AHRI 270-2008 Sound Performance Rating of Outdoor Unitary Equipment.pdf

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1、 2008 Standard for Sound Performance Rating of Outdoor Unitary Equipment ANSI/AHRI Standard 270 (Formerly ARI Standard 270) Price $10.00 (M) $20.00 (NM) Copyright 2008, by Air-Conditioning, Heating, and Refrigeration Institute Printed in U.S.A. Registered United States Patent and Trademark Office IM

2、PORTANT SAFETY DISCLAIMER AHRI does not set safety standards and does not certify or guarantee the safety of any products, components or systems designed, tested, rated, installed or operated in accordance with this standard/guideline. It is strongly recommended that products be designed, constructe

3、d, assembled, installed and operated in accordance with nationally recognized safety standards and code requirements appropriate for products covered by this standard/guideline. AHRI uses its best efforts to develop standards/guidelines employing state-of-the-art and accepted industry practices. AHR

4、I does not certify or guarantee that any tests conducted under its standards/guidelines will be non-hazardous or free from risk. Note: This standard supersedes ARI Standard 270-95 and differs in the following ways. a. The single number overall A-weighted tone corrected sound power level rating has b

5、een replaced by ratings comprised of Sound Power Levels expressed in decibels and a numeric Sound Quality Indicator: Octave band Sound Power Levels, dB (125 Hz to 8,000 Hz are required, 63 Hz is optional) Overall A-Weighted Sound Power Level, dB (100 Hz to 10,000 Hz is required, 50 Hz to 10,000 Hz i

6、s optional) Sound Quality Indicator (SQI) per AHRI Standard 1140 (optional) One-third octave band Sound Power Levels, dB (optional) b. The frequency range of interest has been expanded to include the 63 Hz Octave Band (comprised of the 50, 63 and 80 Hz One-Third Octave Bands) as optional data. c. Al

7、l Sound Power Levels are determined from one-third octave band sound pressure level measurements. d. In addition to sound ratings for the complete unit, the scope of the ratings has been expanded to optionally include sound levels for “fan(s) only” operation as well. e. This standard references AHRI

8、 Standard 220 for reverberation room qualification and testing replacing ANSI Standard S12.31 and ANSI Standard S12.32, which were withdrawn. TABLE OF CONTENTS SECTION PAGE Section 1. Purpose 1 Section 2. Scope .1 Section 3. Definitions.1 Section 4. Test Requirements 2 Section 5. Rating Requirements

9、 .4 Section 6. Minimum Data Requirements for Published Ratings .6 Section 7. Marking and Nameplate Data .6 Section 8. Conformance Conditions 6 TABLES Table 1. One-Third Octave Band Numbers and A-Weighting Factors .5 APPENDICES Appendix A. References Normative 7 Appendix B. References Informative 7 A

10、ppendix C. Example Calculation of Octave Band Sound Power Levels Informative 8 Appendix D. Example Calculation of A-Weighted Sound Power Levels Informative .9 Appendix E. Expected Size of Measurement Errors Informative .10 TABLES FOR APPENDICES Table C1. Example Calculation of Octave Band Sound Powe

11、r Levels, Lwi8 Table D1. Example Calculation of A-Weighted Sound Power Levels, LwA9 Table E1. Maximum Standard Deviations of Sound Power Level Reproducibility Determined in Accordance with this Standard .10 ANSI/AHRI STANDARD 270-2008 1 SOUND PERFORMANCE RATING OF OUTDOOR UNITARY EQUIPMENT Section 1

12、. Purpose 1.1 Purpose. The purpose of this standard is to establish for outdoor unitary equipment: definitions; test requirements; rating requirements; minimum data requirements for Published Ratings; marking and nameplate data; and conformance conditions. 1.1.1 Intent. This standard is intended for

13、 the guidance of the industry, including manufacturers, engineers, installers, contractors and users. 1.1.2 Review and Amendment. This standard is subject to review and amendment as technology advances. Section 2. Scope 2.1 Scope. This standard applies to the outdoor sections of factory-made air-con

14、ditioning and heat pump equipment as defined in AHRI Standard 210/240 or AHRI Standard 340/360 (cooling capacity ratings of equal to or less than 135,000 Btu/h 40.0 kW). Section 3. Definitions All terms in this document shall follow the standard industry definitions established in the current editio

15、n of ASHRAE Terminology of Heating, Ventilation, Air-Conditioning and Refrigeration, unless otherwise defined in this section. 3.1 Air-Source Unitary Heat Pump. One or more factory-made assemblies which normally include an indoor conditioning coil(s), compressor(s), and outdoor coil(s), including me

16、ans to provide a heating function. When such equipment is provided in more than one assembly, the separated assemblies shall be designed to be used together, and the requirements of rating outlined in the standard are based upon the use of matched assemblies. 3.1.1 Functions. They shall provide the

17、function of air heating with controlled temperature and may include the functions of air-cooling, air-circulating, air-cleaning, dehumidifying or humidifying. 3.2 Hertz (Hz). A unit of frequency equal to one cycle per second. 3.3 Octave Band. A band of sound covering a range of frequencies such that

18、 the highest is twice the lowest. The Octave Bands used in this standard are those defined in ANSI Standard S1.11. 3.4 One-Third Octave Band. A band of sound covering a range of frequencies such that the highest frequency is the cube root of two times the lowest. The One-Third Octave Bands used in t

19、his standard are those defined in ANSI Standard S1.11. 3.5 Published Rating. A statement of the assigned values of those performance characteristics, under stated rating conditions, by which a unit may be chosen to fit its application. These values apply to all units of like nominal size and type (i

20、dentification) produced by the same manufacturer. As used herein, the term Published Rating includes the rating of all performance characteristics shown on the unit or published in specifications, advertising or other literature controlled by the manufacturer, at stated rating conditions. 3.5.1 Appl

21、ication Rating. A rating based on tests performed at application Rating Conditions (other than Standard Rating Conditions). ANSI/AHRI STANDARD 270-2008 2 3.5.2 Standard Rating. A rating based on tests performed at Standard Rating Conditions. 3.6 Rating Conditions. Any set of operating conditions und

22、er which a single level of performance results, and which cause only that level of performance to occur. 3.6.1 Standard Rating Conditions. Rating Conditions used as the basis of comparison for performance characteristics. 3.7 Reference Sound Source (RSS). A portable, aerodynamic sound source that pr

23、oduces a known stable broadband sound. 3.8 “Shall” or “Should”. “Shall” or “should” shall be interpreted as follows: 3.8.1 Shall. Where “shall” or “shall not” is used for a provision specified, that provision is mandatory if compliance with the standard is claimed. 3.8.2 Should. “Should” is used to

24、indicate provisions which are not mandatory but which are desirable as good practice. 3.9 Sound Power Level, Lw. Ten times the logarithm to the base ten of the ratio of the sound power radiated by the source to a reference sound power, expressed in decibels (dB). The reference sound power used in th

25、is standard is 1 picowatt (pW). 3.9.1 A-Weighted Sound Power Level, LwA. The logarithmic summation of A-Weighted, one-third octave band Sound Power Levels. 3.10 Sound Pressure Level, Lp. Twenty times the logarithm to the base ten of the ratio of a given sound pressure to a reference sound pressure o

26、f 20 Pa, expressed in decibels (dB). 3.11 Sound Quality Indicator (SQI). The calculated metric determined when following the procedure contained in ARI Standard 1140 for quantifying sound quality whereby measured sound levels are weighted to adjust for psychoacoustic sensitivity to frequency distrib

27、ution and any discreet tones which may be present and then converted to a single number Sound Quality Indicator. 3.12 Unitary Air-Conditioner. One or more factory-made assemblies which normally include an evaporator or cooling coil(s), compressor(s) and condenser(s). Where such equipment is provided

28、 in more than one assembly, the separated assemblies are to be designed to be used together, and the requirements of rating outlined in this standard are based upon the use of these assemblies in operation together. 3.12.1 Functions. Either alone or in combination with a heating plant, the functions

29、 are to provide air-circulation, air cleaning, cooling with controlled temperature and dehumidification, and may optionally include the function(s) of heating and/or humidifying. Section 4. Test Requirements 4.1 Test Requirements. All standard sound power level ratings shall be determined by tests c

30、onducted in a reverberation room meeting the requirements of and qualified in accordance with ARI Standard 220 except as noted within the body of this standard. Sound Power Levels for the unit under test shall be determined per ARI Standard 220. A Reference Sound Source (RSS) shall be used that meet

31、s the performance requirements of and is calibrated per ARI Standard 250. 4.2 Test Conditions. Standard sound ratings shall be based on sound tests conducted with the unit operating at rated voltage (V), phase, and frequency (Hz) as specified on the unit nameplate and measured at the service connect

32、ion. Sound tests shall be conducted as prescribed below: ANSI/AHRI STANDARD 270-2008 3 4.2.1 In the first step, the sound measurements shall be made with the equipment operating at the ARI standard thermal rating condition in ARI Standards 210/240 and 340/360. 4.2.2 In the optional second step, the

33、compression equipment shall be turned off and sound readings taken with only the fan(s) operating. During this step, the temperature of the ambient air entering the unit shall be within 2.0 F 1.1 C of the temperature measured during compressor operation. 4.3 Data to be Taken. Sound data taken shall

34、be per ARI Standard 220 in One-Third Octave Bands (100 Hz to 10,000 Hz are required, 50 Hz to 80 Hz are optional) in accordance with the procedure specified above for the type of test being conducted. 4.4 Air Velocity at Measurement Positions. Sound measurements shall not be made when the air veloci

35、ty over the microphone exceeds 1,100 ft/min 5.6 m/s. A foam windscreen shall be installed on the microphone which shall not affect the microphone response by more than 1 dB for frequencies of 20 to 4,000 Hz or 1.5 dB for frequencies above 4,000 Hz. 4.5 Unit Installation. The unit under test shall be

36、 located within the reverberation room as specified in ARI Standard 220. Where applicable, unit supply and return ducting shall be lagged to prevent sound radiating from them (refer to ARI Standard 260 for guidance in duct construction). In the case of wall-mounted equipment, the mounting wall shall

37、 be of heavy masonry or equivalent construction, or an auxiliary mounting platform shall be provided to minimize wall vibration effects. Care must be taken to minimize the noise radiating from the connecting refrigerant piping on split systems. 4.6 Unit Operation. The unit under test shall operate a

38、s specified below. 4.6.1 Electrical Characteristics. Tests shall be performed at the nameplate rated voltage, phase, and frequency at the unit service connection. For units with dual nameplate voltage ratings, standard sound tests shall be performed at both voltages. The higher of the two ratings ob

39、tained shall be the ARI standard sound rating or both ratings shall be published. 4.6.2 Outdoor-Side Air Quantity. All tests shall be made at the outdoor-side air quantity specified by the manufacturer where the fan drive is adjustable, or, where the fan drive is direct-connected, they shall be dete

40、rmined at the outdoor air quantity inherent to the unit when operated with all of the air resistance elements associated with inlet louvers and any duct work and attachments normally supplied as part of the unit. Once established, the outdoor air circuit shall remain unchanged for all tests prescrib

41、ed herein, except for the reduced ambient conditions operation (Refer to 4.6). 4.6.3 Unit Operation Requirements. All components required to produce the standard rating capacity under ARI Standard 210/240 or ARI Standard 340/360 shall be operated while data is being taken and the test conditions sha

42、ll be identical to the standard (cooling) condition temperatures specified in ARI Standard 210/240 or ARI Standard 340/360. For convenience, the test temperatures in these standards are: Air temperatures entering indoor side: 80.0 F 26.7 C dry bulb, 67.0 F 19.4 C wet bulb. Air temperature entering o

43、utdoor side: 95.0 F 35.0 C dry bulb (and 75.0 F 23.9 C wet bulb when condensate is rejected to the air stream). 4.6.4 Indoor Side Loading. The indoor side loading shall be maintained as follows: 4.6.4.1 Single-Package Units. Tests shall be conducted at the air quantity used for standard rating tests

44、 as specified in ARI Standard 210/240 or ARI Standard 340/360. 4.6.4.2 Split-System Units. The indoor refrigeration load shall be maintained at the values required to duplicate those found under standard rating tests as specified in ARI Standard 210/240 or ARI Standard 340/360. ANSI/AHRI STANDARD 27

45、0-2008 4 4.6.5 Test Condition Tolerances. During sound rating tests, the equipment operating conditions shall not deviate from the specified operating conditions by more than the following tolerances: Air Temperature 2.0F 1.1C When the indoor-side loading is simulated by a method not requiring air,

46、the following tolerances apply: Suction gas temperature at compressor* 5.0 F 2.8 C Evaporator pressure 2.0 psi 14 kPa * Applicable only when the suction gas superheat is at least 10 F 5.6 C in the equivalent Standard Rating test specified in the ARI standard for the equipment being tested. Section 5

47、. Rating Requirements 5.1 Introduction. The outdoor sound rating shall be for the complete unit operating and optionally for the unit operating with “fan(s) only.” The ratings shall be comprised of: Octave band Sound Power Levels, (Lw), dB (125 Hz to 8,000 Hz are required, 63 Hz is optional) Overall

48、 A-Weighted Sound Power Level, (LwA), dB (100 Hz to 10,000 Hz are required, 50 Hz to 10,000 Hz are optional) Sound Quality Indicator (SQI) per ARI Standard 1140 (optional) One-third octave band Sound Power Levels, dB (optional) 5.2 Determination of Outdoor One-Third Octave Band Sound Power Levels. T

49、hese unit levels shall be determined per ARI Standard 220. The unit under test shall be installed as specified by Section 4.5 of this standard. 5.2.1 Octave Band Sound Power Level Calculations. Octave band sound power level calculations shall be made per Equation 1. ( )wj3i0.1 Lwij=3i-2L = 10 log 101 Where: wiL= Sound Power Level in the ithOctave Band wjL = Sound Power Level in the jthOne-Third Octave Band j = An integer number lying within the range (3i 2) and 3i, and which identifies the th