1、1997 STANDARD for A I R-CON D IT1 ON I N G & R E F R I G E RAT1 ON INSTITUTE APPLICATION OF SOUND RATING LEVELS OF OUTDOOR UNITARY EQUIPMENT Standard 275 4301 NORTH FAIRFAX DRIVE ARLINGTON, VIRGINIA 22203 Copyright Air-Conditioning and Refrigeration Institute Provided by IHS under license with ARINo
2、t for ResaleNo reproduction or networking permitted without license from IHS-,-,-STD-AR1 275-ENGL 1797 D 0352120 0011080 TT2 IMPORTANT SAFETY RECOMMENDATIONS It is strongly recommended that the product be designed, constructed, assembled and installed in accordance with nationally recognized safety
3、requirements, appropriate for products covered by this standard. AM, as a manufacturers trade association, uses its best efforts to develop standards, employing state-of-the-art and accepted industry practices. However, AM does not certify or guarantee safety of any products, components or systems d
4、esigned, tested, rated, installed or operated in accordance with these standards or that any test conducted under its standards will be non-hazardous or free from risk. Price $15.00 (M) 330.00 (NM) Printed in U.S.A. Note: This Standard supersedes AR1 Standard 275-84. Bps d. Copyright 1997, by Air-co
5、nditioning and Refrigeration Institute Registered United States Patent and Trademark Ofce Copyright Air-Conditioning and Refrigeration Institute Provided by IHS under license with ARINot for ResaleNo reproduction or networking permitted without license from IHS-,-,-STD-AR1 275-ENGL 1797 0352320 OOLL
6、OBL 737 SECTION TABLE OF CONTENTS PAGE Section1 . Purpose . 1 Section2 . Scope 1 Section3 . Definitions 1 Section 4 . Procedure for Estimating A-Weighted SoundPressureLevels . 1 4.1 Introduction 1 4.2 Procedure for Estimating Sound Pressure Levels . Single Unit Installation 6 4.3 Procedure for Estim
7、ating Sound Pressure Levels . Multiple Unit Installation . 6 4.4 Points of Evaluation . 6 4.5 Examples 7 Section 5 . Recommended Practices . 11 Section 6 . Voluntary Conformance . 12 TABLES Table 1 . Application Factors for Estimating A-Weighted Sound Pressure Level . 2 Table 2 . Distance Factor . 5
8、 Table 3 . Values Used for Combining Numbers for Multi-Unit Installations 6 Table 4 . Expected Reduction with Barrier 12 APPENDICES Appendix A . References . Normative . 13 Appendix B . References . Informative 13 Copyright Air-Conditioning and Refrigeration Institute Provided by IHS under license w
9、ith ARINot for ResaleNo reproduction or networking permitted without license from IHS-,-,-Section 1. Purpose 1.1 Purpose. The purpose of this standard is to establish for outdoor unitary equipment: definitions, procedures for estimating A-Weighted sound pressure levels, and recommended application p
10、ractices. 1.1.1 Intent. This standard is intended for the guidance of the industry, including manufacturers, engineers, installers, contractors and users. 1.12 Review and Amendment. This standard is subject to review and amendment as technology advances. Section 2. Scope 2.1 Scope. Ibis standard app
11、lies to the outdoor sections of factory-made air-conditioning and heat pump equipment, as defiied in Section 3 and ARi Standard 210D40 when rated in accordance with ARI Standard 270. Section 3. Definitions STDaARI 275-ENGL 1777 D 0352320 OOLLO82 875 W AR1 STANDARD 275-97 APPLICATION OF SOUND RATING
12、LEVELS OF OUTDOOR UNITARY EQUIPMENT 3.1 D&nitbns. AU terms in this document will follow the standard industry definitions established in the current edition of ASHRAE Terminology of Heating, Ventilation, Air Conditioning and Refrigeration, unless otherwise defined in this section. 3.2 equipment rate
13、d in accordance with ARI Standard 270. Sound Rating Level. lat number which is assigned to 32.1 Standard Sound Rating Level. That number assigned to equipment rated at Standard Rating Conditions in accordance with ARI Standard 270. 33.2 Application Sound Rating Level. A number assigned to equipment
14、rated in accordance with ARI Standard 270 at conditions other than Standard Rating Conditions. 3.4 C-Weighted Sound Pressure Level. As used herein, the sound pressure level, as measured on the “C“ scale of a sound level meter manufactured in accordance with the provisions of ANSI Standard S1.4. 3.5
15、“Shall,“ “Should,“ “Recommended,“ or “It Is Recommended.“ “Shall,“ “should,“ “recommended,“ or “it is recommended“ shall be interpreted as follows: 35.1 Shall. Where “shall“ or “shall not“ is used for a provision specified, that provision is mandatory if compliance with the standard is claimed. 3.52
16、 Should, Recommended, or It Is Recommended. “Should,“ “recommended,“ or “it is recommended“ is used to indicate provisions which are not mandatory but which are desirable as good practice. Section 4. Procedure for Estimating A-Weighted Sound Pressure Levels 4.1 Introduction. AR1 Standard 270 establi
17、shes a method of rating outdoor unitary equipment in terms of AR1 Sound Rating Levels. The sound level of outdoor unitary equipment in various applications is dependent not only upon the ARI Sound Rating Level but also upon several significant factors related to the application of the equipment. The
18、se factors include equipment location, barrier shielding, sound path, and distance, as described in 4.1.1 through 4.1.4 and Table 1. Quantitative values for each of these factors are established to adjust the sound rating level. The summation of the sound rating levels and applied adjustments equal
19、the estimated A-Weighted sound pressure level. The rating method in ARI Standard 270 incorporates an adjustment which is applied in the presence of tones. This method may result in slightly higher predicted sound levels than measured sound levels when following the procedures described in this stand
20、ard. 4.1.1 Equipment Location Factor. This factor takes into consideration the effect of walls and other reflective surfaces adjacent to the equipment. Factors for typical equipment locations are given in Item 1, Table 1, and described with sketches. 33 A-Weighted Sound Pressure Level. As used herei
21、n, the sound pressure level, as measured on the “A“ scale of a sound level meter manufactured in accordance with the provisions of ANSI Standard S1.4. Copyright Air-Conditioning and Refrigeration Institute Provided by IHS under license with ARINot for ResaleNo reproduction or networking permitted wi
22、thout license from IHS-,-,- STD.ARI 275-ENGL 1777 0352320 001183 701 W AR1 STANDARD 275-97 1. Equipment Location Factor a. Equipment on ground or roof or in side of building wail with no adjacent reflective surface within b. Equipment on ground or roof or in side of building wall with a single adjac
23、ent reflective surface 10 ft. 3 m (d greater than 10 ft. 3 m) within 10 ft. 3 m (d less than 10 ft. 3 m) I Table 1. Application Factors for Estimating A-Weighted Sound Pressure Levels Factor Value 068 368 d in Side of Buiiding Single Reflective Surface On Ground or Roof I wall within 10 ft. 3 m of t
24、wo adjacent walls forming an inside comer (d less than 10 ft. 13 m to both surfaces) On Ground or Roof Two Adjacent Reflecting Surfaces In Side of Building Two Adjacent Reflecting Surfaces 2 Copyright Air-Conditioning and Refrigeration Institute Provided by IHS under license with ARINot for ResaleNo
25、 reproduction or networking permitted without license from IHS-,-,-STD*ARI 275-ENGL I997 9 0352320 0011084 b48 = AR1 STANDARD 275-97 1. Equipment Location Factor (continued) surface less than 15 ft. 4.6 m apart d. Equipment on ground or roof or in side of building wall and between two opposite refle
26、cting Factor Value 6dB 3 Copyright Air-Conditioning and Refrigeration Institute Provided by IHS under license with ARINot for ResaleNo reproduction or networking permitted without license from IHS-,-,-STD-AR1 275-ENGL 3777 m 0352320 0033085 584 m AR1 STANDARD 275-97 Table 1. Application Factors for
27、Estimating A-Weighted Sound Pressure Levels (Continued) 2. Barrier Shielding Factor (see sketches below). Sound reduction benefits can be gained when a solid structure obstructs the sound path. These structures could be: a. Comer of building b. Comer of flat roof and wail c. Parapet around flat roof
28、 d. Heavy continuous wail L = LI + & - D, where: 0.5 0.15 2 10.63 12 3.7 Factor Value 4dB 7dB 10 dB 12 dB 15 dB 17 dB LI + L, = Distance from equipment point of evaluation around barrier (Use minimum LI + L, value.) D = Direct distance from equipment to point of evaluation with no barrier. Determine
29、 D by layout sketch. 4 Copyright Air-Conditioning and Refrigeration Institute Provided by IHS under license with ARINot for ResaleNo reproduction or networking permitted without license from IHS-,-,- STD*ARI 275-ENGL 1777 0352120 OO11OBb 410 = 3. Sound Path Factor a. To a point of evaluation outdoor
30、s b. To room through open window(s) or open door(s) c. To room through closed single glass window(s) or door d. To room through closed double glass window(s) or solid wail (not illustrated) AR1 STANDARD 275-97 Factor Value O dB 10 dB 17 dB 23 dB 4.12 Barrier Shielding Factor. This factor accounts fo
31、r the sound reduction benefit of any solid sbucture that obstructs the line of sight (or sound) from the equipment location to the point of evaluation. Such a barrier may be the comer of a building, the edge of a roof, or a heavy wall of masonry, etc., built for the specific purpose of shielding noi
32、se from a unit to an area of concem. See Item 2, Table 1, for sketches and the normal barrier factors. 4.13 Sound Path Factor. This factor adjusts for the path of sound from the unit to the point of evaluation, which may be to the outdoors oniy, to a room through open windows, to a room through clos
33、ed windows, or through a wall. See Item 3, Table 1. 4.1.4 Distance Factor. The direct distance, D, from the equipment location to the point of evaluation is a very significant application factor in determining the estimated A-Weighted sound pressure levels resulting from the operation of outdoor equ
34、ipment in any installation. The distance factor is obtained from Table 2. Table 2. Distance Factor ft. 4 5 6 7 8 9 10 15 20 25 30 40 50 60 70 80 90 100 125 150 175 200 400 rm1 1.2 1.5 1.8 2.1 2.4 2.7 3 .O 4.6 6.1 7.6 9.1 12.2 15.2 18.3 21.3 24.4 27.4 30.5 38.1 45.7 53.3 61.0 122.0 Factor Value dB) 9
35、.5 11.5 13.0 14.5 15.5 16.5 17.5 21.0 23.5 25.5 27.0 29.5 31.0 33.0 34.5 35.5 36.5 37.5 39.5 41.0 42.5 43.5 49.5 ,-.- Copyright Air-Conditioning and Refrigeration Institute Provided by IHS under license with ARINot for ResaleNo reproduction or networking permitted without license from IHS-,-,- STD-A
36、R1 275-ENGL 1777 D 0352120 0011087 357 AR1 STANDARD 275-97 4.2 Procedure for Estimating Sound Pressure Levels - Single Unit Installation. The basic procedure for estimating A-Weighted sound pressure levels at a given point of evaluation consists of combining the sum of the application and evaluation
37、 factors with the Sound Rating Level for the equipment: Sound Rating Level from ARI 270 + Equipment Location Factor - Barrier Sbielding Factor - Sound Path Factor - Distance Factor Estimated A-Weighted Sound Ressure Level dB* 43 Procedure for Estimating Sound Levels-Multiple Unit Installation. Estim
38、ated sound levels for multiple unit instailations at any point of interest can be determined by combining the effects of each unit at the point of interest. The procedure for multi-unit installations follows that used for single units except for the additional procedure used to combine numbers. 43.1
39、 as follows: The combined level for all units is determined 1. 2. 3. 4. 5. Detede the numerical difference between the largest and next largest levels. Using Table 3, find the proper value and add it to the larger number. This combines the two largest numbers. Determine the numerical difference betw
40、een this combined number and the third largest level. Again, using Table 3, find the proper value and add it to the combined number. Continue this combining procedure until the value to be added from Table 3 becomes 0.0 or until all numbers have been combined. The resulting single number represents
41、the effect of all units at the point of evaluation. (See Example 4.5.4) I Table 3. Values Used for Combining Numbers for Multi-Unit Installations I Difference Between Value to be Added to Larger Number (dB) 0.0 to 0.5 1.0 to 1.5 2.0 to 3.0 3.5 to 5.0 5.5 to 7.0 greater than 7.0 3 .O 2.5 2.0 1.5 1 .o
42、 0.0 4.4 Points of Evaluation. The calculation procedures described in 4.2 and 4.3 should be made for each area of concern to evaluate the instailation from an acoustic standpoint (see 4.5, Examples). Measured A-Weighted sound pressure levels shail be within f 5 dB of estimated levels when backgroun
43、d levels are at least 5 dB below measured values. This estimation error accounts for the effect of the tone adjustment applied during the rating procedure of ARJ Standard 270, as weil as inaccuracies in the estimation procedure itself. To obtain the background level, readings shall be made with the
44、unit not operating. The effects of enviromentai conditons on estmated sound levels are not included in this procedure. * Rounded to the nearest whole dB value. 6 Copyright Air-Conditioning and Refrigeration Institute Provided by IHS under license with ARINot for ResaleNo reproduction or networking p
45、ermitted without license from IHS-,-,- STD-AR1 275-ENGL 1777 9 0352320 OC11088 293 Unit Sound Rating Level (ART Standard 270) Equipment Location Factor (Table 1, Item 1) Add Lines 1 and 2 Barrier Shielding Factor (Table 1, Item 2) Sound Path Factor (Table 1, Item 3) Distance Factor (Table 2) Add Lin
46、es 4,5 and 6 AR1 STANDARD 275-97 68 68 3 3 71 71 O O O O 31 21 31 21 45 Examples. Estimated A-Weighted Sound Pressure Level (Subtract Line 7 from Line 3) 45.1 Installation with No Barriers and One Reflective Surface. 40 50 33 l4.6 m Sound Rating Level of Unit - 68 dB Line 1 2 3 4 5 6 7 8 Distance fr
47、om equipment to evaluation point 1. 47 ft. r14.3 m 2. 15 ft. 4.6 m 3. 35 ft. r10.7 m Evaluation Points 68 3 71 O 10 38 7 Copyright Air-Conditioning and Refrigeration Institute Provided by IHS under license with ARINot for ResaleNo reproduction or networking permitted without license from IHS-,-,-STD
48、-AR1 275-ENGL 1777 0352320 0011087 12T AR1 STANDARD 27197 Line 1 2 3 4 5 6 7 8 9 453 Installation wirh Barriers. Distance from equipment 2. 41 ftJ12.5 m to evaluation point 3. 20 ft. 6.1 m 1 2 Equipment Location Factor (Table 1, Item 1) 3 3 Add Lines 1 and 2 73 73 Barrier Shielding Factor (Table 1,
49、Item 2) O 7 Sound Path Factor (Table 1, Item 3) O 10 Unit Sound Rating Level (ARI Standard 270) 70 70 Distance Factor (Table 2) 28 29.5 Add Lines 4,5 and 6 28 46.5 Estimated A-Weighted Sound Pressure Level 45 26.5 (Subtract Line 7 from Line 3) Estimated A-Weighted Sound Pressure Level Rounded to 45 27 Nearest Whole Number a2
