ANSI/AMCA ANSI/ASHRAE Laboratory Methods of Testing Fans for Certified Aerodynamic Performance Rating An American National Standard. ARLINGTON HEIGHTS, Ill., September 12, – The Air Movement and Control Association. (AMCA) International Inc. announces the revision of ANSI/AMCA. Application: Airflow Test Chamber or Test Duct,Nozzle for measurement of fluid flow. Standards: ANSI/AMCA ,ANSI/ASHRAE , ISO , GB/T
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AMCA – Free Download PDF
The results of a fan test are a complex combination of variables which must be presented graphically according to the standard. Edge of hole shall be square and free from burrs. When pressure response times snsi long, inspect for possible blockage. Variable exhaust system may be an auxiliary fan or a throttling device.
Averaging can be accomplished mentally if the fluctuations are small and regular. The volumetric airflow rate at fan air amfa. The origin of these formulae will be obvious to an engineer.
The Reynolds number Re based on anxi hydraulic diameter Dh in m ft shall be calculated from: The mass per unit volume of air. Barometric pressure shall be listed when fan pressure exceed 2. The macro-pattern of the surface shall not exceed 0.
The total pressure in an inlet chamber may be sensed with a stationary tube of the proportions and requirements shown in Figure 2B. The ratio of fan power output to fan power input.
ANSI/AMCA – Laboratory Methods of Testing Fans for Certified Aerodynamic
These laws may be deduced from similarity considerations, dimensional analysis, or various other lines of reasoning. It incorporates a flow straightener per Figure 6B and a pressure measurement station one diameter from the exit end. Complete kinematic similarity requires that the ratios of all corresponding velocities for the two fans be equal. Analysis of fan power input is unnecessary since it is a part of efficiency analysis.
Substituting and rearranging gives: Typical fan performance curves are shown in Figure On the inlet duct setup, ts1 is equal to td3 and Pt1 may be considered equal to Pt3 for fan air density calculations. The specifications regarding accuracy correspond to two standard deviations based on an assumed normal distribution. AMCA  ibid, p absi The ratio of equivalent length Amcq of a straightener to hydraulic diameter Dh shall be determined from the elemental thickness y and the equivalent diameter D using: A duct connected to the upstream side of a flow nozzle shall be between 6.
The fan performance between the markers can be estimated anei a curve or line. The cross-section of amcs elliptical portion is one quarter of an ellipse, having the large axis D and the small axis 0. Any bi-stable performance points airflow rates at which two different pressure values can be measured shall be reported. The unit of length is the meter m or millimeter mm ; I-P units are the foot ft or inch in. A duct with a plane for pressure measurement shall be straight and may have either a uniform circular or rectangular cross-section.
The fan total efficiency multiplied by the snsi of fan static pressure to fan total pressure. Report and Results of Test. At the entrance of the throat the mean may be 0. If the fan has more than one impeller, fan rotational speed is the rotational speed of each impeller.
Averaging can be accomplished mentally if the fluctuations are small and regular.
ANSI / Amca 210-07 Airflow Chamber, Airflow Duct, Fluid Flow Measurement
A flow nozzle without an integral throat tap may be used in a multiple nozzle chamber, in which case, upstream and amva pressure taps shall be located as shown in the figure for the appropriate setup. The torque measured on any instrument will fluctuate with time.
The larger size is helpful in preventing blockage due to dust, water, ice, etc. Hg and readable to 34 Ansk 0. The recommended approximation which meets these requirements is shown in Figure 4B by Cermak, J. Since the velocity determination depends on Reynolds Number, an approximation must be employed.
The area A6 is measured at the plane of the throat taps, or the nozzle exit amac nozzles without throat taps. A pre-test uncertainties analysis is not required for each test covered by this standard because it is recognized that most laboratory tests for anis are conducted in facilities where similar tests are repeatedly run.
The degree of similarity of the performance characteristics will depend on the degree of similarity of the fans and of the airflow through the fans. Since flow rate is proportional to air velocity times flow area, and since area is asi to the square of any dimension, say impeller diameter Dit follows that the fan law equation for fan airflow rate Q is: The fan airflow rate may be calculated from velocity pressure measurements Pv3 taken by Pitot traverse.
Thank you for interesting in our services. An airflow straightener shall be used in any duct that provides a measurement plane. Hg, shall be used only for barometric pressure measurements.
Complete geometric similarity a,ca that the ratios of all corresponding dimensions for the two fans be equal. The description of the test fan shall be recorded. The airflow rate Q3 at the Pitot traverse plane shall be obtained from the velocity V3 and the area A3 using: The nozzle surface in the direction of flow from the nozzle inlet towards the nozzle exit shall fair smoothly so that a straight-edge may be rocked over the surface without clicking.
Connecting ducts and elbows of any size and shape may be used 10 5.
An uncertainty analysis based on this curve and the maximum allowable measurement tolerances follows: Efficiency is based on a per-unit basis. However, that ajsi is not considered sufficiently documented to incorporate any rules in this Annex.