1、 4301 NORTH FAIRFAX DRIVE G6c ARLINGTON, VIRGINIA 22203 2001 STANDARD for AIR DIFFUSERS AND AIR DIFFUSER ASSEMBLIES Standard 890 Copyright Air-Conditioning and Refrigeration Institute Provided by IHS under license with ARINot for ResaleNo reproduction or networking permitted without license from IHS
2、-,-,-Price $10.00 (M) $20.00 (NM) Ge3Copyright 2001, by Air-Conditioning and Refrigeration Institute Printed 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 i
3、n accordance with nationally 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-art and accepted industry practices. However, ARI does not certify or guarantee
4、safety of any products, components or systems designed, tested, rated, installed or operated in accordance with these standards or that any tests conducted under its standards will be non-hazardous or free from risk. Note: This standard supersedes ARI Standard 890-94. Copyright Air-Conditioning and
5、Refrigeration Institute Provided by IHS under license with ARINot for ResaleNo reproduction or networking permitted without license from IHS-,-,-TABLE OF CONTENTS SECTION PAGE Section 1. Purpose 1 Section 2. Scope. 1 Section 3. Definitions 1 Section 4. Classifications. 3 Section 5. Test Requirements
6、 3 Section 6. Rating Requirements. 3 Section 7. Minimum Data Requirements for Published Ratings . 4 Section 8. Marking and Nameplate Data . 4 Section 9. Conformance Conditions 4 FIGURES Figure 1. Air Stream Patterns. 1 APPENDICES Appendix A. References - Normative 5 Appendix B. References - Informat
7、ive. 5 Copyright Air-Conditioning and Refrigeration Institute Provided by IHS under license with ARINot for ResaleNo reproduction or networking permitted without license from IHS-,-,-Copyright Air-Conditioning and Refrigeration Institute Provided by IHS under license with ARINot for ResaleNo reprodu
8、ction or networking permitted without license from IHS-,-,-ARI STANDARD 890-2001 1AIR DIFFUSERS AND AIR DIFFUSER ASSEMBLIES Section 1. Purpose 1.1 Purpose. The purpose of this standard is to establish for Air Diffusers and Air Diffuser Assemblies used in air distribution systems: definitions; classi
9、fications; 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.
10、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 Diffusers and Diffuser Assemblies used in air distribution systems which are duct connected to a remote forced air source, as defined in Section 3
11、. 2.2 Exclusions. This standard does not apply to Grilles, Registers, and troffer diffusers. Sound and pressure performance of Diffuser Assemblies providing for automatic volume control shall be rated in accordance with ARI Standard 880. Section 3. Definitions All terms in this document shall follow
12、 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 Air Inlet. A device through which air is removed or returned from a conditioned space. (Grilles, Registers, Diffus
13、ers, and Slots may be used as Air Inlets.) 3.2 Air Outlet. A device or opening through which air is discharged into a conditioned space. It is intended for the purpose of this standard that all accessories, connecting duct adapters, or other mounting airways may be considered part of the outlet devi
14、ce being tested and shall be, in such cases, reported as a unit or assembly. Some specific outlet designations are defined below. 3.2.1 Diffuser. An Air Outlet comprised of deflecting members generally located in the ceiling and designed to distribute air in varying directions and planes. 3.2.2 Diff
15、user Assembly. A terminal assembly consisting of a specifically recommended or fabricated duct, box, or plenum with an integral or attached air outlet or diffuser, such as a slot-plenum, or slot-duct assembly. 3.2.3 Grille. A louvered or perforated face over an opening which is generally located in
16、the sidewall, sill, or floor. 3.2.4 Register. A combination Grille and damper assembly. 3.2.5 Slot Diffuser or Slot. A long narrow air outlet (aspect ratio generally greater than 10:1). 3.3 Air Stream Patterns. These are characterized by the following terms (see Figure 1): Plan View Vertical Cross S
17、ection of the Principal Jet Figure 1. Air Stream Patterns THROWDIFFUSER TERMINAL VELOCITY ENVELOPEANGLE OF DISCHARGESPREAD CENTERLINE OFPRINCIPAL JETSPREADDROPTHROW Copyright Air-Conditioning and Refrigeration Institute Provided by IHS under license with ARINot for ResaleNo reproduction or networkin
18、g permitted without license from IHS-,-,-ARI STANDARD 890-2001 2 3.3.1 Angle of Discharge. The largest included angle between centerlines of principal jets of the primary air stream. 3.3.2 Drop. The vertical distance that the lower edge of a horizontally projected air stream drops between the outlet
19、 and the end of its throw. 3.3.3 Envelope (ISOVEL). The boundary surface of points of equal velocity which describe the air distribution profile (see Figure 1). 3.3.4 Spread. The maximum distance, in ft m, measured parallel to the plane of the outlet between the extremes of the Terminal Velocity Env
20、elope (see Figure 1). 3.3.5 Terminal Velocity (Vt). The highest sustained velocity in the air stream from an outlet, fpm m/s, which is arbitrarily specified and used to determine throw (T). 3.3.6 Throw (T). The distance, ft m, from the center of the outlet to a point in the air stream where the high
21、est sustained velocity of the air stream has been reduced to a specified Terminal Velocity (see Figure 1). 3.4 Area Factor (Ak). An empirical factor of an outlet or inlet, ft2 m2, determined from the discharge or intake velocity (Vk) and the volume flow rate, Q, cfm m3/s. GfaGfbGf9GeaGebGe9=kkkkVsLA
22、VQA 3.5 Aspect Ratio. Ratio of the length/width of a rectangular air outlet. 3.6 Discharge or Intake Velocity (Vk). The average of the velocities of the air stream, fpm m/s, of an outlet or inlet, measured at specified locations relative to the face of the outlet or inlet with a specified instrument
23、. 3.7 Flow Rate. The volume of standard air per unit of time, cfm m3/s, which moves past a given plane. 3.8 Hertz (Hz). A unit of frequency equal to one cycle per second. 3.9 Neck Velocity (Vn). This is measured in fpm m/s and is calculated as follows: GfaGfbGf9GeaGebGe9=nnnnAsLVAQV where Anis the n
24、ominal area, ft2m2, of the duct connection to the Diffuser or Diffuser Assembly. 3.10 Octave Band. A frequency band of sound covering a range of frequencies such that the highest frequency is twice the lowest. The Octave Bands used in this standard are defined in ANSI Standard S1.11. 3.11 Pressure.
25、The force per unit area, in H2O kPa, exerted by a homogeneous liquid or gas. 3.11.1 Static Pressure (SP). The pressure that would be exerted by a moving fluid on a body immersed in it if the body were carried along with the fluid. Practically, it is the normal force per unit area at a small hole in
26、a wall of the duct through which the fluid flows. 3.11.2 Total Pressure (TP). The sum of the Static and Velocity Pressures, in H2O kPa. 3.11.3 Velocity Pressure (VP). The pressure in a moving fluid, in H2O kPa, capable of accelerating the same fluid from rest to the velocity of the fluid with comple
27、te conversion of pressure into kinetic energy. In this standard, Velocity Pressure is a Pressure calculated from duct area and flow rate, at the point of Static Pressure measurement. 3.12 Published Rating. A statement of the assigned values of those performance characteristics, under stated Rating C
28、onditions, 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 performance characteristics shown on the unit or pub
29、lished in specifications, advertising or other literature controlled by the manufacturer, at stated Rating Conditions. 3.12.1 Application Rating. A rating based on tests performed at Application Rating Conditions (other than Standard Rating Conditions). 3.12.2 Standard Rating. A rating based on test
30、s performed at Standard Rating Conditions. 3.13 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. 3.13.1 Standard Rating Conditions. Rating Conditions used as the basis of comparison of perfo
31、rmance characteristics. _Copyright Air-Conditioning and Refrigeration Institute Provided by IHS under license with ARINot for ResaleNo reproduction or networking permitted without license from IHS-,-,-ARI STANDARD 890-2001 33.14 “Shall“ or “Should“. “Shall“ or “should“ shall be interpreted as follow
32、s: 3.14.1 Shall. Where “shall“ or “shall not“ is used for a provision specified, that provision is mandatory if compliance with the standard is claimed. 3.14.2 Should. “Should“ is used to indicate provisions which are not mandatory but which are desirable as good practice. 3.15 Sound Power Level, Lw
33、. This is 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). 3.16 Standard Air. Air weighing 0.075 lb/ft31.2 kg/m3 which approximate
34、s dry air at 70F 21C and at a barometric pressure of 29.92 in Hg 101.3 kPa. Section 4. Classifications 4.1 Classifications. Normally, Diffusers and Diffuser Assemblies falling within the scope of this standard shall be classified as one or more of the following types: a. Plenum Slot Diffusers (with
35、integral factory-mounted plenum) 1. Fixed 2. Adjustable 3. Fire Rated b. Round Diffusers 1. Round Inlet/Round Face c. Perforated Diffusers (perforated panel face) 1. Face-Mounted 2. Neck-Mounted d. Louvered Face Diffusers (horizontal pattern) 1. Fixed Blades Non-Adjustable 2. Fixed Blades Adjustable
36、 Pattern 3. Adjustable Blades e. Square Diffusers 1. Fixed Multiple Cone 2. Fixed Panel or Single Cone 3. Adjustable Multiple Cone 4. Adjustable Panel or Single Cone f. Linear Diffusers (with factory provided plenum) 1. Fixed 2. Adjustable Section 5. Test Requirements 5.1 Test Requirements. Diffuser
37、s and Diffuser Assemblies shall be verified by tests conducted in accordance with the provisions set forth in ASHRAE Standard 70. One exception is that the single stationary microphone provision, as defined in 5.2 of ASHRAE Standard 70, shall be disallowed and the room qualification shall be in acco
38、rdance with ANSI Standard 12.31. For the purposes of this standard, the highest sustained velocity shall be the average velocity determined for a period of not less than 30 seconds. 5.2 The procedures of Section 6 shall be used where calculation procedures are required to develop the Standard Rating
39、. Section 6. Rating Requirements 6.1 Standard Ratings. Standard Ratings shall be established at the Standard Rating Conditions specified in 6.3. 6.2. All Standard Ratings shall be verified by tests in accordance with Section 5. 6.2.1 Values of Standard Ratings. Standard Ratings relating to air flow
40、rates shall be expressed in cfm m3/s of Standard Air and stated as follows: Range, cfm m3/s Rate to Nearest, cfm 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 1 0.5 5 2 10 5 25 10 Isothermal Throw shall be expressed to the nearest 1 ft 0.3 m. Static Pressur
41、e shall be expressed to the nearest 0.01 in H2O 2.5 Pa. Discharge Sound Power Level shall be expressed to the nearest 1.0 decibels. Copyright Air-Conditioning and Refrigeration Institute Provided by IHS under license with ARINot for ResaleNo reproduction or networking permitted without license from
42、IHS-,-,-ARI STANDARD 890-2001 4 6.3 Standard Rating Conditions. The conditions of test for Standard Ratings shall be as follows: Inlet Neck Velocity. .750 fpm 3.8 m/s Exception: Where this velocity is outside the manufacturers recommended velocity, the unit shall be tested at the manufacturers rated
43、 point. Terminal Velocity. 150 fpm 0.76 m/s 6.3.1 Air flow rate shall be determined at the Standard Rating Conditions. 6.3.2 Static Pressure shall be measured at the Standard Rating Conditions. 6.3.3 Discharge Sound Power Level (in dB reference to 10-12watts) shall be determined at the Standard Rati
44、ng Conditions, when installed in accordance with Figure 7 or 8 of ASHRAE Standard 70. 6.3.4 Isothermal Throw shall be measured at the Standard Rating Conditions. 6.4 Application Ratings. Ratings at conditions other than those specified in 6.3 may be published as Application Ratings, and shall be bas
45、ed upon data determined by the method of testing described in Section 5. 6.5 Publication of Ratings. Wherever Application Ratings are published or printed, they shall include or be accompanied by the Standard Rating, clearly designated as such, including a statement of the conditions at which the ra
46、tings apply. 6.6 Tolerances. To comply with this standard, Published Ratings shall be based on data obtained in accordance with the provisions of Sections 5 and 6 of this standard, and shall be such that any production unit, when tested, will meet these ratings within the following tolerances: 6.6.1
47、 The isothermal throw to 150 fpm 0.76 m/s (Terminal Velocity), determined from tests per ASHRAE Standard 70, Section 6.4.4, shall be within 20% or 1 ft 0.3 m whichever is greater, of the published value. 6.6.2 Static Pressure shall not be more than 110% of the Published Rating. 6.6.3 Discharge Sound
48、 Power Level shall not exceed the published values in each Octave Band by more than the rating tolerance shown: Octave Band Center Frequencies, Hz Rating Tolerance, dB 125 250 500 1000 2000 4000 6 4 3 3 3 3 Section 7. Minimum Data Requirements for Published Ratings 7.1 Minimum Data Requirements for Published Ratings. As a minimum, Published Ratings shall include Standard Ratings and Part-Load Ratings (where applicable). All claims to ratings within the scope of this stan
