipment to be tested 5.1 General 5.1.1 When the equipment is mounted closer than m to one or more reflecting planes the sound power level may depend strongly on the position of the equipment relative to these planes Therefore, install the equipment to be tested in a position representative of normal usage Figure illustrates the overall test environment, with the specific details of each type shown in Figure to Figure NOTE Reflecting planes may, for practical reasons, be simulated by panels with an area-related mass greater than kg/m2 Such panels should extend at least 1,2 m in all directions measured from any edge of the device under test These panels should be vibration isolated from the equipment under test 5.1.2 Supply air to the equipment under test or exhaust air from it through a test installation in accordance with ISO 5219 or ISO 5220 5.1.3 Include air-flow control accessories (dampers, deflectors, straighteners, equalizers, etc.) normally used in conjunction with the equipment under test in the test set-up Locate and set them in the same manner as recommended for the application of the equipment 5.2 Test installation of air-terminal units, dampers and valves for measurement of the sound radiated to the reverberation room 5.2.1 Position air-terminal devices normally installed in a boundary surface no closer than m to the intersection of any adjacent surface and away from any position of boundary surface symmetry, as shown in Figure 5.2.2 Mount air-terminal devices normally used at the intersection of two surfaces at the intersection of the two surfaces not closer than m to a third surface as shown in Figure 5.2.3 Install air-terminal devices not normally positioned at any boundary surface within the test room no closer than m to any surface and away from any position of room symmetry Examples are shown in Figure Diffusers installed on ducts without adjacent ceiling are typical examples 5.2.4 The installation details specified in 5.2.1 to 5.2.3 apply equally to air-terminal devices when integral with air-terminal units In this case measure a combined total of radiated sounds 5.3 Test installation of air-terminal units, dampers and valves for the measurement of the sound radiated to the reverberation room by the connecting duct To measure equipment normally located above the ceiling or in another space adjacent to the room they serve, install the equipment outside the test room and connect it to the test room by an unlined duct 1,5 m long of the same cross-sectional shape and area as the equipment connection in the room (see Figure 5) Terminate the duct flush with all surfaces of the test room no closer than m to any adjacent surface and away from any position of room symmetry Examples are shown in Figure 5.4 Test installation of air-terminal units for the determination of casing radiated noise To determine the sound radiated from the casing, install the unit in the reverberation room with suitable connecting duct or ducts in accordance with 6.2.3 and with ISO 5220 Install the unit within the size limits as shown in Figure Carry out the measurements in accordance with the following two methods 5.4.1 In the case of the two-duct method, two ducts connecting the unit to the outside of the reverberation room are required 5.4.2 In the case of the one-duct method, one duct connecting the unit to the outside of the reverberation room is required In order to obtain the casing radiated sound, calculate the difference between the sound power levels, LW, for each octave band or one-third-octave band, derived from this test, and the corresponding sound power levels derived from the test described in 5.3 This method is only valid if the difference is equal to or greater than dB 5.5 Test procedures 5.5.1 Carry out acoustic measurements while the equipment is operating over a range of conditions typical of its normal use 5.5.1.1 For non-adjustable air-terminal devices, carry out sound measurements for a minimum of four air-flow rates over the upper half of the normal range used to determine the air-terminal device pressure requirements given in ISO 5219 5.5.1.2 For adjustable pattern air-terminal devices, carry out sound measurements for a minimum of four air-flow rates over the upper half of the normal range for each of the adjustment positions for which the test data is required 5.5.1.3 For air-terminal units with adjustable flow rate, carry out sound measurements for a minimum of four air-flow rates, each at the minimum, maximum and at least two intermediate flow rates © BSI 05-1999 EN ISO 5135:1998 5.5.2 If the operation of equipment in its normal range generates sound pressure levels below the measurement limit, then higher flow rates may be used and acoustic results recorded at least at the specified number of tests and extrapolated to the normal range The following procedure may be used for extrapolation a) In the case of tests made at a constant total pressure loss coefficient, plot values of sound power levels, LW, for each octave or one-third-octave band and of A-weighted sound power levels, LWA, against lg(qV), where qV is the volume flow rate b) In the case of tests made at a constant flow rate, plot LW for each octave or one-third-octave band and LWA against lg(%pt), where %pt is the total pressure loss Draw best-fit straight lines through the points for each parameter using the least squares method The maximum deviation between the measured points and a straight line shall be ± dB These lines may be extended down to half the minimum and up to twice the maximum values of qV or %Pt Values of LW or LWA corresponding to specific values of qV or %Pt within the above range may be derived from the graphs [see examples in Figure a) and Figure b)] Auxiliary facilities 6.1 General Any noise due to electrical conduits, piping or air ducts connected to the equipment shall be at least dB, and preferably more than 10 dB, below the sound pressure level to be measured 6.2.2 Vent air to or from the test room through a silencer Carry out all sound measurements of the equipment under test, the reference sound source and background noise (see the note in 6.2.1) with the sound attenuator in place in a consistent manner Noise generated by flow through the sound attenuator shall be in accordance with the requirements for background noise (see the note in 6.2.1) 6.2.3 The connecting supply and exhaust ducts for the installation set out in 5.4 (casing radiation) shall radiate noise at least dB, and preferably more than 10 dB, below the sound pressure level to be measured in each frequency band within the frequency range of interest Correct for background sound pressure levels in accordance with ISO 3741 Measurements and calculations The determination of the importance of discrete-frequency or narrow-band components, the qualification of the reverberation room, the measurements of the sound pressure levels and the calculation of the sound power levels for all octave bands within the frequency range of interest and the calculation of A-weighted sound power level, LWA, shall be carried out in accordance with ISO 3741 In the case of the installation described in 5.3, calculate the sound power level in the connecting duct, LWduct, by adding the end reflection loss of the open duct, %Lr, to the sound power level, LW, radiated into the room according to the following formula: LWduct = LW + %Lr where 6.2 Auxiliary facilities for acoustic testing 6.2.1 Provide a quiet air system so that any background noise lies at least dB, and preferably more than 10 dB, below the sound pressure level to be measured in each frequency band within the frequency range of interest Correct for background sound pressure levels with differences of dB to 10 dB in accordance with ISO 3741 NOTE For the purpose of this International Standard, the background sound pressure level during test with air flow through the air-terminal device should be checked by removing the air-terminal device and measuring the sound pressure levels at approximately the same volume rates of air flow used in the test However, it should be borne in mind that, in some cases, the noise from the air terminal may be lower than that of the system without terminal © BSI 05-1999 (1) (2) where c is the speed of sound; f is the band centre frequency; S is the area of the duct opening in the room; is the solid angle of the radiation path from the test opening (see Table 1) EN ISO 5135:1998 Table — Values of Ë for the configurations illustrated in Figure Configuration A 2; B ; C 4; D 2; E 4; NOTE As an alternative to the correction according to equation (2), a transmission element according to ISO 7235 may be used without any corrections Test report The following information shall be included in the test report: a) date of tests; b) description of the equipment under test; c) location and mounting of the equipment under test, including a sketch; d) description and qualification of reverberation room (including dimensions); e) a statement that all reported results have been obtained in full conformity with this International Standard; f) volume flow rate, temperature and gauge pressure of the air flow entering the test unit; g) the bandwidth of frequency analysis; h) operating conditions of the source related to the sound power levels for all frequency bands within the frequency range of interest (see 3.3); i) the corrections, if any, applied in each frequency band for the frequency response of the total instrumentation system, background noise and end reflection, in decibels; j) air temperature, relative humidity and barometric pressure during the measurements; k) at selected operating points of interest for the equipment tested, the fully corrected and computed sound power levels, in decibels, tabulated or plotted to the nearest half decibel for each frequency band considered — it shall be clearly stated whether extrapolated values are reported or if all points fall within the range measured directly; l) the A-weighted sound power level, LWA, for all operating conditions of the source © BSI 05-1999 EN ISO 5135:1998 NOTE Refer to 5.2, 5.3 and 5.4 for mounting details Figure — Location of equipment in test room © BSI 05-1999 EN ISO 5135:1998 Figure — Mounting detail for air-terminal device installed on or against a surface © BSI 05-1999 EN ISO 5135:1998 Figure — Mounting detail for equipment installed at intersection of two surfaces © BSI 05-1999 EN ISO 5135:1998 Figure — Mounting detail for air-terminal device installed away from surface © BSI 05-1999 EN ISO 5135:1998 Figure — Mounting detail for air-terminal units installed outside room boundary © BSI 05-1999 EN ISO 5135:1998 Figure — Mounting detail for air-terminal unit to determine casing radiated sound 10 © BSI 05-1999 EN ISO 5135:1998 Figure a) — Examples of LW and LWA plotted against lg(qV) for a test with constant total pressure loss coefficient © BSI 05-1999 11 EN ISO 5135:1998 Figure b) — Examples of LW and LWA plotted against lg(%pt) for a test with constant flow rate 12 © BSI 05-1999 EN ISO 5135:1998 Annex A (informative) Bibliography [1] ISO 7235:1991, Acoustics — Measurement procedures for ducted silencers — Insertion loss, flow noise and total pressure loss Annex ZA (normative) Normative references to international publications with their relevant European publications This European Standard incorporates by dated or undated reference, provisions from other publications These normative references are cited at the appropriate places in the text and the publications are listed hereafter For dated references, subsequent amendments to or revisions of any of these publications apply to this European Standard only when incorporated in it by amendment or revision For undated references the latest edition of the publication referred to applies Publication Year Title EN Year ISO 3741 1988 Acoustics — Determination of sound power levels of noise sources — Precision methods for broad-band sources in reverberation rooms EN 23741 1991 © BSI 05-1999 BS EN ISO 5135:1999 BSI — British Standards Institution BSI is the independent national body responsible for preparing British Standards It presents the UK view on standards in Europe and at the international level It is incorporated by Royal Charter Revisions British Standards are updated by amendment or revision Users of British Standards should make sure that they possess the latest amendments or editions It is the constant aim of BSI to improve the quality of our products and services We would be grateful if anyone finding an inaccuracy or ambiguity while using this British Standard would inform the 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Road London W4 4AL If permission is granted, the terms may include royalty payments or a licensing agreement Details and advice can be obtained from the Copyright Manager Tel: 020 8996 7070 ... 4Pa This International Standard establishes general rules for the acoustic testing of air- terminal units, dampers and valves used in air diffusion and air distribution systems as defined in ISO. .. air- terminal units In this case measure a combined total of radiated sounds 5.3 Test installation of air- terminal units, dampers and valves for the measurement of the sound radiated to the reverberation. .. than m to any adjacent surface and away from any position of room symmetry Examples are shown in Figure 5.4 Test installation of air- terminal units for the determination of casing radiated noise