Standard No.:	GB/T 34877.1-2023
English Name:	Industrial fans—Determination of fan sound power levels under standardized laboratory conditions—Part 1: General overview
Chinese Name:	工业风机 标准实验室条件下风机声功率级的测定 第1部分：通用要求
Chinese Classification:	J72    Compressor and fan
Professional Classification:	GB    National Standard
Issued by:	SAMR; SAC
Issued on:	2023-12-28
Implemented on:	2023-12-28
Status:	valid
Language:	English
File Format:	PDF
Word Count:	18500 words
Price(USD):	555.0
Delivery:	via email in 1~3 business day

Industrial fans - Determination of fan sound power levels under standardized laboratory conditions - Part 1: General overview 1 Scope This document deals with the determination of the acoustic performance of industrial fans. It 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. 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 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 266 Acoustics - Preferred frequencies ISO 1000 SI units and recommendations for the use of their multiples and of certain other units 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 and sound energy levels of noise sources using sound pressure - Precision methods for reverberation test rooms Note: GB/T 6881.1-2002, Acoustics - Determination of sound power levels of noise sources using sound pressure - Precision methods for reverberation rooms (idt ISO 3741:1999) ISO 3742 Acoustics - Determination of sound power levels of noise sources - Precision methods for discrete-frequency and narrow-band sources in reverberation rooms 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 (idt ISO 3741-2:1994) ISO 3744 Acoustics - Determination of sound power levels and sound energy levels of noise sources using sound pressure - Engineering method in an essentially free field over a reflecting plane Note: GB/T 3767-2016, Acoustics - Determination of sound power levels and sound energy levels of noise sources using sound pressure - Engineering methods for an essentially free field over a reflecting plane (ISO 3744:2010, IDT) ISO 3745 Acoustics - Determination of sound power levels and sound energy levels of noise sources using sound pressure - Precision methods for anechoic rooms and hemi-anechoic rooms Note: GB/T 6882-2016, Acoustics - Determination of sound power levels and sound energy levels of noise sources using sound pressure - Precision methods for anechoic rooms and hemi-anechoic rooms (ISO 3745:2012, IDT) ISO 3746 Acoustics - Determination of sound power levels and sound energy levels of noise sources using sound pressure - Survey method using an enveloping measurement surface over a reflecting plane Note: GB/T 3768-2017, Acoustics - Determination of sound power levels and sound energy levels of noise sources using sound pressure - Survey method using an enveloping measurement surface over a reflecting plane (ISO 3746:2010) ISO 3747 Acoustics - Determination of sound power levels and sound energy levels of noise sources using sound pressure - Engineering/survey methods for use in situ in a reverberant environment Note: GB/T 16538-2008, Acoustics - Determination of sound power levels of noise sources using sound pressure - Comparison method in situ (ISO 3747:2000, IDT) ISO 5136 Acoustics - Determination of sound power radiated into a duct by fans and other air-moving devices - In-duct method ISO 5801 Fans - Performance testing using standardized airways Note: GB/T 1236-2017, Industrial fan - Performance testing using standardized airways (ISO 5801:2007, IDT) ISO 6926 Acoustics - Requirements for the performance and calibration of reference sound sources used for the determination of sound power levels Note: GB/T 4129-2003, Acoustics - Requirements for the performance and calibration of reference sound sources used for the determination of sound power levels (ISO 6926:1999, IDT) ISO 9614-1 Acoustics - Determination of sound power levels of noise sources using sound intensity - Part 1: Measurement at discrete points ISO 10302 Acoustics - Method for the measurement of airborne noise emitted by small air-moving devices ISO 13347-2:2004 Industrial fans - Determination of fan sound power levels under standardized laboratory conditions - Part 2: Reverberant room method ISO 13347-3 Industrial fans - Determination of fan sound power levels under standardized laboratory conditions - Part 3: Enveloping surface methods Note: GB/T 34877.3-2017, Industrial fans - Determination of fan sound power levels under standardized laboratory conditions - Part 3: Enveloping surface methods (ISO 13347-3:2004, IDT) ISO 13347-4 Industrial fans - Determination of fan sound power levels under standardized laboratory conditions - Part 4: Sound intensity method ISO 13349 Fans - Vocabulary and definitions of categories Note: GB/T 10123-2022, Industrial fans - Vocabulary and definitions of categories (ISO 13349:1999, IDT) ISO 13350 Industrial fans - Performance testing of jet fans Note: GB/T 19843-2022, Industrial fans - Performance testing of jet fans (ISO 13350:2015, IDT) 3 Terms, definitions, symbols and units 3.1 Terms and definitions For the purposes of this document, the non-acoustical terms and units defined in ISO 5801, ISO 13349 and ISO 1000, apply; the following acoustical definitions apply, they are taken from ISO 3470 to 3747 wherever possible and some have been expanded to fit the specific needs of this document. 3.1.1 inlet sound power level sound power level of a fan determined at the fan inlet in a specified test installation type, A, B, C or D 3.1.2 outlet sound power level sound power level of a fan determined at the fan outlet in a specified test installation, type A, B, C or D 3.1.3 casing sound power level sound power level radiated from a fan casing Note 1: If the fan drive is external to the fan casing, the casing sound power shall include the sound power generated by and radiated from the fan drive Note 2: When cataloguing a range of fans, it is not always possible to include the motor noise, as this will vary according to the power and type of motor selected. Motor noise may then be omitted, provided this fact is clearly stated. 3.1.4 frequency range of interest frequency range including octave bands with centre frequencies between 63 Hz and 8000 Hz and one-third octave bands with centre frequencies between 50 Hz and I0000 Hz Note: For special purposes, the frequency range may be extended at either end, provided that the test environment and instrument accuracy are satisfactory for use over the extended frequency range. For fans which radiate sound at predominantly high (or low) frequency, the frequency range of interest may be limited in order to optimise the test facility and procedures. 3.1.5 blade passage frequency BPF frequency of fan impeller blades passing a single fixed object Note: The blade passage frequency is calculated by the following formula 3.1.6 chamber enclosure used to regulate flow and absorb sound; it may also conform to air test chamber conditions outlined in ISO 5801 3.1.7 ducted fan fan having a duct connected to either its inlet or outlet, or both 3.1.8 fan inlet area A1 surface plane bounded by the upstream extremity of the air-moving device Note: The inlet area is, by convention, taken as the gross area in the inlet plane inside the casing.