AMCA-300-2005.pdf

The International Authority on Air System Components This standard has been approved by AMCA International, and will be proposed as an American National Standard. AMCA Standard 300-05 Sound Testing of Fans Reverberant Room Method for AMCA Standard 300 - 05 Reverberant Room Method for Sound Testing of Fans AIR MOVEMENT AND CONTROL ASSOCIATION INTERNATIONAL 30 WEST UNIVERSITY DRIVE ARLINGTON HEIGHTS, IL 60004-1893 U.S.A. PHONE: (847) 394-0150 fax: (847) 253-0088 web: WWW.AMCA.ORG ii © 2005 by Air Movement and Control Association International, Inc. All rights reserved. Reproduction or translation of any part of this work beyond that permitted by Sections 107 and 108 of the 1976 United States Copyright Act without the permission of the copyright owner is unlawful. Requests for permission or further information should be addressed to the Executive Director, Air Movement and Control Association International, Inc. Forward/Authority AMCA Standard 300-05 was adopted by the membership of the Air Movement and Control Association International, Inc. on 30 July 2005. The effective date of this standard is 01 November 2005. Tung Nguyen (Chair)Emerson Ventilation Products Dr. John CermakAcme Engineering it is the objective cause of hearing. Sound pres- sure level is described mathematically as a logarithmic quantity derived from sound pressure. The unit of sound pressure level is the decibel, referenced to a base of 20 micropascals, or 20 microbar. The sound pressure level at any given point in space depends on the distance between the source and the receiver, reflection if in an enclosed room, proximity of the source to other sound sources, etc. Sound in a room is the result of one or more active sound power sources within that room. Sound power is the total sound energy radiated per unit time. Sound power level is described mathematically as a logarithmic quantity derived from the sound power. The unit of sound power level is the decibel referenced to 1 picow- att (1.0E-12 watt). Sound power levels determined through use of this standard are useful for comparison between fans and in acoustical design. Since sound power is independent of acoustic environment, two or more fans pro- posed for a specific aerodynamic performance condition may be evaluated by comparison to determine whether one is more suitable for an application than another. Moreover, fan sound power levels establish an accurate base for esti- mating the acoustical outcome of the fan installation in terms of sound pressure levels. Asuccessful estimate of sound pressure levels requires extensive informa- tion on the fan and the environment in which it is to be located. It is often advantageous for the fan equipment user to employ acoustical consul- tation to ensure that all factors that affect the final sound pressure levels are con- sidered. Additional information on the complexity of this situation may be found in other documents available elsewhere. ContentsPage 1. Scope . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .1 2. Normative references . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .1 3. Definitions / units of measure / symbols . . . . . . . . . . . . . . . . . . . . . . . . . . . . .1 3.1 Definitions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .1 3.2 Symbols . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .3 4. Instruments / methods of measurement . . . . . . . . . . . . . . . . . . . . . . . . . . . . .3 4.1 Sound level meter . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .3 4.2 Microphone system . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .3 4.3 Frequency analyzer and weighting system . . . . . . . . . . . . . . . . . . . . . . .3 4.4 Data recording equipment . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .3 4.5 Reference sound source (RSS) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .3 4.6 Test method . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .5 4.7 Accuracy of results . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .5 5. Equipment / setups . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .5 5.1 Reverberant room . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .5 5.2 Setup categories . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .5 5.3 Aerodynamic performance . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .5 5.4 Mounting methods . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .6 5.5 Duct length . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .6 5.6 Microphone travel . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .6 5.7 Calibration of system . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .6 5.8 Equations . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .10 6. Observations and conduct of test . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .10 6.1 Observations . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .10 6.2 Information to be recorded . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .11 7. Calculations . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .11 7.1 Background correction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .12 7.2 Sound power level (Lw) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .12 8. Results and report . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .12 8.1 Test subject . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .12 8.2 Laboratory and instruments . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .13 8.3 Acoustical data . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .13 Annex A (normative) Room qualification: full and one-third octave . . . . . . . . . .15 A.1 General . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .15 A.2 Instruments and quipment . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .15 A.3 Test procedure . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .15 v A.4 Computation procedure . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .15 A.5 Qualification . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .16 Annex B (informative) Room qualification: pure tones / narrow-band . . . . . . .17 B.1 General . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .17 B.2 Instruments and equipment . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .17 B.3 Test procedure . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .17 B.4 Computation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .18 B.5 Qualification . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .18 Annex C (informative) Uncertainties analysis . . . . . . . . . . . . . . . . . . . . . . . . . . .21 C.1 Definitions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .21 C.2 Uncertainties . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .21 C.3 Room response . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .21 C.4 Fan operating points . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .23 C.5 Instrument error . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .23 C.6 Reference sound source (RSS) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .24 C.7 Estimated standard deviation for determination of sound power levels 24 C.8 Duct end reflection corrections . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .24 C.9 Octave band vs. One-third octave band . . . . . . . . . . . . . . . . . . . . . . . .25 C.10 Accuracy of the 63 hz octave band . . . . . . . . . . . . . . . . . . . . . . . . . . . .26 Annex D (informative) Alternative procedure for reference sound source calibra- tion . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .27 D.1 General . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .27 D.2 Equipment and facilities . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .27 D.3 Qualification . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .27 D.4 Procedure . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .27 D.5 RSS sound power levels . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .28 Annex E (normative) Duct end reflection correction . . . . . . . . . . . . . . . . . . . . . .29 E.1 General . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .29 E.2 End reflection curves . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .29 Annex F (informative) Filter-weighted measurements . . . . . . . . . . . . . . . . . . . .34 Annex G (informative) Radiation of sound by fan casing . . . . . . . . . . . . . . . . . .35 G.1 General . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .35 G.2 Instruments and equipment . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .35 G.3 Setup and test . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .35 G.4 Observations and calculations . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .35 Annex H (informative) Total fan sound testing with attached ducts . . . . . . . . . .36 Annex J (informative) References . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .38 vi AMCA INTERNATIONAL INC. AMCA 300-05 REVERBERANT ROOM METHOD FOR SOUND TESTING OF FANS 1. Scope This standard applies to fans of all types and sizes. This standard is limited to the determination of airborne sound emission for the specified setups. Vibration is not measured, nor is the sensitivity of airborne sound emission to vibration effects determined. The size of a fan that can be tested in accordance with this standard is limited only by the practical aspects of the test setups. Dimensional limitations, test subject dimensions, and air performance will control the test room size and power and mounting requirements for the test subject. The test setup requirements in this standard establish the laboratory conditions necessary for a successful test. Rarely will it be possible to meet these requirements in a field situation. This standard is not intended for field measurements. 2. Normative references The following standards contain provisions that, through specific reference in this text, constitute provisions of this American National Standard. At the time of publication the editions indicated were valid. All standards are subject to revision, and parties to agreements based on this American National Standard are encouraged to investigate the possibility of applying the most recent editions of the standards listed below. ANSI/AMCA 210-99 / ANSI/ASHRAE 51-1999 Laboratory Methods of Testing Fans for Aerodynamic Performance Rating, Air Movement and Control Association International, Inc., 30 W. University Drive, Arlington Heights, IL 60004-1893 U.S.A, 1999 ANSI S1.4-1983; S1.4A-1985 Specification for Sound Level Meters, Acoustical Society of America, 120 Wall St., 32nd Floor, New York, NY 10005-3993 U.S.A., 1985 (AMCA #2315-83-AO) ANSI S1.11-2004 Specification for Octave Band and Fractional Octave Band Analog and Digital Filters, Acoustical Society of America, 120 Wall St., 32nd Floor, New York, NY 10005-3993 U.S.A., 1986 (AMCA #1727-86-AO) ANSI S1.40-1984 Standard Specification for Acoustical Calibrators, Acoustical Society of America, 120 Wall St., 32nd Floor, New York, NY 10005-3993 U.S.A., 1984 (AMCA #1895-84-AO) ANSI S12.5-1990 Requirements for the Performance and Calibration of Reference Sound Sources, Acoustical Society of America, 120 Wall St., 32nd Floor, New York, NY 10005- 3993 U.S.A., 1990 (AMCA #1863-90-AO) ANSI S12.12-1992 Engineering Method for the Determination of Sound Power Levels of Noise Sources Using Sound Intensity, Acoustical Society of America, 120 Wall St., 32nd Floor, New York, NY 10005-3993 U.S.A., 1992 (AMCA #1850-92-AO) ANSI/IEEE/ASTM SI 10-1997 Standard for Use of the International System of Units (SI): The Modern Metric System, Institute of Electrical and Electronic Engineers, 345 east 47th Street, New York, NY 10017 U.S.A., 1997 (AMCA #2924-97- AO) 3. Definitions / units of measure / symbols 3.1 Definitions 3.1.1 Blade Passage Frequency (BPF): The frequency of fan impeller blades passing a single fixed object, per the following formula: BPF = (number of blades)(fan rotational speed, rev/min) / 60, in Hz. 3.1.2 Chamber: An enclosure used to regulate airflow and absorb sound; it may also conform to air test chamber conditions given in ANSI/AMCA 210. 3.1.3 Decibel (dB): A dimensionless unit of AMCA 300-05 2 level in logarithmic terms for expressing the ratio of a power, or power-like, quantity to a similar reference quantity. (See 3.1.13 and 3.1.14) 3.1.4 Ducted Fan: A fan having a duct connected to either its inlet, its outlet, or to both. 3.1.5 End Reflection: A phenomenon that occurs whenever sound is transmitted across an abrupt change in area, such as at the end of a duct in a room. When end reflection occurs some of the sound entering the room is reflected back into the duct and does not escape into the room. 3.1.6 Frequency: The number of times in one second that a periodic function repeats itself. 3.1.7 Informative: A term that indicates that the referenced material is provided as advice to the reader but does not constitute a mandatory requirement. 3.1.8 Non-ducted Fan: A fan without a duct connected to either its inlet or outlet. 3.1.9 Normative: A term that indicates that the referenced material, if applied, constitutes a mandatory requirement. 3.1.10 Octave Band: The inter