AHRI 881 SI-2011 Performance Rating of Air Terminals (Incorporates Addendum 1 06 2012).pdf

1、 2011 Standard for Performance Rating of Air Terminals Approved by ANSI on December 6, 2012 ANSI/AHRI Standard 881 (SI) with Addendum 1 Price $10.00 (M) $20.00 (NM) Copyright 2011, by Air-Conditioning, Heating, and Refrigeration Institute Printed in U.S.A. Registered United States Patent and Tradema

2、rk Office ANSI/AHRI STANDARD 881 (SI)-2011 WITH ADDENDUM 1, PERFORMANCE RATING OF AIR TERMINALS June 2012 Addendum 1 (dated June 2012) of ANSI/AHRI Standard 881 (SI)-2011 modifies AHRI Standard 880 (SI)-2011 as follows. The following changes have been incorporated (additions are shown by shading and

3、 deletions are shown by strikethroughs) into the second sentence of Section 6.1.3.4 of the already published 2011 version of ANSI/AHRI Standard 881 (SI)-2011. Also, ANSI/AHRI Standard 260-2011 has been added to Appendix A. The changes include: 6.1.3.4 Discharge Sound Power. To determine discharge So

4、und Power Level, the Air Terminal shall be installed in accordance with Figures 9.1 through 9.3 of ASHRAE Standard 130. The test duct shall be flush with the inside wall of the reverberation room and shall be constructed in accordance with Section 4.5.1 of ANSI/AHRI Standard 260. Alternatively, for

5、Integral Diffuser Air Terminals, the discharge Sound Power Level may be determined in accordance with Figure 9.4 of ASHRAE Standard 130. For Modulating Diffuser Air Terminals, the discharge Sound Power Level shall be determined in accordance with Figures 5 and 6 of ANSI/ASHRAE Standard 70. APPENDIX

6、A. REFERENCES NORMATIVE A1 Listed here are all standards, handbooks, and other publications essential to the formation and implementation of the standard. All references in this appendix are considered as part of this standard. A1.1 AHRI Standard 220-2007, Reverberation Room Qualification and Testin

7、g Procedures for Determining Sound Power of HVAC Equipment, 2007, Air-Conditioning, Heating, and Refrigeration Institute, 2111 Wilson Boulevard, Suite 500, Arlington, VA 22201, U.S.A. A1.2 AHRI Standard 410-2001, Forced Circulation Air-Cooling and Air-Heating Coils, 2001, Air-Conditioning, Heating,

8、and Refrigeration Institute, 2111 Wilson Blvd., Suite 500, Arlington, VA 22201, U.S.A. A1.3 AHRI Standard 440-2008, Performance Rating of Room Fan-Coils, 2008, Air-Conditioning, Heating, and Refrigeration Institute, 2111 Wilson Blvd., Suite 500, Arlington, VA 22201, U.S.A. A1.4 AHRI Standard 885-200

9、8 (with Addendum 1 dated March 2011) , Procedure for Estimating Occupied Space Sound Levels in the Application of Air Terminals and Air Outlets, 2008, Air-Conditioning, Heating, and Refrigeration Institute, 2111 Wilson Blvd., Suite 500, Arlington, VA 22201, U.S.A. A1.5 ANSI/AHRI Standard 260-2011, S

10、ound Rating of Ducted Air Moving and Conditioning Equipment, 2011, Air-Conditioning, Heating, and Refrigeration Institute, 2111 Wilson Boulevard, Suite 500, Arlington, VA 22201, U.S.A. A1.6 ANSI/ASHRAE 70-2006 (R2011), Method of Testing for Rating the Performance of Air Outlets and Inlets, 2006, Ame

11、rican Society of Heating, Refrigerating, and Air-Conditioning Engineers, Inc., 1791 Tullie Circle N.E., Atlanta, GA 30329, U.S.A. A1.7 ASHRAE 130-2008, Methods of Testing for Rating Ducted Air Terminal Units, 2008, American Society of Heating, Refrigerating, and Air-Conditioning Engineers, Inc., 179

12、1 Tullie Circle N.E., Atlanta, GA 30329, U.S.A. A1.8 ASHRAE Terminology of Heating, Ventilation, Air Conditioning, classifications; test requirements; rating requirements; minimum data requirements for Published Ratings; marking and nameplate data; and conformance conditions. 1.1.1 Intent. This stan

13、dard is intended for 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 air control devices used

14、 in air distribution systems. These devices provide control of air volume with or without temperature control by one or more of the following means and may or may not include a fan: 2.1.1 Fixed or adjustable directional vanes (i.e. Bypass Air Terminal) 2.1.2 Pressure dependent volume dampers or valv

15、es (including air induction nozzles and Dampers) 2.1.3 Pressure compensated volume dampers or valves (including air induction nozzles and Dampers) 2.1.4 Integral heat exchange 2.1.5 On/off fan control 2.1.6 Variable speed fan control 2.1.7 Integral Diffuser Air Terminals 2.2 Exclusions. This standar

16、d does not apply to registers, diffusers and grilles or to products specifically covered by AHRI Standard 410 or AHRI Standard 440. Section 3. Definitions All terms in this document follow the standard industry definitions in the current edition of ASHRAE Terminology of Heating, Ventilation, Air Con

17、ditioning, and Refrigeration unless otherwise defined in this section. 3.1 Acoustic Test Duct. Duct used to convey the sound of the unit configuration under test to the reverberation room during a ducted discharge test. A duct end correction (E1) shall be added to the sound data measured in the reve

18、rberation room to account for the presence of an open-ended duct termination. 3.2 Acoustically Isolated. The specimen under test shall have a sound pressure level at least 10 dB higher than any extraneous sound sources, such as sound generated from the air supply or duct walls, to insure that the te

19、st specimen is the sole contributor to the sound level being measured. 3.3 Air. 3.3.1 Primary Air. Air supplied to an air terminal inlet under positive static gage pressure, normally from an air handling unit. 3.3.2 Secondary Air. Air drawn into an Air Terminal by means of induction and discharged t

20、hrough the air terminal outlet. 3.3.3 Standard Air. Air weighing 1.2 kg/m3which approximates dry air at 21C and at a barometric pressure of 101.3 kPa . ANSI/AHRI STANDARD 881 (SI)-2011 2 3.4 Airflow. Unit volume displacement of standard air per unit time, m3/s . The various types of airflow are defi

21、ned as follows: 3.4.1 Induced Airflow. The flow of secondary air into an Air Terminal resulting from a pressure differential within the terminal.3.4.2 Rated Airflow. The flow of air through an Air Terminal at which test or performance data is generated. 3.4.3 Standard Airflow. Airflow corrected for

22、standard air density. Qs= Qa(a/s) 1 3.5 Air Terminal . A device that modulates the volume of air delivered to or removed from a defined space in response to an external demand (Figure 1). The various types of Air Terminals are: 3.5.1 Bypass Air Terminal. Air Terminal, typically having more than one

23、outlet, that uses a method of volume modulation whereby airflow is varied by distributing that volume required to meet the space requirements with the balance of primary air being diverted away from the space. 3.5.2 Dual Duct Air Terminal. Air Terminal that mixes varying portions of two independent

24、sources of primary air. 3.5.3 Induction Air Terminal. Air Terminal, typically having more than one inlet, that supplies varying proportions of primary and induced air (excludes Fan-Powered Terminals). 3.5.4 Integral Diffuser Air Terminal. Diffuser with the features of an Air Terminal. Air is modulat

25、ed via outlet or inlet dampers. 3.5.5 Modulating Diffuser Air Terminal. A diffuser with an integral Air Terminal. 3.5.6 Fan-Powered Air Terminal. 3.5.6.1 Booster Fan-Powered Air Terminal. Air Terminal similar to a series terminal unit without a primary valve. Unit may have supplemental heat or rehea

26、t. 3.5.6.2 Parallel Flow Fan-Powered Air Terminal. Air Terminal in which the primary air valve is parallel to the fan allowing the primary air to bypass the fan. The fan induces airflow only through the induction port. Unit may have supplemental heat or cooling. 3.5.6.3 Series Flow Fan-Powered Air T

27、erminal. Air Terminal in which the primary air valve is in series with the fan and typically all air flows through the fan. The fan induces airflow from the induction port and the primary air valve. Unit may have supplemental heat or cooling. 3.5.7 Single-Duct Air Terminal. Air Terminal supplied wit

28、h one source of primary air (excludes Fan-Powered Terminals). Unit may have supplemental heat. 3.5.7.1 Reheat Air Terminal. Air Terminal that heats a single source of primary air from a cooling and/or dehumidification source. 3.5.7.2 Exhaust Air Terminal. Air Terminal for regulating exhaust or retur

29、n. 3.6 Damper. A device used to regulate or modulate the flow of air. 3.6.1 Inlet Damper. Controls all air flowing into an Integral Diffuser Air Terminal. 3.6.2 Outlet Damper. Controls only the air being discharged through the diffuser part of an Integral Diffuser Air Terminal. 3.7 Duct End Correcti

30、on. A correction in a frequency band that accounts for the acoustic energy in an acoustic test duct that is prevented from entering the test space by the impedance mismatch created by the termination of the acoustic test duct; a method for computing the Duct End Correction is described in Section 6.

31、 ANSI/AHRI STANDARD 881 (SI)-2011 3 3.8 Equivalent Diameter. Diameter of a circular equivalent of any duct used to determine equal cross-sectional areas. 3.9 Model. An Air Terminal of the same type with similar characteristics available in a progression of sizes. For Fan-Powered Air Terminals, a mod

32、el is defined by a fan size and a progression of various inlet dimensions. For non-Fan-Powered Air Terminals, it is an Air Terminal of various inlet dimensions. 3.10 Octave Band. A band of sound covering a range of frequencies such that the highest is twice the lowest. The octave band center frequen

33、cies of interest are listed in Table 1: Table 1. Octave Band Center Frequencies Octave Band Center Frequency (Hz) 2 125 3 250 4 500 5 1000 6 2000 7 4000 3.11 Piezometric Ring. A duct static pressure averaging apparatus in which a common tube interconnects at least four evenly spaced duct wall taps a

34、nd is connected to a pressure measuring device. 3.12 Power Factor. The ratio of real power to apparent power. Power Factor is a way to describe how much of the current contributes to power in the load. A Power Factor of one indicates that 100% of the current is contributing to power in the load. 3.1

35、3 Pressure. For the purpose of this standard, pressure shall be associated with standard air. 3.13.1 Minimum Operating Pressure. The static pressure drop through an Air Terminal at a given airflow rate with the damper/valve placed in its full open position by its actuator in its normal operating mod

36、e. 3.13.2 Pressure Compensated Control System. Airflow through the Air Terminal is independent of system pressure. 3.13.3 Pressure Dependent Control System. Airflow through the Air Terminal varies in response to system pressure. 3.14 Published Rating. A rating of the assigned values of those perform

37、ance 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 (identification) produced by the same manufacturer. As used herein, the term Published Rating includes the rating of all performan

38、ce characteristics shown on the unit or published in specifications, advertising or other literature controlled by the manufacturer, at stated Rating Conditions. 3.14.1 Application Rating. A rating based on tests performed at application Rating Conditions (other than Standard Rating Conditions). 3.1

39、4.2 Standard Rating. A rating based on tests performed at Standard Rating Conditions. 3.14.3 Certification. A manufacturer participating in an AHRI performance certification program shall use the designation AHRI Performance Certified Ratings. 3.15 Quiet Air Supply. Condition in which the Sound Powe

40、r Level introduced in the frequency band of interest by the air supply alone is at least 10 dB lower than the measured Sound Power Level generated by the air supply and the Air Terminal under test. 3.16 Rating Conditions. Any set of operating conditions under which a single level of performance resu

41、lts, and which causes only that level of performance to occur. ANSI/AHRI STANDARD 881 (SI)-2011 4 3.16.1 Standard Rating Conditions. Rating Conditions used as the basis of comparison for performance characteristics. 3.17 Retrofit Unit. Air Terminal intended for installation into existing air distrib

42、ution systems, and containing little or no sound attenuating materials. Figure 1. Air Terminal and Air Outlet Configuration ANSI/AHRI STANDARD 881 (SI)-2011 5 3.18 “Shall“ or “Should.“ “Shall“ or “should“ shall be interpreted as follows: 3.18.1 Shall. Where “shall“ or “shall not“ is used for a provi

43、sion, that provision is mandatory if compliance with the standard is claimed. 3.18.2 Should. “Should“ is used to indicate provisions which are not mandatory but are desirable as good practice. 3.19 Size. Air Terminal characteristics related to the dimensions of the unit. 3.20 Sound Power. In a speci

44、fied frequency band, the rate at which sound energy is radiated by a noise source, watts. 3.20.1 Discharge Sound Power. Sound Power transmitted from an air terminal outlet. 3.20.2 Radiated Sound Power. Sound Power transmitted from an air terminal casing (plus induction port for Fan-Powered Air Termi

45、nals). 3.21 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 this standard is 1 picowatt (pW). 3.22 Sound Pressure. In a specified frequency

46、 band, a fluctuating pressure superimposed on the static pressure by the presence of sound. 3.23 Sound Pressure Level (Lp). Twenty times the logarithm to the base ten of the ratio of the Sound Pressure radiated by the noise source under test to a reference sound pressure of 20 micropascals, dB. 3.24

47、 Terminal Casing Leakage. Amount of air (at standard conditions) escaping from the terminal at a given inlet pressure with only the outlet(s) blocked and with the damper/valve fully opened. 3.25 Terminal Damper Leakage. Amount of air (at standard conditions) passing through a fully closed damper/val

48、ve at a given inlet pressure. Section 4. Symbols 4.1 Symbols. The symbols used throughout this standard are shown in Table 2. Table 2. Symbols Symbol Quantity Units A Internal cross section of duct m2DeEquivalent diameter = 4 A/ m P Absolute static pressure kPa PaAtmospheric pressure kPa PvVelocity

49、pressure = (V2/2) kPa PsStatic pressure kPa PtTotal pressure = Pv+ PskPa P Differential pressure kPa PtTotal differential pressure kPa QaAirflow at actual test conditions m3/s QsAirflow at standard conditions m3/s V Air Velocity m/s aAir density at actual test conditions kg/m3ANSI/AHRI STANDARD 881 (SI)-2011 6 Section 5. Classifications 5.1 Classifications. Air Terminal units falling within the scope of this standard shall be classified as one of the following nine types: 5.1.1 Single-Duct Air Terminals (Figure 1.a) 5.1.2 Induction Air Terminals (Figure 1.b) 5.1.