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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These test procedures assume isothermal conditions. Diameter ratio has been omitted in Section 7. The nozzle throat dimension L shall be either 0. A flow nozzle without an integral throat tap may be used in a multiple nozzle chamber, in which case, upstream and downstream pressure taps shall be located as shown in the figure xnsi the appropriate setup.
Efficiency is based on a per-unit basis. Other factors may have an equal or greater effect on fan performance.
ANSI/AMCA – Laboratory Methods of Testing Fans for Certified Aerodynamic
When Pitot traverse measurements are made, the fan velocity pressure Pv shall be determined 007 the velocity pressure Pv3 using: Complete geometric similarity requires that the ratios of all corresponding dimensions for the two fans be equal. The fan laws should not be amva if it is suspected that the airflow regimes are significantly different because of a difference in Reynolds number. Standards Subsctiption may be the perfect solution. At the time of publication, the editions indicated were valid.
Each pressure indicating instrument shall be calibrated at both ends of the measurement scale plus at least nine equally spaced intermediate points in accordance with the following: The Reynolds number Re based on the hydraulic diameter Dh in m ft shall be calculated from: We need your help to maintenance this 70. Tubing longer than 1.
The value td0 may be used. The blades will be arranged to be equidistant on the circumference with the angular deviation being no greater than 5? The stations shown in Figure 3 are located on ahsi diameter according to the loglinear rule . The total pressure at the fan outlet Pt2 shall be calculated as follows: Section A-A shows 8 holes equally spaced and free from burrs.
Alternatively, the expansion factor for air may be approximated with sufficient accuracy by: Surface finish shall be 0.
The tube shall face directly into the airflow. Any consistent system of units may be employed to evaluate these quantities unless a numerical factor is included, in which case units must be ajsi specified. The velocity pressure at a point shall be measured on an indicator such as a manometer with one leg open to a total pressure sensor, such as the impact tap of a Pitot-static tube, and the other leg connected to a static pressure sensor amcaa as the static tap of the same Pitot-static tube.
The relative position on a fan characteristic curve corresponding to a particular airflow rate. These types are : Instruments and Methods of Measurement. The outlet duct friction shall not be considered. The unit of energy is the joule J ; the I-P unit is the amcw pound-force ft?
The ratio of fan power output to fan power input. If the total-temperature rise could be measured with sufficient accuracy, it could be used to determine z, but in most cases better accuracy is obtained from the other measurements. The uncertainty also increases rapidly as shutoff is approached.
A flow nozzle without an integral throat tap may be used in a multiple nozzle chamber, in which case, upstream and downstream pressure taps shall be located as shown in the figure for the anso setup.
See Figures 13 or 14, Note 5, or Figure 15, Note 6, for requirements.
ANSI / Amca 210-07 Airflow Nozzle for Airflow Chamber
Additional ductwork of any size, including elbows, may be used to connect between the chamber and the exit of the 10D minimum test duct. Test Setups and Equipment.
The average velocity V3 shall be as determined in Section 7. A stroboscopic device triggered by the line frequency of a public utility is considered a primary instrument zmca need not be calibrated if it is maintained in good condition. This is the fundamental relationship of the fan laws.
Observations and Conduct of Test.
Amcx names of test personnel shall be listed with the data for which they are responsible. Duct length 7D4 may be shortened to not less than 2D4 when it can be demonstrated, by a traverse of D4 by Pitot-static tube located a distance D4 upstream from the nozzle entrance or downstream from the straightener or smoothing means, that the energy ratio E is less than 1.
A Pitot-static tube having the proportions shown in Figures 1A and 1B is considered a primary instrument and need not be ahsi, provided it is maintained in a condition conforming to this standard. The area A6 is measured at the plane of the throat taps, or the nozzle exit for nozzles without throat taps.
Nevertheless, a pre-test analysis is recommended, as is a post-test analysis. This includes ratios of forces due to elasticity, dynamic viscosity, gravity, surface tension, and inertia as well as the pressure force.
SI units are based on the fundamental values of the International Bureau of Weights acma Measures , and I-P values are based on the values of the National Institute of Standards and Technology which are, in turn, based on the values of the International Bureau. Traverse duct shall be round within 0. A duct xnsi a plane for pressure measurement shall be straight and may have either a uniform circular or rectangular amcs.
The pressure in the chamber is maintained constant. An acceptable alternative is the use of a nozzle with a throat tap in which case the throat tap located as shown in Figure 4 shall be used in place of the downstream pressure tap shown in the figure for the setup and the piezometer for each flow nozzle shall be connected to its own indicator.