1、 2011 Standard for Performance Rating of Air Terminals Approved by ANSI on 27 October 2011 ANSI/AHRI Standard 880 (I-P) Price $12.00 (M) $25.00 (NM) Printed in U.S.A. Copyright 2011, by Air-Conditioning, Heating and Refrigeration Institute Registered United States Patent and Trademark Office IMPORTA
2、NT 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, constructed, as
3、sembled, 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. AHRI do
4、es not certify or guarantee that any tests conducted under its standards/guidelines will be non-hazardous or free from risk. AHRI CERTIFICATION PROGRAM PROVISIONS Scope of the Certification Program The certification program includes all Air Terminals as defined in Section 3. Exclusion: This certific
5、ation program does not apply to the rating and testing of retrofit units. Certified Ratings The following certification program ratings are verified by test at the standard rating conditions (Section 7.2): Primary Airflow, cfm Induced or Fan Airflow, cfm Electrical Power Input, watts Minimum Operati
6、ng Pressure, in H2O Radiated Sound Power Level, dB (125 to 4000 Hz octave band) Discharge Sound Power Level, dB (125 to 4000 Hz octave band) USE OF THE SOUND RATINGS Sound power level data generated by use of this standard with air terminals are directly applicable to AHRI Standard 885, a procedure
7、for using published sound ratings in the estimating of sound levels in occupied spaces. Note: For SI ratings, see ANSI/AHRI Standard 881 (SI)-2011. This Standard supersedes AHRI Standard 880-2008 and differs in the following way. Clarification that sound measurements shall be performed in one-third
8、octave band levels and all corrections for background noise and duct end reflection, if applicable, shall be applied to the one-third octave band test data. A Duct End Correction shall be calculated using the actual test duct dimensions, and shall be added to the discharge sound ratings. Foreword Un
9、its tested and rated in accordance with ANSI/AHRI Standard 880 (I-P) are required to be tested in a reverberation room that meets the broadband requirements of AHRI Standard 220. Units certified in accordance with the ANSI/AHRI Standard 880 (I-P) Certification Program are required to be verified by
10、a test in a reverberation room that meets both the broadband and pure tone qualification requirements of AHRI Standard 220. TABLE OF CONTENTS PAGE Section 1. Purpose .1 Section 2. Scope 1 Section 3. Definitions1 Section 4. Symbols5 Section 5. Classifications 6 Section 6. Test Requirements .6 Section
11、 7. Rating Requirements 8 Section 8. Minimum Data Requirements for Published Ratings 11 Section 9. Marking 12 Section 10. Voluntary Conformance 12 TABLES Table 1. Octave Band Center Frequencies .3 Table 2. Symbols5 Table 3. Expression of Airflow Rates 8 Table 4. Minimum Significant Sound Power Level
12、s 8 Table 5. Recommended Inlet Airflow10 Table 6. Discharge/Radiated Sound Power Level Standard Rating Conditions 10 Table 7. Sound Power Level Rating Tolerances 11 FIGURES Figure 1. Air Terminal and Air Outlet Configuration 4 Figure 2. Acoustically Isolated Duct .7 Figure 3. Acoustically Isolated (
13、Lagged) Duct .7 APPENDICES Appendix A. References Normative .13 Appendix B. References Informative .13 ANSI/AHRI STANDARD 880 (I-P)-2011 1 PERFORMANCE RATING OF AIR TERMINALS Section 1. Purpose 1.1 Purpose. The purpose of this standard is to establish for Air Terminals: definitions; classifications;
14、 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 the guidance of the industry, including manufacturers, engineers, installers, contractors and users. 1.1.2 Rev
15、iew 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 in air distribution systems. These devices provide control of air volume with or without temperature control by one or more of the
16、 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 valves (including air induction nozzles and Dampers) 2.1.3 Pressure compensated volume dampers or valves (including air induction nozzl
17、es 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 standard does not apply to registers, diffusers and grilles or to products specifically covered by AHRI Standard 410 or AHRI Standard 440.
18、 Section 3. Definitions All terms in this document follow the standard industry definitions in the current edition of ASHRAE Terminology of Heating, Ventilation, Air Conditioning, and Refrigeration unless otherwise defined in this section. 3.1 Acoustic Test Duct. Duct used to convey the sound of the
19、 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 reverberation room to account for the presence of an open-ended duct termination. 3.2 Acoustically Isolated. The specimen under test sh
20、all 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 test 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
21、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 through the air terminal outlet. 3.3.3 Standard Air. Air weighing 0.075 lb/ft3which approximates dry air at 70F and at a barometric
22、pressure of 29.92 in. Hg. ANSI/AHRI STANDARD 880 (I-P)-2011 2 3.4 Airflow. Unit volume displacement of standard air per unit time, cfm. The various types of airflow are defined as follows: 3.4.1 Induced Airflow. The flow of secondary air into an Air Terminal resulting from a pressure differential wi
23、thin 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 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
24、 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 outlet, that uses a method of volume modulation whereby airflow is varied by distributing that volume required to meet the spac
25、e 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 sources of primary air. 3.5.3 Induction Air Terminal. Air Terminal, typically having more than one inlet, that supplies varying
26、 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 modulated via outlet or inlet dampers. 3.5.5 Modulating Diffuser Air Terminal. A diffuser with an integral Air Terminal. 3.5.6 Fan-Pow
27、ered 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 reheat. 3.5.6.2 Parallel Flow Fan-Powered Air Terminal. Air Terminal in which the primary air valve is parallel to the fan allowing
28、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 Terminal. Air Terminal in which the primary air valve is in series with the fan and typically all air flows through the fan. The
29、 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 with one source of primary air (excludes Fan-Powered Terminals). Unit may have supplemental heat. 3.5.7.1 Reheat Air Terminal. Air
30、 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 return. 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 Inte
31、gral 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 Correction. A correction in a frequency band that accounts for the acoustic energy in an acoustic test duct that is prevented from ente
32、ring 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. ANSI/AHRI STANDARD 880 (I-P)-2011 3 3.8 Equivalent Diameter. Diameter of a circular equivalent of any duct used to determine e
33、qual 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 model is defined by a fan size and a progression of various inlet dimensions. For non-Fan-Powered Air Terminals, it is an Air Ter
34、minal 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 frequencies of interest are listed in Table 1: Table 1. Octave Band Center Frequencies Octave Band Center Frequency (Hz) 2 125 3 250
35、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 and is connected to a pressure measuring device. 3.12 Power Factor. The ratio of real power to apparent power. Power Factor is
36、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. 3.13 Pressure. For the purpose of this standard, pressure shall be associated with standard air. 3.13.1 Minimum Operating Pressur
37、e. 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 mode. 3.13.2 Pressure Compensated Control System. Airflow through the Air Terminal is independent of system pressure. 3.13.3 Pres
38、sure 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 performance characteristics, under stated Rating Conditions, by which a unit may be chosen to fit its application. These values apply
39、 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 performance characteristics shown on the unit or published in specifications, advertising or other literature controlled by the manufac
40、turer, at stated Rating Conditions. 3.14.1 Application Rating. A rating based on tests performed at application Rating Conditions (other than Standard Rating Conditions). 3.14.2 Standard Rating. A rating based on tests performed at Standard Rating Conditions. 3.14.3 Certification. A manufacturer par
41、ticipating in an AHRI performance certification program shall use the designation AHRI Performance Certified Ratings. 3.15 Quiet Air Supply. Condition in which the Sound Power Level introduced in the frequency band of interest by the air supply alone is at least 10 dB lower than the measured Sound P
42、ower 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 results, and which causes only that level of performance to occur. 3.16.1 Standard Rating Conditions. Rating Conditions used as th
43、e basis of comparison for performance characteristics. ANSI/AHRI STANDARD 880 (I-P)-2011 4 3.17 Retrofit Unit. Air Terminal intended for installation into existing air distribution systems, and containing little or no sound attenuating materials. Figure 1. Air Terminal and Air Outlet Configuration A
44、NSI/AHRI STANDARD 880 (I-P)-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 provision, that provision is mandatory if compliance with the standard is claimed. 3.18.2 Should. “Should“ is used to indicate pr
45、ovisions 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 specified frequency band, the rate at which sound energy is radiated by a noise source, watts. 3.20.1 Discharge Sound Power. Soun
46、d 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 Terminals). 3.21 Sound Power Level, Lw. Ten times the logarithm to the base ten of the ratio of the Sound Power radiated by the s
47、ource 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 band, a fluctuating pressure superimposed on the static pressure by the presence of sound. 3.23 Sound Pressure Level (Lp).
48、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 Terminal Casing Leakage. Amount of air (at standard conditions) escaping from the terminal at a given inlet pressure with o
49、nly 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/valve 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 ft2DeEquivalent diameter = 4 A/ Ft P Absolute static pressure in. H2O PaAtmospheric pressure in. Hg PvVelocity pressure = (V/1096)2in. H2O PsStatic pressure in. H2O PtTotal pressure = Pv+ Psin. H2O P Differ
