Publication 99-86 Standards Handbook Purpose of AMCA Standards AMCA Standards are adopted in the public interest. They are intended to eliminate misunderstandings between the manufacturer and the purchaser and to assist in selecting, specifying, and obtaining the proper product for the particular need. Existence of an AMCA Standard does not in any respect preclude any member or non-member from manufacturing or selling products not conforming to the Standard. Approval of Standards Proposed Standards are reviewed by the appropriate Standards Committees and by the Board of Directors before submittal to the membership for approval. An affirmative vote of two-thirds of the members affected is required for adoption or revision. Review of Standards AMCA Standards are regularly reviewed, but may also be reviewed at any time at the request of the members hip or by direction of the Board of Directors. AMCA STANDARDS HANDBOOK CONTENTS GENERAL 99-0066-83 99-0098-76 99-0100-76 99-0401-86 Product Definitions Basic Series of Preferred Numbers Metric Units and Conversion Factors Classifications for Spark Resistant Construction CENTRAL STATION UNITS 99-1401-66 Operating Limits for Central Station Units CENTRIFUGAL FANS 99-2001-82 99-2002-82 99-2003-82 99-2401-82 99-2402-82 99-2404-78 99-2405-83 99-2406-83 99-2407-66 99-2408-69 99-2410-82 99-2411-82 Metric Impeller Diameters & Outlet Areas for Centrifugal Fans Metric Dimensions for Industrial Centrifugal Fans Metric Impeller Diameters & Outlet Areas for Tubular Centrifugal Fans Impeller Diameters & Outlet Areas for Centrifugal Fans & Metric Equivalents Dimensions for Industrial Centrifugal Fans & Metric Equivalents Drive Arrangements for Centrifugal Fans Inlet Box Positions for Centrifugal Fans Designation for Rotation & Discharge of Centrifugal Fans Motor Positions for Belt or Chain Drive Centrifugal Fans Operating Limits for Centrifugal Fans Drive Arrangements for Tubular Centrifugal Fans Impeller Diameters & Outlet Areas for Tubular Centrifugal Fans & Metric Equivalents AXIAL FANS 99-3001-76 99-3002-76 99-3003-76 99-3404-83 Metric Dimensions for Axial Fans Metric Dimensions for Axial Fan Transitions Metric Orifice Dimensions for Propeller Fans Drive Arrangement for Axial Fans With or Without Evase and Inlet Box © 1986 by Air Movement and Control Association, Inc. AIR MOVEMENT DIVISION FAN FAN —A power-driven machine used to move a volume of gas. IMPELLER (WHEEL, ROTOR, PROPELLER) —The rotating portion of the fan designed to increase the energy level of the gas stream. HOUSING (CASING, VOLUTE)— A stationary impeller enclosure designed to direct the flow of the gas stream through the fan. The housing may also affect the energy transformations of the gas stream. AXIAL FANS AXIAL FAN —A fan in which the airflow through the impeller is predominantly parallel to the axis of rotation. The impeller is contained in a cylindrical housing. TUBEAXIAL FAN —An axial fan without guide vanes. VANEAXIAL FAN — An axial fan with either inlet or discharge guide vanes or both. • Fixed Pitch—impeller blades are permanently secured at a given angle on the impeller hub. • Adjustable Pitch — Impeller blade angle can be mechanically altered when the impeller is at a standstill. • Variable Pitch— Impeller blade angle can be mechanically or hydraulically altered while the impeller is rotating, PROPELLER FAN —An axial flow fan with a propeller-type wheel mounted within an orifice plate or ring. CENTRIFUGAL FANS CENTRIFUGAL FAN —A fan in which the airflow through the impeller is primarily axial upon entering the impeller and is changed by the impeller blades to an essentially radial flow at the impeller’s discharge. The impeller is moat generally contained In a volute-type housing. Several types of centrifugal impellers in common use are backward inclined, airfoil, radial, radial tip and forward curved impellers. TUBULAR CENTRIFUGAL FAN —A fan with a centrifugal impeller within a cylindrical housing discharging the gas in an axial direction. CLASS STANDARDS— Defines the capability of a fan to operate safely at every point of rating on a minimum performance limit for that class. See AMCA Standard 99-2408. MIXED FLOW FANS MIXED FLOW FAN —A fan in which the air flow is primarily parallel to the axis of rotation and is changed by the blade shape to induce a radial flow component at the discharge which is generally small. The impeller may be contained in either a cylindrical or volute casing. AMCA STANDARD 99-0066-83 PAGE 1 OF 3 Adopted 2-22-83 PRODUCT DEFINITIONS Reviewed Supersedes 1-66 FAN APPURTENANCES FAN APPURTENANCES—Accessories added to a fan for purposes of control, isolation, safety, static pressure regain, wear, etc. Common fan appurtenances include inlet boxes, inlet box dampers, variable inlet vanes, outlet dampers, vibration isolation bases, inlet screens, belt guards, evases or diffusers, sound attenuators, wear protection, turning gears, etc. SPECIFIC FAN UNITS CENTRAL STATION AIR- HANDLING UNIT* —A factory-made encased assembly consisting of a fan or fans and other necessary equipment to perform one or more of the functions of circulating, cleaning, heating, cooling, humidifying, dehumidifying, and mixing of air; but which does not include a source of heating or cooling. This device is capable of use with ductwork of total static resistance of at least 1/4 inch water (62 Pa). • Draw-Through Central-Station Air-Handling Unit —A unit containing heat exchanger(s) upstream of the fan. • Blow-Through Central-Station Air-Handling Unit —A unit containing heat exchanger(a) downstream of the fan. • Ventilating Unit —A unit which includes means for providing ventilating, and which may also include means for cleaning, humidifying, and/or mixing air. • Heating Unit —A unit which includes means for heating, and which may also include means for cleaning, humidifying, mixing, and/or bypassing air and/or for providing ventilation. • Cooling Unit —A unit which includes means for cooling, and which may also include means for humidifying, dehumidifying, cleaning, mixing, and/or bypassing air, and/or for providing ventilation. • Cooling-Heating Unit —A unit which Includes means for cooling and heating, and which may also include means for dehumidifying, humidifying, cleaning, mixing, and/or bypassing air, and/or providing ventilation. STEAM OR HOT WATER UNIT HEATERS—A factory-assembled unit designed to heat and circulate air. Essential components are a heat transfer element using steam or hot water as the heating medium and a housing with fan(a) and drive motor(s). Unit heaters may be provided with components for filtering, ventilating and/or diffusing the discharge air. POWER ROOF OR WALL VENTILATORS—A fan consisting of a centrifugal or axial type impeller with integral driver in a weather-resistant housing with base designed to fit, usually by means of a curb, over a wall or roof opening. Specifically excluded are fans with integral air tempering means. UTILITY SET—A centrifugal fan designed as a packaged unit, ready to run, either belt-driven or directly connected to an electric motor. CENTRIFUGAL CEILING OR WALL EXHAUSTER —A factory-assembled fan consisting of one or several centrifugal wheels directly connected to a motor and enclosed in a housing. An inlet grille and backdraft damper are usually included. Installation can be in a ceiling or wall. AIR CURTAIN UNIT—A mechanical air moving device designed to produce an air curtain. • Air Curtain —A controlled stream of air moving across the height and width of an opening with sufficient velocity and volume to reduce the infiltration or transfer of air from one side of the opening to the other and/or to inhibit insects, dust or debris from passing through. MAKE-UP AIR UNITS—Factory-assembled fan-heater units used to supply tempered fresh air to make up for exhaust In factories, garages, auditoriums, etc. Centrifugal or axial fans are utilized with direct gas-fired, steam, electric, or water heater sections. *ref: ARI Standard 430-78 AMCA STANDARD 99-0066-83 PAGE 2 OF 3 Adopted 2-22-83 Reviewed PRODUCT DEFINITIONS I Supersedes 1-66 AIR CONTROL DIVISION LOUVER—A device comprising multiple blades which, when mounted in an opening, permits the flow of air but inhibits the entrance of other elements. • Fixed Louver—A louver in which the blades do not move. • Adjustable Louver—A louver in which the blades may be operated either manually or by mechanical means. PENTHOUSE—A roofed structure incorporating louvers or louver blades in all or part of the walls and usually designed to be on the roof of a building. VOLUME CONTROL DAMPER — A device which, when mounted in a duct or opening, is used to vary the volume of air flowing through the duct or opening. It may be operated manually or mechanically and may have one or more blades. • Parallel Blade Damper—A damper in which the blades rotate in the same direction. • Opposed Blade Damper—A damper in which adjacent blades rotate in the opposite direction. BACKDRAFT DAMPER (SHUTTER)— A device which, when mounted in a duct or opening, permits the flow of air in one direction only. It is normally opened by the energy of the air stream but may be opened and/or closed by mechanical means. A counterbalanced backdraft damper has weights and/or springs added to the blade or blades to facilitate or impede the opening or closing action. GUILLOTINE DAMPER—An isolation damper having blade(s) which is (are) withdrawn from the duct area when the damper is fully open. GUILLOTINE DAMPER-DOUBLE BLADE—A guillotine damper having two parallel blades which can be pressurized by a seal air system to prevent leakage of upstream duct fluids when the blades are closed. FIRE DAMPER— A fire damper is a device arranged to interrupt airflow automatically through part of an air system so as to restrict the passage of flame, and is installed in a fire-rated wall or floor to close automatically in the event of a fire in order to maintain the integrity of the fire-rated separation. CEILING DAMPER—A ceiling damper is a device to protect air openings in fire-rated ceiling assemblies which operates to interrupt airflow automatically in the event of a fire so as to restrict the passage of flame and heat. AMCA STANDARD 99-0066-83 PAGE 3 OF 3 PRODUCT DEFINITIONS Adopted 2-22-83 Reviewed Theoretical values Mantissa of logarithms (6) Calculated values (7) Percentage differences between basic series end calculated values (%) (8) 000 025 050 075 100 125 150 175 200 225 250 275 300 325 350 375 400 425 450 475 500 525 550 575 600 625 650 675 700 725 750 775 800 825 850 875 900 925 950 975 000 1.0000 1.0593 1.1220 1.1685 1.2569 1.3335 1.4125 1.4962 1.5649 1.6788 1.7763 1.6636 1.9953 2.1135 2.2367 2.3714 2.5119 2.6607 2.6184 2.9654 3.1623 3.3497 3.5461 3.7584 3.9811 4.2170 4.4666 4.7315 5.0119 5.3088 5.6234 5.9586 6.3096 6.6834 7.0795 7.4989 7.9433 8.4140 8.9125 9.4405 10.0000 0 + 0.07 - 0.18 - 0.71 - 0.71 - 1.01 - 0.88 + 0.25 + 0.95 + 1.26 + 1.22 + 0.87 + 0.24 + 0.31 + 0.06 - 0.48 - 0.47 - 0.40 - 0.65 + 0.49 - 0.39 + 0.01 + 0.05 - 0.22 + 0.47 + 0.78 + 0.74 + 0.39 - 0.24 - 0.17 - 0.42 + 0.73 - 0.15 + 0.25 + 0.29 + 0.01 + 0.71 + 1.02 + 0.98 + 0.63 0 Basic Series Serial number R5 (1) R 10 (2) R 20 (3) R 40 (4) 1.00 1.00 1.00 1.00 1.06 1.12 1.18 1.25 1.32 1.40 1.50 1.60 1.70 1.80 1.90 2.00 2.12 2.24 2.36 2.50 2.65 2.80 3.00 3.15 3.35 3.55 3.75 4,00 4.25 4.50 4.75 5.00 5.30 5.60 6.00 6.30 6.70 7.10 7.50 8.00 8.50 9.00 9.50 10.00 1.12 1.25 1.25 1.40 1.60 1.60 1.60 1.60 2.00 2.00 2.24 2.50 2.50 2.50 2.80 3.15 3.15 3.55 4.00 4.00 4.00 4.50 5.00 5.00 5.60 6.30 6.30 6.30 7.10 8.00 8.00 9.00 10.00 10.00 10.00 (5) 0 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 FROM ISO 497 — 1973 AMCA STANDARD 99-0098-76 Adopted 4-28-76 BASIC SERIES OF PREFERRED NUMBERS Supersedes AS-98-76 Reviewed 1983 U.S. Customary Units AMCA Standard (1) Metric (SI) Unit Conversion (4) Factor VOLUME FLOW cfm cubic meter per second ml/s 0.00047195 PRESSURE in. wg pascal Pa or N/m2 248.36 POWER hp watt W or J/s 745.70 TORQUE Ibf-in newton meter N•m 0.11298 DENSITY Ibm/ft 3 kilogram per cubic meter kg/m 3 16.018 SPEED (2) rpm 0.016667 VELOCITY fpm revolution per second rps meter per second m/s DIMENSIONS in. millimeter mm 25.400 MOMENT OF INERTIA Ibm-ft 2 kilogram meters squared k g • m2 0.042140 STRESS Ibf/in 2 pascal Pa or N/m2 6894.8 TEMPERATURE (3) °F kelvin (°F + 459.67)/1.8 0.0050800 Notes: (1) The choice of the appropriate multiple or sub multiple of an SI unit is governed by convenience. The multiple chosen for a particular application should be the one which will lead to numerical values within a practical range (i.e. kilopascal for Pressure, kilowatts for Power, megapascal for stress, and Iiters/second for volume flow.) (2) The second is the SI base unit of time. Although outside SI, the minute has been recognized by CIPM as necessary to retain for use because of its practical importance. (3) The kelvin is the SI base unit of thermodynamic temperature and is preferred for most scientific and technological purposes. The degree celsius (°C) is acceptable for practical applications. (4) Multiply “Customary” unit by this factor to obtain AMCA Standard, except for kelvin temperature. Supersedes AMS-100-76 Fan applications may involve the handling of potentially explosive or flammable particles, fumes or vapors. Such applications require careful consideration of all system components to insure the safe handling of such gas streams. This AMCA Standard deals only with the fan unit installed in that system. The Standard contains guidelines which are to be used by both the manufacturer and user as a means of establishing general methods of construction. The exact method of construction and choice of alloys is the responsibility of the manufacture however, the customer must accept both the type and design with full recognition of the potential hazard and the degree of protection required. TYPE CONSTRUCTION A All parts of the fan in contact with the air or gas being handled shall be made of nonferrous material. Steps must also be taken to assure that the impeller, bearings, and shaft are adequately attached and for restrained to prevents lateral or axial shift in these components. B The fan shall have a nonferrous impeller and nonferrous ring about the opening through which the shaft passes. Ferrous hubs, shafts, and hardware are allowed provided construction is such that a shift of impeller or shaft will not permit two ferrous parts of the fan to rub or strike. Steps must also be taken to assure that the impeller, bearings, and shaft are adequately attached and/or restrained to prevent a lateral or axial shift in these components. C The fan shall be so constructed that a shift of the impeller or shaft will not permit two ferrous parts of the fan to rub or strike. Notes 1. No bearings, drive components or electrical devices shall be placed in the air or gas stream unless they are constructed or enclosed in such a manner that failure of that component cannot ignite the surrounding gas stream. 2. The user shall electrically ground all fan parts. 3. For this Standard, non ferrous material shall be any material with less than 5% iron or any other material with demonstrated ability to be spark resistant. 4. The use of aluminum or aluminum alloys in the presence of steel which has been allowed to rust requires special consideration. Research by the U. S. Bureau of Mines and others has shown that aluminum impellers rubbing on rusty steel may cause high intensity sparking The use of the above Standard in no way implies a guarantee of safety for any level of spark resistance. “Spark resistant construction also does not protect against ignition of explosive gases caused by catastrophic failure or from any air stream material that maybe present in a system. ” This Standard applies to: Centrifugal Fans Axial and Propeller Fans Power Roof Ventilators This Standard applies to ferrous and nonferrous metals. The potential questions which may be associated with fans constructed of FRP, PVC, or any other plastic compound were not addressed. AMCA STANDARD 99-0401-86 CLASSIFICATIONS FOR SPARK RESISTANT CONSTRUCTION Adopted 2-12-86 Reviewed Supersedes 99-0401-82 1. This standard includes the following total static pressure classifications: Class A Total static pressure of 0 inches to 3 inches maximum of water gauge. Class B Total static pressure of 3 inches to 5.5 inches maximum of water gauge. Class C Total static pressure over 5.5 inches of water. 2. Total static pressure includes the internal static pressure losses. I I Adopted I AMCA STANDARD 99-1401-66 11-30-66 OPERATING LIMITS FOR CENTRAL STATION UNITS Supersedes 1401-66 Reviewed 1983 Notes: 1. SWSI = Single width, single inlet fan, DWDl = Double width, double inlet fan, 2. Precise outlet area, SWSl = .833 D2x10-6. Precise outlet area, DWDl = 1.5 D 2 X 10-6. 3. A fan conforming to this Standard shall not exceed the impeller diameter or maximum outlet area shown. Supersedes AM S-2001 -76 Impeller Diameter mm Maximum Inlet Diameter At Point Of Connection (Inside Diameter) C mm Maximum Outlet Area (Inside Dimensions) AxB m2 280 350 438 551 700 875 980 1103 1243 1400 1575 1750 1960 2188 2450 2800 160 200 250 315 400 500 560 630 710 800 900 1000 1120 1250 1400 1600 0.020 0.031 0.049 0.078 0.126 0.195 0.246 0.312 0.396 0.503 0.636 0.785 0.985 1.227 1.539 2.011 Notes: 1. Maximum impeller diameter = 1.75 x maximum inlet inside diameter. 2. Precise Outlet area = 3. A fan conforming to this standard shall not exceed the maximum inlet diameter or maximum outlet area shown. AMCA STANDARD 99-2002-82 METRIC DIMENSIONS FOR INDUSTRIAL CENTRIFUGAL FANS Adopted 9-26-82 Reviewed Supersedes AMS-2002.-6 Impeller Diameter D mm Maximum Outlet Area (Inside Dimensions) π r2 m2 315 400 500 630 800 900 1000 1120 1250 1400 1600 1600 2000 2240 2500 2800 3150 3550 0.149 0.240 0.375 0.595 0.960 1.215 1.500 1.662 2.344 2.940 3.840 4.660 6.000 7.526 9.375 11.760 14.644 18.904 Notes: 1. Precise outlet area = 1.5 x D 2 X 10-6. 2. A fan conforming to this Standard shall not exceed the impeller diameter or maximum outlet area shown. AMCA STANDARD 99-2003-82 METRIC IMPELLER DIAMETERS & OUTLET AREAS FOR TUBULAR CENTRIFUGAL FANS Adopted 9-26-82 Reviewed Supersedes AMS-2003-76 Notes 1. SWSI = Single width, single inlet fan, DWDI = Double width, double inlet fan. 2. Precise outlet area, SWSI = 0.00574967 x D2. Precise outlet area, DWDI = 0.01034941 x D2. 3. A fan conforming to this Standard shall not exceed the impeller diameter or maximum outlet area shown. Notes: 1. SWSI = Single width, single inlet fan. DWDI = Double width, double inlet fan. 2. Precise outlet area, SWSI = .828 x D2 x 10-6. Precise outlet area, DWDI = 1.490 x D 2 x 10-6. 3. A fan conforming to this Standard shall not exceed the impeller diameter or maximum outlet area shown. AMCA STANDARD 99-2401-82 PAGE 2 OF 2 IMPELLER DIAMETERS & OUTLET AREAS FOR CENTRIFUGAL FANS (METRIC EQUIVALENTS) Adopted 9-26-82 Reviewed Supersedes AS-2401-M-66 Notes: 1. Precise outlet area = 0.0018125 x D2. 2. A fan conforming to this standard shall not exceed the maximum inlet diameter or maximum outlet area shown. AMCA STANDARD 99-2402-82 PAGE 1 OF 2 Adopted 9-26-82 Reviewed DIMENSIONS FOR INDUSTRIAL CENTRIFUGAL FANS I Supersedes 2402-66 Impeller Diameter D mm Maximum Inlet Diameter At Point Of Connection (Inside Diameter) C mm Maximum Outlet Area (Inside Dimensions) A x B m2 486 575 663 752 836 927 1016 1146 1283 1461 1635 1809 1988 2165 2381 2648 279 330 381 432 483 533 584 660 737 838 940 1041 1143 1245 1372 1524 .062 .086 .115 .148 .183 .224 .269 .343 .429 .557 .696 .854 1.031 1.224 1.480 1.830 Notes: l. Precise outlet area = 0.261 X D2 X 10-6. 2. A fan conforming to this standard shall not exceed the maximum inlet diameter or maximum outlet area shown. AMCA STANDARD 99-2402-82 PAGE 2 OF 2 DIMENSIONS FOR INDUSTRIAL CENTRIFUGAL FANS (METRIC EQUIVALENTS) Adopted 9-26-82 Reviewed Supersedes AS-2402-M-66 SW - Single Width SI - Single Inlet DW - Double Width DI - Double Inlet Arrangements 1, 3, 7 and 8 are also available with bearings mounted on pedestals or base set Independent of the fan housing see 99-2406. For designation of rotation and discharge, see 99-2407. For motor position, belt or chain drive, see 99-2405. For designation of position of inlet boxes, ARR. 1 SWSI For belt drive or direct connection. Impeller overhung Two bearings on base ARR. 2 SWSI For belt drive or direct connection. Impeller overhung. Bearings in bracket supported by fan housing. ARR. 3 SWSI For belt drive or direct connection. One bearing on each side and supported by fan housing. ARR. 3 DWDI For belt drive or direct connection One bearing on each side and supported by fan housing. ARR. 4 SWSI For direct drive. impeller overhung on prime mover shaft. No bearings on fan. Prime mover base mounted or integrally directly connected. ARR. 7 SWSI For belt drive or direct connection, Arrangement 3 plus base for prime mover. ARR. 7 DWDI For belt drive or direct connection Arrangement 3 plus base for prime mover. ARR. 8 SWSI For belt drive or direct connection. Arrangement 1 plus extended base for prime mover. ARR. 9 SWSI For belt drive. impeller overhung, two bearings, with prime mover outside base. ARR. 10 SWSI For belt drive. impeller overhung, two bearings, with prime mover inside base. SW - Single Width SI - Single Inlet DW - Double Width DI - Double Inlet For designation of rotation and discharge, For motor position, belt or chain drive, For designation of position of inlet boxes, see 99-2406. see 99-2407. see 99-2405. ARR. 1 SWSI WITH INLET BOX For belt drive or direct connection. lmpelIer overhung, two bearings on base. Inlet box may be self-supporting. ARR. 3 SWSI WITH INDEPENDENT PEDESTAL For belt drive or direct connection fan. Housing is self-supporting, One bearing on each side supported by independent pedestals, ARR. 3 SWSI WITH INLET BOX AND INDEPENDENT PEDESTALS For belt drive or direct connection fan. Housing is self-supporting. One bearing on each side supported by independent pedestals with shaft extending through inlet box. ARR. 3 DWDI WITH INDEPENDENT PEDESTAL For belt drive or direct connection fan. Housing is self-supporting. One bearing on each side supported by independent pedestals. ARR. 3 DWDI WITH INLET BOX AND INDEPENDENT PEDESTALS For belt drive or direct connection fan. Housing is self-supporting. One bearing on each side supported by independent pedestals with shaft extending through inlet box. ARR. 8 SWSI WITH INLET BOX For belt drive or direct connection. lmpelIer overhung, two bearings on base plus extended base for prime mover. Inlet box may be self-supporting. Notes: 1. Reference line is the top vertical axis through center of fan shaft. 2. Position of inlet box and air entry to inlet box is determined from DRIVE SIDE OF FAN. 3. Position of inlet box is designated in degrees clockwise from top vertical axis as shown, and may be any intermediate angle as required. 4. Positions 135° to 225° in some cases interfere with floor structure. Notes: 1. Direction of rotation is determined from drive side of fan. 2. On single inlet fans, drive side is always considered as the side opposite fan inlet. 3. On double inlet fans with drives on both sides, drive side is that with the higher powered drive unit. 4. Direction of discharge is determined in accordance with diagrams. Angle of discharge is referred to the vertical axis of fan and designated in degrees from such standard reference axis. Angle of discharge may be any intermediate angle as required, 5. For fan inverted for ceiling suspension, or side wall mounting, direction of rotation and discharge is determined when fan is resting on floor. AMCA STANDARD 99-2406-83 DESIGNATIONS FOR ROTATION AND DISCHARGE OF CENTRIFUGAL FANS Supersedes 2406-66 Adopted 2-22-83 Reviewed Location of motor is determined by facing the drive side of fan and designating the motor positions by letters W, X, Y, or Z as the case may be. AMCA STANDARD 99-2408-69 PAGE 1 0F 5 OPERATING LIMITS FOR SINGLE WIDTH CENTRIFUGAL FANS– Ventilating Airfoils & Backwardly Inclined. Supersedes 2408-69 Adopted 10-20-69 Reviewed 1983 AMCA STANDARD OPERATING LIMITS FOR DOUBLE WIDTH CENTRIFUGAL FANS– 99-2408-69 Ventilating Airfoils & Backwardly Inclined. PAGE 2 OF 5 Supersedes 2408-69 Adopted 10-20-69 Reviewed 1963 AMCA STANDARD 99-2408-69 PAGE 5 OF 5 OPERATING LIMITS FOR CENTRIFUGAL FANS — Tubular. Supersedes 2406-69 Adopted 10-20-69 Reviewed 1983 the outlet of the fan and resting location 180 on the floor as shown for Arrangement 9. Arrangements 4 and 9 can be furnished with supports for floor, wall or ceiling mounting. The position of these supports determines which motor locations are available for motor placement. Generally motor locations 135, 180, and 225 are not available on floor, wall or inverted ceiling-mounted fans and motor locations 45, 90,270 and 315 may not be available for ceiling-hung fans. Another method of mounting vertical fans is shown in the view on the right. Specify fan to be furnished with ceiling-mounting brackets, floor-mounting brackets or both. AMCA STANDARD 99-2410-82 DRIVE ARRANGEMENTS FOR TUBULAR CENTRIFUGAL FANS Supersedes 2410-66 Adopted 9-26-82 Reviewed Notes: 1. Precise outlet area = 0.01034941 x D2. 2. A fan conforming to this Standard shall not exceed the impeller diameter or maximum outlet area shown. AMCA STANDARD 99-2411-82 PAGE 1 OF 2 IMPELLER DIAMETERS & OUTLET AREAS FOR TUBULAR CENTRIFUGAL FANS Supersedes 2411-69 Adopted 9-26-82 Reviewed Impeller Diameter D mm 311 343 381 419 464 508 565 622 686 762 838 927 1022 Maximum Outlet Area (Inside Dimensions) m2 .144 .175 .216 .262 .320 .365 .476 .577 .701 .865 1.047 1.281 1.682 Impeller Diameter D mm Maximum Outlet Area [Inside Dimensions) m2 1130 1245 1376 1524 1676 1654 2051 2261 2496 2762 3048 3366 1.904 2.308 2.629 3.461 4.187 5.1,23 6.268 7.614 9.280 11,369 13.843 16.877 Notes: 1. Precise outlet area = 1.490 x D2 x 10-8. 2. A fan conforming to this Standard shall not exceed the impeller diameter or maximum outlet area shown. AMCA STANDARD 99-2411-82 PAGE 2 OF 2 IMPELLER DIAMETERS & OUTLET AREAS FOR TUBULAR CENTRIFUGAL FANS (METRIC EQUIVALENTS) Adopted 9-26-82 Reviewed Supersedes AS-2411-M-69 This standard is not limited to the range of sizes listed. Smaller and larger fan sizes conforming to the R20 series, with the 1000mm size as a base, may be included. I.D.1 is a fan size conforming to the R20 series of sizes and is equal to the casing I.D. I.D. 2 is a transition inside diameter conforming to the R40 series of sizes with a 1000mm base. The included angle of divergence or convergence is recommended to not exceed 15 degrees but is not limited by this standard. AMCA STANDARD 99-3002-76 METRIC DIMENSIONS FOR AXIAL FAN TRANSITIONS Adopted 10-19-76 Reviewed 1983
