GB/T 34877.2-2023 Industrial fans—Determination of fan sound power levels under standardized laboratory conditions—Part 2:Reverberant room method (English Version)
Industrial fans - Determination of fan sound power levels under standardized laboratory conditions - Part 2: Reverberant room method
1 Scope
This document gives a detailed description of reverberant room methods for the determination of fan sound power levels. It is for use under standardized laboratory conditions and recognises that tests in situ are subject to increased uncertainty. These test procedures are not necessarily appropriate to site test conditions. Acoustic system effects are presently the subject of considerable research effort.
ISO 5136, which covers the in-duct method, and ISO 10302 for small fans, should be used in conjunction with this document.
2 Normative references
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.
GB/T 1236-2017 Industrial fan - Performance testing using standardized airways (ISO 5801:2007, IDT)1)
Note: There is no technical difference between the referenced content of GB/T 1236-2017 and the referenced content of ISO 5801:2007.
GB/T 19843-2005 Industrial fan - Performance testing of jet fans (ISO 13350:1999, IDT)
GB/T 25516-2010 Acoustics - Laboratory measurement procedures for ducted silencers and air - Terminal units loss, flow noise and total pressure loss (ISO 7235:2003, IDT)
GB/T 21231.1-2018 Acoustics - Measurement of airborne noise emitted and structure-borne vibration induced by small air-moving devices - Part 1: Airborne noise measurement (ISO 10302-1:2011, IDT)2)
Note: There is no technical difference between the referenced content of GB/T 21231.1-2018 and the referenced content of ISO 10302-1:2011.
GB/T 34877.1-2023 Industrial fans - Determination of fan sound power levels under standardized laboratory conditions - Part 1: General overview (ISO 13347-1:2004, IDT)
ISO 3740 Acoustics - Determination of sound power levels of noise sources - Guidelines for the use of basic standards
Note: GB/T 14367-2006, Acoustics - Determination of sound power levels of noise sources - Guidelines for the use of basic standards (ISO 3740:2000, MOD)
ISO 3741 Acoustics - Determination of sound power levels of noise sources using sound pressure - Precision methods for reverberation rooms
Note: GB/T 6881.1-2002, Acoustics - Determination of sound power levels of noise sources using sound pressure - Precision methods for reverberation rooms (ISO 3741:1999, IDT)
ISO 3743-1 Acoustics - Determination of sound power levels and sound energy levels of noise sources using sound pressure - Engineering methods for small movable sources in reverberant fields – Part 1: Comparison method for a hard-walled test room
Note: GB/T 6881.2-2017, Acoustics - Determination of sound power levels and sound energy levels of noise sources using sound pressure - Engineering methods for small movable sources in reverberant fields - Comparison method for a hard-walled test room (ISO 3741-1:2010, IDT)
ISO 3743-2 Acoustics - Determination of sound power levels of noise sources using sound pressure - Engineering methods for small, movable sources in reverberant fields - Part 2: Methods for special reverberation test rooms
Note: GB/T 6881.3-2002, Acoustics - Determination of sound power levels of noise sources-using sound pressure - Engineering methods for small, movable sources in reverberant field - Part 2: Methods for special reverberation test rooms (ISO 3741-2:1994, IDT)
ISO 5136 Acoustics - Determination of sound power radiated into a duct by fans and other air-moving devices - In-duct method
Note: GB/T 17697-2014, Acoustics - Determination of sound power radiated into a duct by fans and other air-moving devices - In-duct method (ISO 5136:2003, IDT)
ISO 5801 Industrial fans - Performance testing using standardized airways
Note: GB/T 1236-2017, Industrial fan - Performance testing using standardized airways (ISO 5801:2007, IDT)
ISO 7235 Acoustics - Laboratory measurement procedures for ducted silencers and air-terminal units - Insertion loss, flow noise and total pressure loss
Note: GB/T 25516-2010, Acoustics - Laboratory measurement procedures for ducted silencers and air - Terminal units loss, flow noise and total pressure loss (ISO 7235:2003, IDT)
ISO 10302-1 Acoustics - Measurement of airborne noise emitted and structure-borne vibration induced by small air-moving devices - Part 1: Airborne noise measurement3)
Note: GB/T21231.1-2018, Acoustics - Measurement of airborne noise emitted and structure-borne vibration induced by small air-moving devices - Part 1: Airborne noise measurement (ISO 10302-1:2011, IDT)
ISO 13349 Industrial fans - Vocabulary and definitions of categories
Note: GB/T 19075-2003, Industrial fans - Vocabulary and definitions of categories (ISO 13349:1999, IDT)
3 Terms and definitions
No terms and definitions are listed in this document.
4 Limitations on use
This document applies to industrial fans as defined by ISO 5801 and ISO 13349; it is limited to determining the airborne noise radiation of the specified installation and does not measure vibration or the sensitivity of the airborne sound radiation to the effects of vibration.
The size of the fan tested in accordance with this document is limited only by the actual location of the test arrangement; the size of the test fan and the aerodynamic performance will control the size of the chamber. (Smaller fans may be tested in accordance with this document or ISO10302-1, depending on the application).
The test arrangement in this document establishes the necessary laboratory conditions for successful testing; it is difficult to meet these requirements in the field and this document is not intended for field measurements; we caution the intended user that in these cases the acoustic environment may not meet the specified conditions and that additional acoustic system effects are likely to occur if the inlet and outlet conditions of the fan are less than ideal.
5 Field of application
This document deals with the determination of the acoustic performance of industrial fans and, in addition, may be used to determine the acoustic performance of fans combined with an ancillary device such as a roof cowl or damper or, where the fan is fitted with a silencer, the sound power resulting from the fan and silencer combination.
For low power fans (up to 3 kW) that could be run from a domestic power supply (single phase AC at a voltage not exceeding 250 V and a current not exceeding 16 A), reference should be made to the appropriate IEC standard for household and similar fans, IEC 60704-2-7.
For reverberant field tests, the size of equipment under test is limited to less than 2 % of the room volume. A test procedure is specified in Clause 9 of GB/T 19843-2005 for testing jet fans.
The test procedures specified in this document are intended principally for tests conducted using standardized test configurations and under specified environments and conditions, and may not be appropriate to site test conditions.
The fan installation conditions conform to the four categories of installation types specified in ISO 5801:
a) type A: free inlet, free outlet;
b) type B: free inlet, ducted outlet;
c) type C: ducted inlet, free outlet;
d) type D: ducted inlet, ducted outlet.
5.1 Noise source
The noise source is a fan. The noise measured may contain contributions from the fan drive and transmission.
5.2 Character of noise
Steady broad band with discrete frequency tones.
5.3 Uncertainty
Engineering grade as defined in ISO 3740.
5.4 Quantities to be measured
Sound pressure levels in one-third octave frequency bands at discrete microphone positions or on a prescribed path.
Fan aerodynamic performance indicators including rotational speed, fan pressure and flowrate.
6 Instrumentation
Full details of the instrumentation and its requirements are given in ISO 13347-1. This also details the requirements for the reference sound source which shall be used to qualify the test room and shall be the basis of the substitution method. To be used for these purposes, the reference sound source (RSS) shall be of an appropriate type, be calibrated accurately and be properly maintained.
7 Test method
The test method is based on a reference sound source (RSS) substitution for the determination of sound power. The reference documents for this method are ISO 3743-1 and ISO 3743-2.
Application of the test method requires that the fan to be tested be set in position in a test room, which is qualified according to the requirements of Annex A.
Once the test room has been qualified, sound pressure levels are recorded with the RSS operating. The fan is then operated without the RSS in operation at various performance points of interest for the given test speed, and the fan sound pressure levels are recorded. Since the sound power levels of the RSS are known, the substitution method is used to determine the sound power levels of the fan for each operating point.
Standard
GB/T 34877.2-2023 Industrial fans—Determination of fan sound power levels under standardized laboratory conditions—Part 2:Reverberant room method (English Version)
Standard No.
GB/T 34877.2-2023
Status
valid
Language
English
File Format
PDF
Word Count
10500 words
Price(USD)
315.0
Implemented on
2024-7-1
Delivery
via email in 1~3 business day
Detail of GB/T 34877.2-2023
Standard No.
GB/T 34877.2-2023
English Name
Industrial fans—Determination of fan sound power levels under standardized laboratory conditions—Part 2:Reverberant room method
Industrial fans - Determination of fan sound power levels under standardized laboratory conditions - Part 2: Reverberant room method
1 Scope
This document gives a detailed description of reverberant room methods for the determination of fan sound power levels. It is for use under standardized laboratory conditions and recognises that tests in situ are subject to increased uncertainty. These test procedures are not necessarily appropriate to site test conditions. Acoustic system effects are presently the subject of considerable research effort.
ISO 5136, which covers the in-duct method, and ISO 10302 for small fans, should be used in conjunction with this document.
2 Normative references
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.
GB/T 1236-2017 Industrial fan - Performance testing using standardized airways (ISO 5801:2007, IDT)1)
Note: There is no technical difference between the referenced content of GB/T 1236-2017 and the referenced content of ISO 5801:2007.
GB/T 19843-2005 Industrial fan - Performance testing of jet fans (ISO 13350:1999, IDT)
GB/T 25516-2010 Acoustics - Laboratory measurement procedures for ducted silencers and air - Terminal units loss, flow noise and total pressure loss (ISO 7235:2003, IDT)
GB/T 21231.1-2018 Acoustics - Measurement of airborne noise emitted and structure-borne vibration induced by small air-moving devices - Part 1: Airborne noise measurement (ISO 10302-1:2011, IDT)2)
Note: There is no technical difference between the referenced content of GB/T 21231.1-2018 and the referenced content of ISO 10302-1:2011.
GB/T 34877.1-2023 Industrial fans - Determination of fan sound power levels under standardized laboratory conditions - Part 1: General overview (ISO 13347-1:2004, IDT)
ISO 3740 Acoustics - Determination of sound power levels of noise sources - Guidelines for the use of basic standards
Note: GB/T 14367-2006, Acoustics - Determination of sound power levels of noise sources - Guidelines for the use of basic standards (ISO 3740:2000, MOD)
ISO 3741 Acoustics - Determination of sound power levels of noise sources using sound pressure - Precision methods for reverberation rooms
Note: GB/T 6881.1-2002, Acoustics - Determination of sound power levels of noise sources using sound pressure - Precision methods for reverberation rooms (ISO 3741:1999, IDT)
ISO 3743-1 Acoustics - Determination of sound power levels and sound energy levels of noise sources using sound pressure - Engineering methods for small movable sources in reverberant fields – Part 1: Comparison method for a hard-walled test room
Note: GB/T 6881.2-2017, Acoustics - Determination of sound power levels and sound energy levels of noise sources using sound pressure - Engineering methods for small movable sources in reverberant fields - Comparison method for a hard-walled test room (ISO 3741-1:2010, IDT)
ISO 3743-2 Acoustics - Determination of sound power levels of noise sources using sound pressure - Engineering methods for small, movable sources in reverberant fields - Part 2: Methods for special reverberation test rooms
Note: GB/T 6881.3-2002, Acoustics - Determination of sound power levels of noise sources-using sound pressure - Engineering methods for small, movable sources in reverberant field - Part 2: Methods for special reverberation test rooms (ISO 3741-2:1994, IDT)
ISO 5136 Acoustics - Determination of sound power radiated into a duct by fans and other air-moving devices - In-duct method
Note: GB/T 17697-2014, Acoustics - Determination of sound power radiated into a duct by fans and other air-moving devices - In-duct method (ISO 5136:2003, IDT)
ISO 5801 Industrial fans - Performance testing using standardized airways
Note: GB/T 1236-2017, Industrial fan - Performance testing using standardized airways (ISO 5801:2007, IDT)
ISO 7235 Acoustics - Laboratory measurement procedures for ducted silencers and air-terminal units - Insertion loss, flow noise and total pressure loss
Note: GB/T 25516-2010, Acoustics - Laboratory measurement procedures for ducted silencers and air - Terminal units loss, flow noise and total pressure loss (ISO 7235:2003, IDT)
ISO 10302-1 Acoustics - Measurement of airborne noise emitted and structure-borne vibration induced by small air-moving devices - Part 1: Airborne noise measurement3)
Note: GB/T21231.1-2018, Acoustics - Measurement of airborne noise emitted and structure-borne vibration induced by small air-moving devices - Part 1: Airborne noise measurement (ISO 10302-1:2011, IDT)
ISO 13349 Industrial fans - Vocabulary and definitions of categories
Note: GB/T 19075-2003, Industrial fans - Vocabulary and definitions of categories (ISO 13349:1999, IDT)
3 Terms and definitions
No terms and definitions are listed in this document.
4 Limitations on use
This document applies to industrial fans as defined by ISO 5801 and ISO 13349; it is limited to determining the airborne noise radiation of the specified installation and does not measure vibration or the sensitivity of the airborne sound radiation to the effects of vibration.
The size of the fan tested in accordance with this document is limited only by the actual location of the test arrangement; the size of the test fan and the aerodynamic performance will control the size of the chamber. (Smaller fans may be tested in accordance with this document or ISO10302-1, depending on the application).
The test arrangement in this document establishes the necessary laboratory conditions for successful testing; it is difficult to meet these requirements in the field and this document is not intended for field measurements; we caution the intended user that in these cases the acoustic environment may not meet the specified conditions and that additional acoustic system effects are likely to occur if the inlet and outlet conditions of the fan are less than ideal.
5 Field of application
This document deals with the determination of the acoustic performance of industrial fans and, in addition, may be used to determine the acoustic performance of fans combined with an ancillary device such as a roof cowl or damper or, where the fan is fitted with a silencer, the sound power resulting from the fan and silencer combination.
For low power fans (up to 3 kW) that could be run from a domestic power supply (single phase AC at a voltage not exceeding 250 V and a current not exceeding 16 A), reference should be made to the appropriate IEC standard for household and similar fans, IEC 60704-2-7.
For reverberant field tests, the size of equipment under test is limited to less than 2 % of the room volume. A test procedure is specified in Clause 9 of GB/T 19843-2005 for testing jet fans.
The test procedures specified in this document are intended principally for tests conducted using standardized test configurations and under specified environments and conditions, and may not be appropriate to site test conditions.
The fan installation conditions conform to the four categories of installation types specified in ISO 5801:
a) type A: free inlet, free outlet;
b) type B: free inlet, ducted outlet;
c) type C: ducted inlet, free outlet;
d) type D: ducted inlet, ducted outlet.
5.1 Noise source
The noise source is a fan. The noise measured may contain contributions from the fan drive and transmission.
5.2 Character of noise
Steady broad band with discrete frequency tones.
5.3 Uncertainty
Engineering grade as defined in ISO 3740.
5.4 Quantities to be measured
Sound pressure levels in one-third octave frequency bands at discrete microphone positions or on a prescribed path.
Fan aerodynamic performance indicators including rotational speed, fan pressure and flowrate.
6 Instrumentation
Full details of the instrumentation and its requirements are given in ISO 13347-1. This also details the requirements for the reference sound source which shall be used to qualify the test room and shall be the basis of the substitution method. To be used for these purposes, the reference sound source (RSS) shall be of an appropriate type, be calibrated accurately and be properly maintained.
7 Test method
The test method is based on a reference sound source (RSS) substitution for the determination of sound power. The reference documents for this method are ISO 3743-1 and ISO 3743-2.
Application of the test method requires that the fan to be tested be set in position in a test room, which is qualified according to the requirements of Annex A.
Once the test room has been qualified, sound pressure levels are recorded with the RSS operating. The fan is then operated without the RSS in operation at various performance points of interest for the given test speed, and the fan sound pressure levels are recorded. Since the sound power levels of the RSS are known, the substitution method is used to determine the sound power levels of the fan for each operating point.
