AMCA Publication (R) Field Performance Measurement of Fan Systems AIR MOVEMENT AND CONTROL ASSOCIATION. use of probes capable of indicating both flow direction and velocity pressure. The AMCA Publication ‘Field Performance. Measurements’ and the AMCA. AMCA International has reaffirmed AMCA Publication. , Field Performance Measurement of Fan Systems. Recommendations in this publication may be.
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Select a manometer that will provide an acceptable degree of accuracy; consider the range, slope, quality, scale graduations, indicating fluid of the instrument and the range of the velocity pressures to be measured. A major problem of testing in the field is the difficulty of finding suitable locations for making accurate measurements of flow rate and pressure.
Motor efficiency data supplied by motor manufacturer. Determine Ps5 in a similar manner. However, due to the turbulence existing in the regions of the outlets of the fans, it is recommended that static pressure taps be used at Planes 1b-2a and 2b.
The duct, temporarily installed for purposes of the test, is square in cross-section, with side dimension of 1. The most obvious problem is the lack of a suitable location for the velocity pressure measurement plane. Precautions The following precautions should be observed when conducting a field test: The density at Planes 1 and 4: Determine Ps1 by using a Pitot-static tube or static pressure taps in the duct connection at the fan inlet.
The sum of the static pressure, Ps1, and velocity pressure, Pv1, at the inlets of a fan with unrestricted inlets is considered to be equal to the sum of the static pressure, Psx, and the velocity pressure, Pvx, at a point sufficiently distant from the fan inlets as to be in still air. This will eliminate the uncertainties involved in the determination of the pressure losses, and the equations for Ps1 and Ps2 reduce to the following: In order to calculate the value of SEF 1, it is necessary to measure the length of the outlet duct, L; the fan outlet area, A2; and the blast area of the fan.
Measure td5 in Plane anca. Two equations can be used in estimating the motor power output. This consideration arises when a damper, which is not considered a part of the fan is located between a static pressure measurement plane and the fan. Also, the temperature of the cooling coil must be kept constant throughout the test period. Determine Ps4 by averaging the static pressure measurements made in a traverse of Plane 4.
Motor performance data, supplied by the motor manufacturer, are used in the determination of motor power output in this example. Use no fewer than four taps located 90 degrees apart.
Measure td1 and td2.
AMCA Publication R – Free Download PDF
The uncertainty analyses in Annex T and the resulting anticipated uncertainty range do not account for uncertainties that may occur in the following: Due to practical limitations in length, its use is restricted to measurements where the velocities are very low.
In addition, the judgments required in determining the values of the SEFs are susceptible to error. Each velocity pressure measurement should be mentally averaged on a time-weighted basis.
This is particularly important at measurement points near the walls of the airway see Annex A-1A. A Pitot traverse plane suitable for the measurements used to determine flow rate are as follows: Ideally, these two points will coincide at the same cfm. For a blast area ratio of 0.
Measure the fan speed and the motor amps, volts, and if possible, watts. For fpm inlet velocity and curve V, Figure 7. AMCA R 3 Install a duct on the inlet side of the fan for the purpose of providing a location for the velocity pressure measurement plane. The actual ampsload characteristics for motors of the same horsepower rating can vary greatly from motor manufacturer to motor manufacturer. For Plane 2 publicafion of: The shape and area of the duct cross-section were selected on the basis of minimizing the effect of the duct on the performance of the fan while providing velocity pressure readings of measurable magnitudes.
The fan assembly, as supplied and rated by the manufacturer, includes the inlet box and diffuser section, but does not include the silencer.
AMCA Publication 203-90 (R2007), “Field Performance Measurement of Fan…
These static pressure measurements are designated Ps4 and Ps5, respectively. These equations can be used for gases other than air and can be adapted for use in calculations involving any two planes, subject to the limitations noted earlier.
Measure the fan publiction and motor amps, volts, and if possible, watts.
Fan Power Input The alternative to dealing with a large magnitude SEF is to eliminate its source. Plane of fan outlet Plane 3: C Proof of Performance Test – A test in response to a complaint to maca that the fan is meeting the specified performance requirement. Manometer fluids other than water are acceptable, provided the specific gravity is known.
Not pbulication of the possible fan-system combinations are included in the examples, but it is expected that the examples will provide sufficient guidance for dealing with those cases not covered. A temporary short duct is installed upstream of the silencer to establish Plane 3 in which more uniform pressures can be obtained.