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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ComiXology Thousands of Digital Comics. Note that ef and eg vary with point of operation. Demonstrated accuracy is defined for the purposes of this standard as the accuracy of an instrument or the method established by testing of the instrument or the method against a primary or calibrated instrument azhrae method in accordance with the requirements of this standard.
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 findings from a total pressure analysis would be similar to those of a static pressure analysis.
Their derivation is as follows: When a star straightener is used: Pressure losses shall be calculated for measuring ducts and straighteners that are located between the fan and the plane of measurement.
Such pieces shall not contain any converging element that makes an angle with the duct axis greater than 7. Minimum M is determined by the requirements of Section 5. The test chamber is pressurized and the valve is closed. The range of airflow over which equilibrium cannot be established shall be recorded and reported.
The fan law equation for fan velocity pressure Pv follows from that for fan total pressure: An upstream pressure tap shall be located as shown in the figure for the appropriate setup. Standard air has a ratio of specific heats of 1. Hollow flexible tubing used to connect measurement devices to measurement locations should be of relatively large inside diameter. An examination of x and z will reveal that x is the ratio of the totalpressure rise to the absolute total pressure at the inlet, and ashhrae z is the ratio of the total-temperature rise to the absolute total temperature at the inlet.
Fan total pressure, fan static pressure, or ashre may be shown.
Groups approve laboratory methods for testing fans.
Traverse duct shall be round within 0. The resultant curve is shown 51-70 Figure F. Nevertheless, a pre-test analysis is recommended, as is a post-test analysis. Reverse flow verification test. The dimensions ‘b’ and zshrae are the width and height of a rectangular section of a duct. The requirements of dynamic similarity lead directly to the pressure relationships expressed by the fan laws.
Amazon Second Chance Pass it on, trade it in, give it a second life. The results of an on-site test may deviate from predicted values because of additional uncertainties in measurements such as poor approach conditions to measuring stations. The compressibility coefficient Asheae may be determined from: Therefore, it is the difference between static pressure at the fan outlet and total pressure at the fan inlet.
Instruments shall be set up, calibrated, and read by qualified personnel trained to minimize errors. They shall provide sufficient pressure at the desired airflow to overcome losses through the test setup.
ashrrae Wet-bulb and dry-bulb thermometers should be of the same type. These devices shall be free from slip and calibrated. A small dimension J may make it difficult to meet the criteria given in Annex A. The cross-section of the elliptical portion is one quarter of an ellipse, having the large axis Asnrae and the small axis 0.
The names of test personnel shall be listed with the data for which they are responsible.
amca 210 07 airflow nozzle
The sample analysis given in Annex F calculates the uncertainty in each of the fan performance variables, and in addition, combines certain ones into a characteristic uncertainty and others into an efficiency uncertainty.
A total pressure tube is sensitive only to the pressure in the immediate vicinity of the open end. Amazon Music Stream millions of songs. 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.
The total pressure or static pressure at a point may be sensed with a Pitotstatic tube of the proportions shown in Figure 1A and 1B.
Report and Results of Test 8. Air with a standard density of 1. The temperature that exists by virtue of the internal energy of the air.
However, AMCA International and ASHRAE do not guarantee, certify or assure the safety of performance of any products, components or systems tested, designed, installed or operated in accordance with this standard or that any tests conducted under this standard will be non-hazardous or free from risk.
Fan pressure and fan power shall be ashare as ordinates. 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 to a static pressure sensor, such as a static pressure tap or the static tap of a Pitot-static tube.
Cell sides shall be flat and straight. The pressure when the datum pressure is absolute zero.
The manufacturer of the manometer must supply the information for correction of the graduated scale due to temperature changes. The fan airflow rate Q at test conditions shall be obtained from the equation of continuity: Hg and readable to 34 Pa 0. Similarity and Fan Laws Informative. An airflow measurement method that utilizes a meter or traverse other than an airflow nozzle or Pitot traverse shall be acceptable under this standard if the uncertainty introduced by the method does not exceed that introduced by an appropriate flow nozzle or Pitot-static traverse method.
The Reynolds number Re based on the hydraulic diameter Dh in m ft shall be calculated from: The characteristic uncertainty can be defined with reference to the following diagram: