Other factors may have an equal or greater effect on fan performance.
This is generally acceptable because fans are not usually rated at the low pressure or low flow portions of their characteristic curves. The coefficient of friction f shall be determined from : A leakage test should be performed prior to initial use and periodically thereafter, with corrective action taken if necessary. The procedure is to pressurize or evacuate the test chamber and use a flow meter to establish the leakage flow rate. Each pressure tap shall conform to the requirements in Section 4. The minimum distance between the centers of any two nozzles in simultaneous use shall be three times the throat diameter of the larger nozzle. During a laboratory test, the air density and rotational speed may vary slightly from one determination point to another. The description of the test fan shall be recorded. The specification permitting an uncertainty based on the maximum observed test reading during the test leads to combined relative uncertainties in both fan pressure and fan airflow rate that are higher at low values of the fan pressure or fan airflow rate than at high values of those test results.Ī torque measurement device shall have a static calibration and may have a running calibration through its range of use. If a portion of the internal energy is converted into kinetic energy, the static temperature is decreased accordingly. and Air-Conditioning Engineers (ASHRAE) approved ANSI/AMCA Standard ANSI/ASHRAE Standard, Laboratory Methods of Testing Fans for. Standard - Laboratory Methods of Testing Fans for Aerodynamic Performance Rating (ANSI/AMCA Standard ) (ANSI/ASHRAE Approved). Standard and ANSI/ASHRAE Standard 51, except as modified by Units shall be tested in accordance with ANSI/AMCA Standard /ANSI/ASHRAE.