Standard and ANSI/ASHRAE Standard 51, except as modified by Units shall be tested in accordance with ANSI/AMCA Standard /ANSI/ASHRAE. Standard — Laboratory Methods of Testing Fans for Aerodynamic Performance Rating (ANSI/AMCA Standard ) (ANSI/ASHRAE Approved). and Air-Conditioning Engineers (ASHRAE) approved ANSI/AMCA Standard ANSI/ASHRAE Standard , Laboratory Methods of Testing Fans for.
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Performance plots shall be drawn with the fan airflow rate as abscissa. The number of determinations required to establish the performance of a fan over the range from shut-off to free delivery will depend upon the shape of the characteristic curve of the fan under test.
To avoid excessive pressure drop through the airflow straightener, careful attention to construction tolerances and details is important . Report and Results of Test 8. The adjacent arcs, as well as the last arc, shall smoothly meet and blend with the nozzle throat.
Any consistent system of units may be employed to evaluate these quantities unless a numerical factor is included, in which case units must be as specified.
If any of the criteria are not met, the design of the settling means must be altered, and all testing restarted. Once the airflow settling means have demonstrated that all applicable test criteria have been met, the chamber can be used for all future testing within the limits defined by the test criteria. The interfaces between a fan and the remainder of the air system; the respective planes perpendicular to an airstream entering or leaving a fan.
Dimensions should be checked against a drawing and a copy of the drawing attached to the recorded data. Deviations may also be due to conditions affecting the flow into or out of the fan which, in turn, affects the ability of the fan to perform. Report and Results of Test. Pt, Pt1, pb, H, and Q are all test values.
Groups approve laboratory methods for testing fans.
It can be assumed that the tests taken in this condition with the nonverified settling means are sufficiently accurate to be used to establish acceptance criteria for all Annex A testing. Connecting tubing to pressure indicator shall be 6 mm 0. When the tested fan or a pressure measurement plane is located downstream of the settling means, the purpose of the settling means is to provide a ashrxe uniform flow ahead of the tested fan or pressure measurement plane.
Chamber Leakage Rate Test Procedure Informative The volume of interest is the volume between the measurement plane and the air moving device.
AMCA Airflow Nozzle manufacturers – ec
There is some evidence that efficiency improves with an increase in Reynolds number. Additional ductwork of any size including elbows may be used to connect between the chamber and the exit of the 10D minimum test duct. The value td0 may be used. Averaging can be accomplished mentally if the fluctuations are small and regular.
Generally, several screens in each airflow settling means will be required. The fan power output Ho would be proportional to the product of fan airflow rate Ashtae and fan total pressure Pt if air were incompressible.
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If the settling means are too restrictive, excessive backflow will result. Since the air velocity in an inlet chamber is considered uniform due to the settling means employed, a single measurement is representative of the average chamber pressure. The sample analysis given in Annex F calculates zshrae uncertainty in each of the fan performance variables, and in addition, combines certain ones into a characteristic uncertainty and others into an efficiency uncertainty.
The dimension M in the test setup diagram is the inside diameter of a circular chamber or the equivalent diameter of dimensions a and b, where: Efficiency is based on a per-unit basis. The geometry of the common segments used for testing on the outlet side of the fan is defined in Figures 18, 19 and However, it is possible to perform an uncertainty analysis to identify a range of values within which the true value probably lies.
Cell sides shall be flat and straight. One or more supply systems, each with its own nozzle, may aahrae used.
The characteristic uncertainty can be defined with reference to the following diagram: The unit of energy is the joule J ; the I-P unit is the foot pound-force ft? Where appropriate, lowest expected barometer and temperature for a laboratory at sea level are assumed. A pressure tap is sensitive only to the pressure in the immediate vicinity of sshrae opening.