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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However, usually they will not coincide and should be averaged to determine the fan airflow rate. These examples provide sufficient guidance for the proper field testing of most fan system installations. In locating Plane 3 downstream of the scrubber, changes in the composition of the air as a result of the action of the scrubber are properly taken into account in the determination of fan air flow rate.
A,ca these cases, the calculation of the loss is based on the performance ratings for the damper. These pkblication are used in the determination of densities at the various planes of interest. Publicatiob distance is 2.
The phase current method is convenient and sufficiently accurate for most field tests. The duct, temporarily installed for purposes of the test, is square in cross-section, with side dimension of 1.
Since the results of field tests are usually compared to the rated performance characteristics of the fan, field test values of fan power input should be determined on the same basis as that used in the fan ratings.
In situations such as this example, the air may be discharging from the duct into a region in which the atmospheric pressure publicatipn somewhat different from that to which all other pressure measurements are referred.
AMCA Publication 203 R2007
SEF 2 is due to the effect of insufficient length of duct between the fan outlet and the elbow downstream of the fan. On occasion, an undesirable traverse plane location is unavoidable, or each of a limited number of prospective locations lacks one or more desirable qualities. Where SEFs are not applied in the fan selection process, SEFs must be applied in the calculations of the results of field tests. Thus, for a field test, the fan static pressure is defined as: As indicated in the graph, reading publicstion uncertainty can be significant.
The following motor performance data was supplied by the motor manufacturer: This range is based on considerations of the conditions that are encountered in most field test situations.
AMCA Publication 203-90 (R2007), “Field Performance Measurement of Fan…
Therefore, recommendations regarding alternate test procedures and instrumentation for use for velocities less than fpm are not presented in this publication. The length of the duct should be a minimum of twice its diameter or equivalent diameter, and the entrance to the duct should be flared in order to reduce the entrance loss.
The calculations of fan flow rate are based on considerations of continuity of mass, and as such, it is assumed that no mass is added or removed from the gas stream between the traverse plane and the fan inlet.
Ps4 may be determined by averaging the static pressure measurements at each of four static pressure taps or by averaging the static pressure measurements made in a Pitot-static tube traverse of Plane 4.
Measure td2 in Plane 2. Obviously poorly tensioned and misaligned drives should be corrected before estimating brake horsepowers and drive losses.
The density at Planes 1 and 4: In rectangular ducts, a pressure tap should be installed near the center of each wall. Most of the instruments require frequent calibration, and some are not suited for use in high temperature, dirty, wet, corrosive, or explosive atmospheres.
AMCA Publication R – Free Download PDF
A temporary short duct is installed upstream of the silencer to establish Plane 3 in which more uniform pressures can be obtained. If it is possible to install suitable pressure taps, their use is preferred in the region of the fan outlet. If a Pitot-static tube is used, it should be positioned well publicatoon the duct in which Plane 4 is located, and not project into the upstream elbows. In situations such as this example, it is important to be certain that all pressure measurements are referred to the same atmospheric pressure.
This assumption may not be valid, and the calculated pressure loss values may be significantly inaccurate. In order to compare the test results to the quoted unit assembly curve drawn for operation at rpm and 0.
At this point, the static pressure is zero, and AMCA R the velocity pressure in still air is zero. This graph pubilcation the effect of expected resolution of velocity determinations.
A manometer with either vertical or inclined indicating column may be used to measure static pressure. Fan speed measurement was not obtained due to the closed duct arrangements on both sides of the fan. In addition, the density at Plane 2, the fan outlet, must be determined whenever the fan total pressure, the fan velocity pressure, or an SEF at the outlet side of the fan is required.