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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Also shown is a parabola with the vertex at the origin that intersects the fan curve and both of the boundaries. The fan law equation for fan velocity pressure Pv follows from that for fan total pressure: This will lead to non-reproducible results unless actual duct configuration is identified.
In the I-P system, pressures are expressed in manometric head pressure, such as inches of water or inches of mercury. A pre-test uncertainties analysis is not required for each test covered by this standard because it is recognized that most laboratory tests for rating are conducted in facilities where similar tests are repeatedly run. In addition, an allowance must be made for the mental averaging which is performed on fluctuating readings.
Any bi-stable performance points airflow rates at which two different pressure values can be measured shall be asshrae. If the volumetric airflow rate at the inlet Q1 is proportional to peripheral speed, the volumetric airflow rate at 51-70 outlet Q2 cannot be proportional to peripheral speed or vice versa except for the same degree of compression. Complete dynamic similarity requires that the ratios of all corresponding forces in the two fans be equal.
Groups approve laboratory methods for testing fans.
The equation for efficiency may be rearranged to give either: The pressure when the datum pressure is absolute zero. The ratio of equivalent length Le of a straightener to hydraulic diameter Dh shall be determined from the elemental thickness y and the equivalent diameter D using: A total pressure tube is sensitive only to the pressure in the immediate vicinity of the open end. Tubing Informative Large tubing should be used to help prevent blockage from dust, water, ice, etc.
Additional ductwork of any size including elbows may be used to connect between the chamber and the exit of the 10D minimum test duct.
If air is at rest, its total pressure will equal the static pressure. When pressure response times are long, inspect for possible blockage.
At the time of publication, the editions indicated were valid. When a chamber piezometer or total pressure tube asrhae used for pressure measurement, the average static pressure Ps7 shall be the measured value Ps7r and the average total pressure Pt8 shall be the measured value Pt8r.
See Figure 15, Note 5. It also applies to Figure 15 in Plane 8, in which case, the mean velocity in Plane 6 nozzle outlet is called the jet velocity.
The correct procedure is to subtract the losses for the first condition, make fan law projections of power input for the corrected first condition to the second condition, and then add the bearing and drive losses for the second condition. Temperature td2 may be considered equal to td5.
On the inlet duct setup, ts1 is equal to td3 and 51-0 may be considered equal to Pt3 for fan air density calculations. The process during compression may be plotted on a chart of absolute total pressure P versus flow rate Q. For incompressible flow, the compressibility coefficient is unity and power input is proportional to airflow rate times pressure divided by efficiency. Amazon Renewed Refurbished products with a warranty. The fan laws should not be employed if asrhae condition is suspected.
The net effect with respect to speed is second power. See Figures 13 or 14, Note 5, or Figure 15, Note 6, for requirements. The nozzle throat dimension L shall be either 0. The static pressure at a point shall be measured on an indicator such as a manometer with one leg connected to atmosphere and the other leg connected ashrse a static pressure sensor, such as a static ashrar tap or the static tap of a Pitot-static tube.
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Purpose and Scope This standard establishes uniform test methods for a laboratory test of a fan or other air moving device to determine its aerodynamic performance in terms of airflow rate, pressure developed, power consumption, air density, speed of rotation, and efficiency for rating or guarantee purposes. When the fan discharges through an outlet duct without a measurement plane either to the atmosphere or into an outlet chamber, the pressure loss of the duct shall be considered zero and calculations shall be made according to either Section 7.
The form of the airflow straightener shall be as specified in Figure 6A or 6B. 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.
Additional ductwork of any size including elbows may be used to connect between the chamber and the exit of the SI units are based on the fundamental values of the International Bureau of Weights and 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.
A wet-bulb thermometer shall have an air velocity over the water-moistened wick-covered bulb of 3. Auxiliary fans may be used to control the point of test fan operation. Variable supply system may be an auxiliary fan or throttling device. Uncertainties Analysis  Informative F. If this alternate arrangement is used, and the calculated plane 8 velocity is greater than fpm, then the calculated plane 8 velocity pressure shall be added to the measured static pressure.
amca 210 07 airflow nozzle
This is generally acceptable because fans are not adhrae rated at the low pressure or low flow portions of their characteristic curves. Dotted lines on inlet indicate an inlet bell which may be used to approach more nearly free delivery.
The axes of the fan opening and duct shall coincide.
For this test, at least twelve 12 approximately equally spaced measurement points are located in a plane 0. The static orifices may not ashras 1 mm 0. The nozzle discharge coefficient C shall be calculated from: View shipping rates and policies Average Customer Review: The torque measured on any instrument will fluctuate with time.
Groups approve laboratory methods for testing fans.
A barometer reading shall be corrected for any difference in mercury density from standard or for any change in the length of the graduated scale due to temperature. It is controlled during a test by adjusting the position of a ashraae device, by changing flow nozzles or auxiliary fan characteristics, or by any combination of these.
When the mean of these readings is greater than Pa 4 in. The energy factor E may be determined by measuring velocity pressures Pvr upstream of the nozzle at standard traverse stations and calculating: