1、ANSI/AMCA Standard 208-18An American National StandardApproved by ANSI on January 24, 2018Air Movement and Control Association InternationalAMCA Corporate Headquarters30 W. University Drive, Arlington Heights, IL 60004-1893, USAcommunicationsamca.org nPh: +1-847-394-0150 nwww.amca.org 2018 AMCA Inte
2、rnational and ASHRAECalculation of the Fan Energy IndexSTANDARDANSI/AMCA Standard 208-18 Calculation of the Fan Energy Index Air Movement and Control Association International 30 West University Drive Arlington Heights, Illinois 60004 AMCA Publications Authority AMCA Standard 208-17 was adopted by t
3、he membership of the Air Movement and Control Association International Inc. on November 22, 2017. It was approved as an American National Standard on January 24, 2018 Copyright 2018 by the Air Movement and Control Association International Inc. All rights reserved. Reproduction or translation of an
4、y part of this work beyond that permitted by Sections 107 and 108 of the United States Copyright Act without the permission of the copyright owner is unlawful. Requests for permission or further information should be addressed to the executive director, Air Movement and Control Association Internati
5、onal Inc. at 30 West University Drive, Arlington Heights, IL 60004-1893 U.S. Objections The Air Movement and Control Association (AMCA) International Inc. will consider and take action upon all written complaints regarding its standards, certification programs or interpretations thereof. For informa
6、tion on procedures for submitting and handling complaints, write to AMCA International 30 West University Drive Arlington Heights, IL 60004-1893 U.S.A. European AMCA Avenue des Arts, numro 46 Bruxelles (1000 Bruxelles) Asia AMCA Sdn Bhd No. 7, Jalan SiLC 1/6, Kawasan Perindustrian SiLC Nusajaya, Muk
7、im Jelutong, 79200 Nusajaya, Johor Malaysia Disclaimer AMCA uses its best efforts to produce publications for the benefit of the industry and the public in light of available information and accepted industry practices. However, AMCA does not guarantee, certify or assure the safety or performance of
8、 any products, components or systems tested, designed, installed or operated in accordance with AMCA publications or that any tests conducted under its publications will be non-hazardous or free from risk. Review Committee Tim Mathson (Chair) Greenheck Fan John Bade Johnson Controls Joanna Mauer App
9、liance Standards Awareness Project Sarah Widder Pacific Northwest National Lab Jason Meinke Phillips and Temro Industries Kai Aschenbach Ziehl-Abegg Justin Lim Northern Blower Inc. Z. Patrick Chinoda Revcor, Inc. Fernando A. Ruiz Equipos Electromecanicos, S.A. de C.V. Rae Jane Araujo Howden American
10、 Fan Adam Sterne Acme Engineering that is, airflow enters and exits the impeller parallel to the shaft axis (i.e., with a fan flow angle less than or equal to 20 degrees). Blades can either be single thickness or airfoil shaped. 3.1.2.2 Centrifugal impeller An impeller with a number of blades extend
11、ing between a back plate and shroud in which airflow enters axially through one or two inlets and exits radially at the impeller periphery. The airflow exits either into open space or into a housing with a fan flow angle greater than or equal to 70 degrees. Impellers can be classified as single inle
12、t or double inlet. Blades can be tilted backward or forward with respect to the direction of impeller rotation. Impellers with backward tilted blades can be ANSI/AMCA Standard 208 | 10 airfoil shaped (AF), backward curved single thickness (BC), backward inclined single thickness flat (BI) or radial
13、tipped (RT). Impellers with forward tilted blades are known as forward curved (FC). 3.1.2.3 Radial impeller A form of centrifugal impeller with a number of blades extending radially from a central hub in which airflow enters axially through a single inlet and exits radially at the impeller periphery
14、 into a housing with impeller blades positioned such that the outward direction of the blade at the impeller periphery is perpendicular within 25 degrees to the axis of rotation. Impellers can optionally have a back plate and/or shroud. 3.1.2.4 Mixed flow impeller An impeller with construction chara
15、cteristics between those of an axial and centrifugal impeller with a fan flow angle greater than 20 degrees and less than 70 degrees. Airflow enters axially through a single inlet and exits with combined axial and radial directions at a mean diameter greater than the inlet. 3.1.2.5 Fan flow angle Th
16、e angle of the centerline of the air-conducting surface of a fan blade measured at the midpoint of its trailing edge with the centerline of the rotation axis, in a plane through the rotation axis and the midpoint of the trailing edge. 3.1.3 Fan types 3.1.3.1 Centrifugal housed fan A fan with a centr
17、ifugal or radial impeller in which airflow exits into a housing that is generally scroll shaped to direct the air through a single fan outlet. Inlets and outlets can optionally be ducted. 3.1.3.2 Centrifugal inline fan A fan with a centrifugal impeller in which airflow enters axially at the fan inle
18、t and the housing redirects radial airflow from the impeller to exit the fan in an axial direction. Inlets and outlets can optionally be ducted. 3.1.3.3 Centrifugal unhoused fan A fan with a centrifugal impeller in which airflow enters through a panel and discharges into free space. Inlets and outle
19、ts are not ducted. This fan type also includes fans designed for use in fan arrays that have partition walls separating the fan from other fans in the array. 3.1.3.4 Power roof/wall ventilator (PRV) A fan with an internal driver and a housing to prevent precipitation from entering the building. It h
20、as a base designed to fit over a roof or wall opening, usually by means of a roof curb. 3.1.3.5 Centrifugal PRV exhaust A PRV with a centrifugal impeller that exhausts air from a building. Inlets are typically ducted, but outlets are not ducted. 3.1.3.6 Centrifugal PRV supply A PRV with a centrifuga
21、l impeller that supplies air to a building. Inlets are not ducted, and outlets are typically ducted. 3.1.3.7 Axial PRV A PRV with an axial impeller that either supplies or exhausts air to a building. Inlets and outlets are typically not ducted. 3.1.3.8 Axial inline fan A fan with an axial impeller a
22、nd a cylindrical housing with or without turning vanes. Inlets and outlets can optionally be ducted. 3.1.3.9 Axial panel fan A fan with an axial impeller mounted in a short housing that can be a panel, ring or orifice plate. The housing is typically mounted to a wall separating two spaces and the fa
23、ns are used to increase the pressure across this wall. Inlets and outlets are not ducted. ANSI/AMCA Standard 208 | 11 3.1.3.10 Laboratory exhaust fan A fan designed specifically for exhausting contaminated air vertically away from a building. Fan outlets are typically constricted to achieve a high o
24、utlet velocity. Induced flow lab exhaust fans use their high velocity discharge to entrain additional air to mix with contaminated building exhaust air. Inlets can optionally be ducted, and outlets are not ducted. 3.1.3.11 Jet fan A fan used for producing a high velocity flow of air in a space. Typi
25、cal function is to add momentum to the air within a tunnel. Inlets and outlets are not ducted. 3.1.3.12 Circulating fan A fan used for moving air within a space that has no provision for connection to ducting or separation of the fan inlet from its outlet. It is designed to be used for the general c
26、irculation of air. 3.1.3.13 Crossflow fan A fan with a housing that creates an airflow path through the impeller in a direction at right angles to its axis of rotation and with airflow both entering and exiting the impeller at its periphery. Inlets and outlets can optionally be ducted. 3.1.3.14 Fan
27、array A common application of fans using multiple fans in parallel between two plenum sections for a factory packaged or field erected air handling unit. 3.2 Symbols Symbol Description SI Unit I-P Unit A Fan outlet or discharge area m2ft2A, B, C, D, E Constants dimensionless Ft Force due to thrust,
28、jet fans N lbf FEIt,i Fan energy index, fan total pressure basis, at duty point i dimensionless FEIs,i Fan energy index, fan static pressure basis, at duty point i dimensionless FEPref Fan electrical input power, reference kW kW FEPact Fan electrical input power, actual kW kW Hi,ref Fan shaft power,
29、 reference kW hp Hi,act Fan shaft power, actual kW hp Ht,ref Motor output power, reference kW hp Ht,act Motor output power, actual kW hp Ht,def Motor output power, default kW hp Po Pressure constant Pa in. wg Ps,i Fan static pressure at duty point i Pa in. wg Pt,i Fan total pressure at duty point i
30、Pa in. wg Qi Fan airflow at duty point i m3/s cfm Q0 Airflow constant m3/s cfm 0 Fan efficiency constant dimensionless trans,ref Transmission efficiency, reference dimensionless trans,act Transmission efficiency, actual dimensionless mtr,ref Motor efficiency, reference dimensionless mtr,act Motor ef
31、ficiency, actual dimensionless ANSI/AMCA Standard 208 | 12 ctrl,ref Motor controller efficiency, reference dimensionless Fan air density kg/m3lbm/ft3std Standard air density g/m3lbm/ft34. General 4.1 Minimum testable configuration The FEI calculation is based on fan performance derived from tests in
32、 accordance with recognized fan test standards. See Annex A to determine the appropriate test standard for each fan type. These test standards each require some minimum configuration in order to run the tests. This standard is also based on tests of fans in at least a minimum testable configuration,
33、 including the following: 1. Impeller 2. Shaft and bearings and/or motor to support the impeller 3. Structure or housing, unless the fan does not require these (e.g., an unshrouded circulating fan) 4.2 FEI pressure basis The FEI is calculated using either fan total pressure or fan static pressure, b
34、ased on the fan type. See Annex A for a complete explanation of the pressure basis and to learn which pressure to use. 4.3 Appurtenances Certain accessories or appurtenances can be used to improve fan performance, including but not limited to inlet bells, diffusers, stators or guide vanes. The effec
35、t of these appurtenances can be included in the FEI calculation only if they were present during the test and are supplied with the fan. Test ducts included during testing are not required to be supplied with the fan. Other appurtenances placed at or near the fan inlet or discharge will often result
36、 in reduced overall fan performance. These include but are not limited to guards, dampers, filters or weather hoods. The effect of these appurtenances on fan performance can be tested and published to aid in fan selection, but it is not included in the fan test used to determine FEI. As illustrated
37、in Figure 1, the reduced performance of a fan with appurtenances (the curve labeled 2) can be published and matched against system pressures in order to make proper fan selections. The process of fan selection includes determining the fan speed and/or blade pitch needed to achieve the required syste
38、m pressure (Preq) at the required airflow (Qreq) (point B in Figure 1). Once the required fan speed and/or blade pitch are determined, the FEI is determined from the standalone fan performance (the curve labeled 1 in Figure 1) at the same airflow, fan speed and blade pitch (point A in Figure 1). ANS
39、I/AMCA Standard 208 | 13 Figure 1Fan Curves at Constant RPM and Blade Pitch 4.4 Fans embedded in other equipment This standard does not apply to fan performance when tested embedded inside of other equipment. However, the standard can be used to calculate FEI for a fan that, while tested in a standa
40、lone configuration, will be embedded into other equipment. As with appurtenances and referring to Figure 1, corrections may need to be applied to the standalone fan performance data to account for a difference between how the fan was tested and how it is applied. The FEI for the embedded fan is dete
41、rmined from the standalone fan performance at the same airflow, fan speed and blade pitch of the fan as embedded in the equipment. See Annex D for detailed guidance on the conversion of standalone fan performance to that of an embedded fan. Each rated fan model must be rated according to the applica
42、ble fan type listed in Table A.2 of Annex A, as defined in Section 3, in accordance with with how that fan is distributed in commerce. For example, if a fan meets the definition of a PRV, it must be rated as a PRV with all necessary appurtenances, and performance ratings for a standalone centrifugal
43、 or axial fan used inside a PRV must not be used to describe the performance of the PRV itself. 5. Fan Energy Index 5.1 General The fan energy index (FEI) is defined as a ratio of the electrical input power of a reference fan to the electrical input power of the actual fan for which the FEI is calcu
44、lated, both calculated at the same duty point, i, which is characterized by a value of airflow (Qi) and pressure (Pt,i or Ps,i). FEI can be calculated for each point on a fan curve. nullnullnullnull,nullor nullnullnullnull,nullnullnullnullnullnullnullnullnullnullnull nullnullnull nullnullnullnullnul
45、lnullnullnullnullnull nullnullnullnullnull nullnullnullnullnullnullnullnullnullnullnull nullnullnull nullnullnullnullnullnullnullnullnullnull nullnullnullnullnull nullnullnullnullnullnullnullnullnullnullnullnull,nullnullnullnullnullnullnull,nullEq. 5.1 ANSI/AMCA Standard 208 | 14 5.2 Reference fan e
46、lectrical input power The reference fan concept is used to normalize the FEI calculation to a consistent power level independent of fan type, fan drive components or any regulatory requirements. The reference fan electrical input power is a function of airflow and fan pressure. The reference fan is
47、defined as one that requires a certain reference fan shaft power, uses a V-belt drive, has a motor efficiency based on the IE3 level for a four-pole 60 Hz motor and does not have a speed control. nullnullnullnullnullnull,nullnullHnull,nullnullnullnullnullnullnullnullnullnullnull,nullnullnullnullnull
48、nullnullnullnullnull,nullnullnullnullnullnullnullnullnullnullnull,nullnullnullnull Eq. 5.2 SI nullnullnullnullnullnull,nullnullHnull,nullnullnullnullnullnullnullnullnullnullnull,nullnullnullnullnullnullnullnullnullnull,nullnullnullnullnullnullnullnullnullnullnull,nullnullnullnull null 0.7457 Eq. 5.2
49、 I-P 5.2.1 Reference fan shaft power The reference fan shaft power, Hi,ref, is calculated either on a fan total pressure basis or a fan static pressure basis, depending on the fan type. See Annex A for a complete description and a list of fan types and the FEI pressure basis. 5.2.1.1 Total pressure basis For fans identified in Annex A as using a total pressure basis, the reference fan shaft power at a given duty point is a function of airflow (Qi) and fan total pressure (Pt,i) at that duty point. It is calculated according to the following equation: Hnull,nullnullnull
