Addendum to ARI Standard 880-98, Air TerminalsSeptember 2002

The September 2002 Addendum to ARI Standard 880-98, Air Terminals, is comprised of onlythe shaded portions shown, which has been incorporated into the already published 1998 versionof ARI Standard 880 to avoid confusion.

The Addendum addresses a new type of unit, modulating diffuser units, for inclusion in the ARIStandard 880-98. There are no changes to any of the other type of units in this Addendum.

Particular additions (shown shaded in the Standard) are as follows:

1. Add paragraph 3.5.8.2. In paragraph 4.1, add item "i".3. In paragraph 5.1.4.1, add the last sentence.4. In Table 4, in the 3rd row, add the last sentence.5. In Table 5, add 3rd row. Also add Notes 6. and 7 in the last row.6. In Figure 3, add the last figure.7. In Appendix A, add A1.3.

4100 N. FAIRFAX DR., STE. 200 •• ARLINGTON, VIRGINIA 22203

1998STANDARD for

AIRTERMINALS

Standard 880

Price $15.00 (M) $30.00 (NM) ©Copyright 1998, by Air-Conditioning and Refrigeration InstitutePrinted in U.S.A. Registered United States Patent and Trademark Office

IMPORTANT

SAFETY RECOMMENDATIONS

It is strongly recommended that the product be designed, constructed, assembled and installed in accordance withnationally recognized safety requirements, appropriate for products covered by this standard.

ARI, as a manufacturers' trade association, uses its best efforts to develop standards, employing state-of-the-artand accepted industry practices. However, ARI does not certify or guarantee safety of any products, componentsor systems designed, tested, rated, installed or operated in accordance with these standards or that any testconducted under its standards will be non-hazardous or free from risk.

ARI CERTIFICATION PROGRAM PROVISIONS

Scope of the Certification Program

The certification program includes all air terminals as defined in Section 3.

Exclusion: This certification 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 (see Section 6.2):

Primary Air Flow, cfm [m3/s]Induced or Fan Air Flow, cfm [m3/s]Electrical Power Input, watt [W]Minimum Operating Requirement, in. H2O [kPa]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 ARIStandard 885, a procedure for using published sound ratings in the estimating of sound levels in occupied spaces.

Note:

This Standard supersedes ARI Standard 880-94.

TABLE OF CONTENTS

SECTION PAGE

Section 1. Purpose ..................................................................................................................1

Section 2. Scope.....................................................................................................................1

Section 3. Definitions and Symbols ..........................................................................................1

Section 4. Classifications .........................................................................................................4

Section 5. Test Requirements.................................................................................................. 4

Section 6. Rating Requirements................................................................................................5

Section 7. Minimum Data Requirements for Published Ratings ..................................................6

Section 8. Marking and Nameplate Data .................................................................................6

Section 9. Voluntary Conformance .........................................................................................6

TABLES

Table 1. Octave Band Center Frequencies ............................................................................2

Table 2. Nomenclature .........................................................................................................3

Table 3. Minimum Significant Sound Power Levels ...............................................................7

Table 4. Recommended Inlet Air Flow.................................................................................7

Table 5. Discharge/Radiated Sound Power Level Standard Rating Conditions.......................8

FIGURES

Figure 1. Sound Sources for Air Terminals and Air Outlets .....................................................4

Figure 2. Typical Air Terminals, Air Outlets, and Location Relative toCeiling & Floor ......................................................................................................9

Figure 3. Air Terminal and Air Outlet Configuration .............................................................10

Figure 4. Discharge Sound Test for Integral Diffuser Air Terminal - Alternative

Method.................................................................................................................11

Figure 5. Acoustically Isolated Duct.....................................................................................12

Figure 6. Acoustically Isolated (Lagged) Duct ......................................................................12

APPENDICES

Appendix A. References - Normative ........................................................................................13

Appendix B. References - Informative .......................................................................................13

ARI STANDARD 880-1998

1

AIR TERMINALSSection 1. Purpose

1.1 Purpose. The purpose of this standard is to establishfor air terminals : definitions and symbols; classifications;requirements for testing and rating; minimum datarequirements for Published Ratings; marking and nameplatedata; and conformance conditions.

1.1.1 Intent. This standard is intended for theguidance of the industry, including manufacturers,engineers, installers, contractors and users.

1.1.2 Review and Amendment. This standard issubject to review and amendment as technologyadvances.

Section 2. Scope

2.1 Scope. This standard applies to air control anddistribution devices used in commercial air distributionsystems which are ducted air devices and provide control ofair volume and/or air temperature by one or more of thefollowing means:

a. Fixed or adjustable directional vanes.b. Pressure dependent volume dampers or shutoff

valves (including air induction nozzles anddampers).

c. Pressure compensated volume dampers orshutoff valves (including air induction nozzlesand dampers).

d. Heat exchange.e. On/off fan control.f. Variable speed fan control.

These devices may or may not have a fan to deliver air into aspace.

2.2 Exclusions. This standard does not apply to registers,diffusers and grilles or to products specifically covered by:

a. The Air Heating and Cooling Coils Sub-Sectionof the Air Conditioning Heat Transfer ProductsSection of ARI. ARI Standard 410.

b. The Room Fan-Coil and Air-Induction UnitsSub-Section of the Air Conditioning HeatTransfer Products Section of ARI. ARIStandard 440.

Section 3. Definitions and Symbols

3.1 Definitions. All terms in this document will follow thestandard industry definitions in the current edition of ASHRAE Terminology of Heating, Ventilation, AirConditioning, and Refrigeration unless otherwise defined inthis section.

3.2 Acoustically Isolated. The specimen under test shallhave a sound pressure level at least 10 dB higher than anyextraneous sound sources, such as sound generated from theair supply or duct walls, to insure that the test specimen is thesole contributor to the sound level being measured (seeFigure 1).

3.3 Air.

3.3.1 Primary Air. Air supplied to an air terminalinlet under positive static gage pressure, normally froman air handling unit.

3.3.2 Secondary Air. Air drawn into an air terminalby means of induction and discharged through the airterminal outlet.

3.3.3 Standard Air. As defined in ASHRAETerminology of Heating, Ventilation, AirConditioning and Refrigeration, dry air at 70EF[20EC] and 14.696 psia [101.325 kPa]. Under theseconditions, dry air has a mass density of 0.075 lb/ft3

[1.204 kg/m3].

3.4 Airflow. Unit volume displacement of standard air perunit time. Normally measured in cubic feet per minute (cfm) orcubic meters per second (m3/s). The various types of airfloware defined as follows:

3.4.1 Design Airflow. The flow of conditioned airthrough an air terminal required to meet a givenheating or cooling design load.

3.4.2 Rated Airflow. The flow of air through an airterminal at which test or performance data is generated.

3.4.3 Standard Airflow. Airflow corrected forstandard air density. Qs = Qa (ña/ñs).

3.4.4 Induced Airflow. The flow of secondary airinto an air terminal resulting from a pressure differentialcreated by the velocity of the flow of primary airthrough the terminal.

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2

3.5 Air Terminal (Terminal). A device that modulates thevolume of air delivered to a conditioned space in response toa given load (see Figures 2 and 3). The various types of airterminals are:

3.5.1 Bypass Terminal. Air terminal that divertsexcess primary air to the return.

3.5.2 Integral Diffuser Terminal. Diffuser with thefeatures of an air terminal.

3.5.3 Dual Duct Terminal. Air terminal with twosupply inlets that is used primarily for mixing cold andwarm air streams at varying proportions.

3.5.4 Induction Terminal. Air terminal thatsupplies varying proportions of primary and inducedair.

3.5.5 Parallel Flow Fan-Powered Terminal. Airterminal in which primary airflow is modulated inresponse to the cooling demand and in which theintegral fan is operated to deliver induced air.

3.5.6 Series Flow Fan-Powered Terminal. Airterminal in which the primary airflow is modulated andmixed with induced air by a continuously operatedintegral fan to provide a relatively constant volumedischarge.

3.5.7 Single-Duct Terminal. Air terminal suppliedwith one source of primary air.

3.5.8 Modulating Diffuser Terminal. A diffuserwith an integral air terminal.

3.6 Damper. A device used to regulate or modulate theflow of air.

3.6.1 Inlet Damper. Controls all air flowing into anintegral diffuser terminal.

3.6.2 Outlet Damper. Controls only the air beingdischarged through the diffuser part of an integraldiffuser terminal.

3.7 Equivalent Diameter. Diameter of a circular equivalentof any duct for equal cross-sectional areas.

3.8 Model. An air terminal of the same type with similarcharacteristics available in a progression of sizes. For fan-powered air terminals, a model is defined by a progression ofvarious inlet dimensions and fan volume capacities. For non-fan-powered air terminals, it is an air terminal of various inletdimensions.

3.9 Octave Band. Frequency band with an upper bandlimit that is twice the frequency of the lower band limit. Thecenter frequency of an Octave Band is the geometric mean ofits upper and lower band limits. The octave band centerfrequencies of interest are listed in Table 1:

Table 1. Octave Band Center Frequencies

Octave Band Center Frequency (Hz)

1 63

2 125

3 250

4 500

5 1000

6 2000

7 4000

8 8000

3.10 Piezometric Ring. A duct static pressure averagingarrangement in which a common tube interconnects at leastfour evenly-spaced duct wall taps and is connected to apressure measuring device.

3.11 Pressure. For the purpose of this standard, pressureshall be associated with standard air.

3.11.1 Minimum Operating Pressure. The staticpressure drop through an air terminal at a givenairflow, with the damper/valve placed in its full openposition.

3.11.2 Pressure Compensated Control System. Airflow through the air terminal is independent ofsystem pressure.

3.11.3 Pressure Dependent Control System. Airflowthrough the air terminal varies in response with systempressure.

3.12 Published Ratings. A statement of the assignedvalues of those performance characteristics, under statedrating conditions, by which a unit may be chosen to fit itsapplication. These values apply to all units of like nominalsize and type (identification) produced by the samemanufacturer. As used herein, the term Published Rating"includes the rating of all performance characteristics shownon the unit or published in specifications, advertising or otherliterature controlled by the manufacturer, at stated ratingconditions.

3.12.1 Standard Rating. A rating based on testsperformed at Standard Rating Conditions.

ARI STANDARD 880-1998

3

3.12.2 Application Rating. A rating based on testsperformed at application rating conditions (other thanStandard Rating Conditions).

3.13 Quiet Air Supply. Condition in which the sound powerlevel introduced in the frequency band of interest by the airsupply alone is at least 10 dB lower than the measured soundpower level generated by the air supply and the air terminalunder test.

3.14 Rating Conditions. Any set of operating conditionsunder which a single level of performance results, and whichcauses only that level of performance to occur.

3.14.1 Standard Rating Conditions. Ratingconditions used as the basis of comparison forperformance characteristics.

3.15 Retrofit Unit. Air terminal intended for installation intoexisting air distribution systems, and containing little or nosound attenuating materials.

3.16 "Shall," "Should," "Recommended" or "It IsRecommended." "Shall," "should," "recommended" or "it isrecommended" shall be interpreted as follows:

3.16.1 Shall. Where "shall" or "shall not" is usedfor a provision, that provision is mandatory ifcompliance with the standard is claimed.

3.16.2 Should, Recommended or It Is Recommended. "Should," "recommended" or "it is recommended" isused to indicate provisions which are not mandatorybut are desirable as good practice.

3.17 Size. Air terminal characteristics related to thedimensions of the unit.

3.18 Sound Power. In a specified frequency band, the rateat which sound energy is radiated by a noise source,measured in watts.

3.19 Sound Power Level. In a specified frequency band,ten times the common logarithm of the ratio of the soundpower radiated by the noise source under test to the standardreference sound power of 10-12 watt.

3.20 Sound Power-Radiated. Sound power transmittedfrom an air terminal casing (plus induction port for fan-powered air terminals).

3.21 Sound Power - Discharge. Sound power transmittedfrom an air terminal outlet.

3.22 Sound Pressure. In a specified frequency band, afluctuating pressure superimposed on the static pressure bythe presence of sound.

3.23 Sound Pressure Level. In a specified frequency band,20 times the common logarithm of the ratio of the soundpressure radiated by the noise source under test to thestandard reference pressure of 20 micropascals.

3.24 Symbols and Abbreviations. The nomenclature usedthroughout this standard is shown in Table 2.

Tab le 2 . Nomenc la tureTab le 2 . Nomenc la ture

Symbol Quantity I - P Units SI Units

ADe

PPa

Pv

Ps

Pt

ÄPÄPt

Qa

Qs

Vña

ñs

Lw

Lp

Internal cross section of duct

Equivalent diameter = πA/* 4Absolute static pressureAtmospheric pressureVelocity pressure = ñ* (V/1096)2 [ñ*v2/2]Static pressureTotal pressure = Pv + Ps

Differential pressureTotal differential pressureAirflow at actual test conditionsAirflow at standard conditionsAir VelocityAir density at actual test conditionsAir density at standard conditionsSound Power LevelSound Pressure Level

ft2

ftin. H2Oin. Hgin. H2Oin. H2Oin. H2Oin. H2Oin. H2O

ft3/min (cfm)ft3/min (cfm)ft/min (fpm)

lbm/ft3

lbm/ft3

dBdB

m2

mPakPakPakPakPakPakPam3/sm3/sm/s

kg/m3

kg/m3

dBdB

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4

F igure 1 . Sound Sources fo r A i r Termina ls and A i r Out le tsF igure 1 . Sound Sources fo r A i r Termina ls and A i r Out le ts

Section 4. Classifications (Types)

4.1 Classifications (Types) . Terminal units falling withinthe scope of this standard shall be classified as oneof the following eight types:

a. Single-Duct Central Air Terminalsb. Dual Duct Central Air Terminalsc. Induction Central Air Terminalsd. Bypass Central Air Terminalse. Series Flow, Fan Powered Central Air Terminalsf. Parallel Flow, Fan-Powered Central Air Terminalsg. Inlet Damper, Integral Diffuser Terminalsh. Outlet Damper, Integral Diffuser Terminalsi. Modulating Diffuser Terminals

Section 5. Test Requirements

5.1 Test Requirements. Air terminals shall be tested inaccordance with ASHRAE Standard 130, except as notedbelow.

5.1.1 Calibration . Instruments shall be calibratedat least once per year by comparison with a certifiedstandard in the range of use or shall itself have beencertified as to accuracy.

5.1.2 Supply Air Static Pressure Measurement. The static pressure of the air entering the test unitshall be measured by means of a Piezometer ring perSection 4.6.2 of ASHRAE Standard 130.

5.1.3 Discharge Air Static PressureMeasurement. The static pressure of the air shall bemeasured at 2.5 duct diameters downstream of theterminal outlet. A piezometer ring shall be used ifstatic pressure traverse measurements are not uniformwithin 10%.5.1.4 Sound Measurement Installation.

ARI STANDARD 880-1998

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5.1.4.1 Discharge Sound Power LevelDetermination. To determine dischargesound power level, the air terminal shall beinstalled in accordance with Figures 9.1through 9.4 of ASHRAE Standard 130. Alternatively, for integral diffuser airterminals, the discharge sound power levelmay be determined in accordance withFigure 4. For Modulating DiffuserTerminals, the discharge sound power levelshall be determined in accordance withFigures 7 and 8 of ASHRAE Standard 70.

5.1.4.2 Radiated Sound Power LevelDetermination. The air terminal shall beinstalled in accordance with Figures 10.1through 10.3 of ASHRAE Standard 130 todetermine radiated sound power level.

5.1.4.3 Mounting of EquipmentRequiring Support. To achieve isolation, atrapeze type mounting with rubber isolatingpads shall be used for all compatibleterminals.

5.1.4.4 Acoustically Isolated Duct.Recommendations for acoustically isolatedducts, or equivalents, used as inlet andoutlet ducts in radiated sound tests areshown in Figures 5 and 6.

5.1.4.5 Dual Duct Air Terminal TestConfiguration. Dual duct terminals shall betested with one valve controlling air flowand one valve fully closed.

5.1.5 Radiated Sound Power Tests - SeriesFlow Fan Terminals. The total air flowdischarging the test unit shall be measured usingan acoustically isolated flow measuring deviceinstalled as shown in Figure 6 of ASHRAEStandard 130 (3.5 De distance to discharge flowmeasuring device is a minimum value.)

5.1.6 Induced Airflow. Induced airflow iscalculated by subtracting the primary airflow from thedischarge (total) airflow. Primary airflow is measuredin accordance with Section 4.4 and discharge (total)airflow is measured in accordance with Section 5.1 ofASHRAE Standard 130.

Section 6. Rating Requirements

6.1 Standard Ratings. Standard Ratings shall beestablished at the Standard Rating Conditions specified in6.2. All Standard Ratings shall be verified by tests inaccordance with Section 5.

6.1.1 Values of Standard Ratings. StandardRatings relating to air flow rates shall be expressedonly in cfm [m3/s] of Standard Air and stated asfollows:

Rangecfm [m3/s]

0 to 49 [0 to 24]50 to 199 [25 to 99]

200 to 999 [100 to 499]1000 and over [500 and over]

Rated toNearest

1 cfm [0.5 m3/s]5 cfm [2 m3/s]10 cfm [5 m3/s]25 cfm [10 m3/s]

Static pressure shall be expressed to the nearest 0.01in. H2O [0.0025 kPa].

Discharge and radiated sound power level shall beexpressed to the nearest 1 dB. Levels below valuesshown in Table 3 shall be listed as being belowsignificance. The Sound Power Level shall bedetermined for the octave band center frequenciesfrom 125 to 4000 Hertz.

Watts shall be expressed to the nearest 1 watt.

6.2 Standard Rating Conditions.

6.2.1 Air Flow Rate and Minimum OperatingPressure.

6.2.1.1 Primary Damper. The standardrated air flow and minimum operatingpressure shall be established and publishedin accordance with Table 4.

6.2.1.2 Integral Fan . Fan air flow ratingshall be established and published at 0.25 in.H2O [0.062 kPa] discharge static pressure orminimum recommended pressure (whicheveris greater) with any fan volume dampers atwide open position, and primary air valveclosed.

6.2.1.3 Induction Terminal. Theinduced airflow shall be rated and publishedusing 0.25 in. H2O [0.062 kPa] discharge(downstream) static pressure with theprimary air damper set to achieve 25% of the

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6

standard rated airflow and 1.5 in. H2O [0.37kPa] inlet static pressure. The inductiondamper(s) shall be set in the full openposition.

6.2.2 Sound Power Rating. The sound powerlevel, dB, for both discharge and radiated shall beestablished and published at the Standard RatingConditions (see Table 5).

6.3 Application Ratings. Data at conditions other thanthose specified in 6.2 may be published as applicationratings, and shall be determined in accordance with themethod of testing described in Section 5.

6.4 Appurtenance Ratings. The terminal data referred toin 6.2 represent the performance of the base terminal withoutappurtenances. Thus, as appurtenances such as reheat coils,filters, multiple outlet connectors, etc. are added to theterminal, their effects must be taken into account in order toestablish the overall performance of the combined terminal.

6.5 Publication of Ratings. Wherever application ratingsare published or printed, they shall include or beaccompanied by the Standard Rating, clearly designated assuch, including a statement of the conditions at which theratings apply.

6.6 Tolerances. To comply with this standard, publishedratings shall be based on data obtained in accordance withthe provisions of Sections 5 and 6 of this standard, and shallbe such that any production terminal, when tested, will meetthese ratings within the following tolerances:

6.6.1 Air flow shall be greater than or equal to95% of the rating at the published minimum operatingpressure requirement.

6.6.2 For fan powered terminals, air flow shall begreater than or equal to 95% of the rating at thepublished minimum operating pressure and theelectrical power input shall not be more than 110% ofthe rated value. For induction terminals, the inducedairflow shall be greater than or equal to 95% of therating.

6.6.3 Sound Power levels shall not exceed thepublished values in each octave band by more thanthe rating tolerance shown following:

Octave Band CenterFrequencies, Hz

125250500100020004000

Rating TolerancedB643333

Section 7. Minimum Data Requirementsfor Published Ratings

7.1 Minimum Data Requirements for Published Ratings.Published ratings shall include Standard Ratings and mayalso include application ratings. The following informationshall be published for all Standard Ratings.

a. A listing of all applicable rating conditionsspecified.

b. Primary air flow rate, cfm [m3/s]c. Induced or fan air flow rate, cfm [m3/s]d. Minimum operating pressure, in. H2O [kPa]e. Octave band sound power level, dB (125 to

4000 Hz)f. Electrical power input at fan rating point, W

(fan-powered terminals only)

Section 8. Marking and Nameplate Data

8.1 Marking and Nameplate Data. Recommendednameplate voltages for 60 Hertz systems shall include one ormore of the equipment nameplate voltage ratings shown inTable 1 of ARI Standard 110. Recommended nameplatevoltages for 50 Hertz systems shall include one or more ofthe utilization voltages shown in Table 1 of IEC StandardPublication 38.

8.2 Model Identification. The label on each air terminalunit shall include sufficient model and size identification tocorrelate with published data, literature and any otheradvertising issued by the manufacturer.

Section 9. Voluntary Conformance

9.1 Conformance. While conformance with this standardis voluntary, conformance shall not be claimed or implied forproducts or equipment within its Purpose (Section 1) andScope (Section 2) unless such claims meet all of therequirements of the standard.

ARI STANDARD 880-1998

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Table 3. Minimum Significant Sound Power Levels

Octave Band CenterFrequency, Hz

125 250 500 1000 2000 4000

Sound Power Level, dB 36 29 26 22 19 17

Table 4. Recommended Inlet Air Flow

Inlet Duct Diameter, Inch [mm] Airflow, cfm [m3/s]

4 [102] 5 [127] 6 [152] 7 [178] 8 [203] 9 [229]10 [254]12 [305]14 [356]16 [406]18 [457]20 [508]22 [559]24 [610]

150 [0.071]250 [0.118]400 [0.189]550 [0.260]700 [0.330]900 [0.425]1100 [0.519]1600 [0.775]2100 [0.991]2800 [1.32]3500 [1.65]4400 [2.08]5300 [2.50]6300 [2.97]

Any other size unit or configuration shall be rated at the air flow rate calculated from multiplying the nominal inlet area, ft2

[m2] by 2000 fpm [10.2 m/s] air velocity.

For Series Flow Fan-Powered Terminals, the rated air flow cfm [m3/s] for the primary air valve shall be the lower of the fanrating flow or the rated air flow according to the above table.

Integral Diffuser Terminals and Bypass Terminals shall be rated at the manufacturer's recommended air flow.

Modulating Diffuser Terminals shall be rated at 750 fpm [3.8 m/s] and 400 fpm [2.0 m/s] neck velocity.

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Table 5. Discharge/Radiated Sound Power Level Standard Rating Conditions

Type of Sound Primary AirTerminal Type TestPoint

Radiated Discharge Discharge (Downstream)Static Pressure in. H2O

[kPa] 1

Fan 2

Air Flow Percentof Rated Air Flow

Differential StaticPressure in. H2O

[kPa]

Single Duct, DualDuct, IntegralDiffuser Terminals

12

Yes�

�Yes

NANA

NANA

100100

1.5 [0.37]1.5 [0.37]

ModulatingDiffuserTerminals

12

--

YesYes

NANA

NANA

1006

Throttled7MinimumSee Note 7

Bypass Terminals 12

Yes-

-Yes

NANA

NANA

100100

MinimumMinimum

Parallel Flow Fan Powered Terminals & Induction Units

Fan Only 12

Yes�

�Yes

0.25 [0.06]0.25 [0.06]

OnOn

OffOff

��

Primary Air Only 34

Yes�

�Yes

0.25 [0.06]0.25 [0.06]

Off 5

Off 5100100

1.5 [0.37]1.5 [0.37]

Series Flow Fan Powered Terminals

Fan Only 1 � Yes 0.25 [0.06] On Off _

Fan and PrimaryAir

23

YesYes

��

0.25 [0.06]0.25 [0.06]

OnOn

Off100 3

-1.5 [0.37] 4

NOTES:1. All fan tests for radiated and discharge sound in fan powered terminals shall be run at 0.25 in. H2O [0.06 kPa] discharge

static pressure or at minimum recommended discharge static pressure, whichever is higher.2. Fan to be adjusted to its rated air flow, using manufacturer's recommended procedure.3. Primary air flow set for 100% recommended inlet air flow in accordance with Table 4 or fan maximum rated air flow,

whichever is lower.4. Inlet static pressure, referenced to atmosphere for series flow fan powered terminal only.5. Induction units shall be tested with induction dampers set fully closed.

6. At full open damper position and 750 fpm [3.8 m/s] neck velocity.

7. At the throttled damper position which produces the manufacturer’s maximum recommended inlet static pressure at 400fpm [2.0 m/s] neck velocity.

ARI STANDARD 880-1998

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F igure 2 . Typ ica l A i r Termina ls , A i r Out le ts , and Locat ion Re la t ive toF igure 2 . Typ ica l A i r Termina ls , A i r Out le ts , and Locat ion Re la t ive toCe i l ing & F loorCe i l ing & F loor

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Figure 3. Air Terminal and Air Outlet Configuration

ARI STANDARD 880-1998

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Figure 4. Discharge Sound Test for Integral Diffuser Air Terminal - Alternative Method

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ARI STANDARD 880-1998

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APPENDIX A. REFERENCES - NORMATIVEA1 Listed here are all standards, handbooks, and otherpublications essential to the formation and implementationof the standard. All references in this appendix areconsidered as part of this standard.

A1.1 ANSI Standard S12.31-1990, Precision Methodsfor the Determination of Sound Power Levels of Broad-Band Noise Sources in Reverberation Rooms, 1990,American National Standards Institute, Inc., 11 West42nd Street, New York, NY 10036, U.S.A.

A1.2 ANSI Standard S12.32-1990, Precision Methodsfor the Determination of Sound Power Levels ofDiscrete-Frequency and Narrow-Band Noise Sourcesin Reverberation Rooms, 1990 American NationalStandards Institute, Inc., 11 West 42nd Street, NewYork, NY 10036, U.S.A.

A1.3 ANSI/ASHRAE Standard 70-1991, Method ofTesting for Rating Performance of Air Outlets andInlets, 1991, American Society of Heating, Refrigeratingand Air-Conditioning Engineers, Inc., 1791 Tullie Circle,N.E., Atlanta, GA 30329, U.S.A.

A1.4 ARI Standard 110-97, Air-Conditioning andRefrigerating Equipment Nameplate Voltages, 1997Air-Conditioning and Refrigeration Institute, 4301 NorthFairfax Drive, Suite 425, Arlington, VA 22203, U.S.A.

A1.5 ASHRAE 130-1996, Methods of Testing forRating Ducted Air Terminal Units, 1996, AmericanSociety of Heating, Refrigerating, and Air-ConditioningEngineers, Inc., 1791 Tullie Circle N.E., Atlanta, GA30329, U.S.A.

A1.6 ASHRAE Terminology of Heating, Ventilation,Air Conditioning, & Refrigeration, 1991, SecondEdition, American Society of Heating, Refrigerating, andAir-Conditioning Engineers, Inc., 1791 Tullie Circle N.E.,Atlanta, GA 30329, U.S.A.

A1.7 IEC Standard Publication 38, IEC StandardVoltages, 1983, nternational ElectrotechnicalCommission, 3, rue de Varembe, P.O. Box 131, 1211Geneva 20, Switzerland.

APPENDIX B. REFERENCES - INFORMATIVENone.