Engineering Section

ENGINEERING AND APPLICATION DATA
The Performance Date Are Based On Conducted In ETL Testing Laboratories N.Y. U.S.A (Recognized Testing Laboratory For ADC). Testing of The Devices Would be Conducted In Accordance With Followings Test code And Standard.
風口性能數據是美國ETL Testing Laboratories (一間美國ADC確認之實驗室)提供之試驗報告編寫而成，而測試之型式及規格是根據下列各項標準而進行。
Air Diffusion Council Test Code for Grilles, Registers and Diffusers ADC 1062: GRD-84.
ISO Standard 5219, "Air Distribution and Air Diffusion - Laboratory
Aerodynamic Testing and Rating of Air Terminal Devices".
ISO Standard 3741, "Determination of Sound Power Levels of Noise Sources - Precision Methods for Broad-Band Sources in Reverberation Rooms".
ISO Standard 5135, "Determination of Sound Power Levels of Noise from Air Terminal Devices, High/ Low Velocity/ Pressure Assemblies, Dampers and Valves by Measurement in a Reverberation Room".
ASHRAE Standard 70-1991, "Method of Teating for Rating the Performance of Air Outlets and Inlets".

TEST METHOD
The diffusers were tested in accordance with the Air Diffusion Council Test Code for Grilles, Registers and Diffusers No. ADC 1062: GRD-84. The diffusers were tested in our 470M3 reverberation room. Quiet test air was provided by a variable volume air supply. Air volume was measured by the use of a calibrated orifice metering station while the static pressure was measured employing a Dwyer Model 166-12, 1/8" Diameter Standard Pitot Tube and read on a Dwyer Manometer Model 424-5.

Acoustical data was obtained employing a Bruel and Kjaer Digital Frequency Analyzer Type 2131 and analyzed on a CompuAdd 286 Computer and Epson LQ-850 printer. The reference sound source used for this test was a calibrated ILG Fan Serial No. 17-05-066A. The octave band sound power levels were plotted on a graph of Noise Criteria Curves which is in the ADC Test Code. These curves are reprinted with permission from ASHRAE Handbook and Product Directory, 1976.

* Sound power level data has reached ambient levels in the test room or is determined by instrument limitations. Actual levels are less than or equal to the levels indicated.
** NC values were determined by subtracting room absorption of 10 dB from the sound power level data.

TEST OUTLINE
All equipment will be installed and tested as specified in ISO 5219. Representative sized of a product series will be tested. Performance data for non-tested sizes will be interpolated or extrapolated from generated test data provided that the test data show predictable extension from ernpirically established parameters of a geometric or modular relationship.

For the testing of the air terminals for pressure ,air velocity, throw and drop, the air terminals will be mounted in a test duct with a cross-sectional area equal to the nominal size of the device or to the duct dimensions normally recommended by the manufacturer. The test installation will be constructed as shown in Figure 1 of the standard. This test installation is in a test room which meets the requirements of Section 4 of the standard, namely, the room should have a height of not less than 2.8 meters, a width from 1.5 to 2.2 (times the height) and a length of 7.5 meters. The room is constructed so that all surfaces are normal at the corners and any surface over which the supply air path flows shall be smooth and flat. Air is exhausted from the test room at locations away from the supply air path and out of the planes of measurement.

For the testing of the air terminal for sound, ETL will use the same terminal type set up as for the previous tests, but the terminal will be set up in our 470 cubic meter reverberation room in accordance with Figure 1 of ISO Standard 5135 and sound power level measurements will be conducted in accordance with ISO Standard 3741 and ISO Standard 3742.

TERMINOLOGY

Area, Outlet (AK) : The area of an outlet utilized by the air stream at the point of the outlet velocity, VK, (See Velocity, Outlet) as measured with an appropriate meter. CFM = AK x VK . The point of measurement and type of meter must be defined to accurately determine CFM.
Noise Criteria (NC) An outlet sound rating in pressure level at a given condition of operation, based on established criteria and a specific room acoustic absorption value. Catalog NC Ratings are based on sound power level (Lw) re 10 -12 watts minus an 10 db room attenuation in all octave bands.
Occupied Zone That interior area of a conditioned space which extends to within 6 inches of all room walls and to a height of 6 feet above the floor.
Pressure, Static (PS) The pressure in inches of H2O that exists in the diffuser or grille collar area at a given air volume with or without specific designated accessories.
Pressure, Total (PT) The sum of the static pressure (PS) and the velocity pressure (PV) that exists in the diffuser or collar for a given air volume.
Pressure, Velocity (PV) The pressure in inches of H2O equated to a velocity that exists for a given air volume in the difuser or grille collar area.
Temperature Differential (∆T) The difference between primary supply and room air temperatures.
Throw (T) The distance in feet from an outlet or designated location to a point where the motion of the air stream is reduced to a given Terminal Velocity.
Velocity, Outlet (VK) The measured velocity at a stated point with a specified meter. The rate outlet velocity is typicallv an average of several prescribed velocity measurements. CfM = AK x VK (See Area, Outlet).
Velocity, Residual (VR) The average sustained velocity within the confines of the occupied zone, generally ranging from 20 to 70 FPM.
Velocity, Terminal (VT) The velocity in FPM of the air stream at the end of the Throw (T) from the diffuser or a designated point. Values of 50, 75, 100, 150 and 200 FPM are in common use.


RECOMMENDED NC CRITERIA
NC Curve Communication Environment Typical Occupancy
Below NC 25 Extremely quiet environment, suppressed speech is quiet audible, suitable for acute pickup of all sounds. Broadcasting studios, concert halls, music rooms.
NC 30 Very quiet office, suitable for large conferences; telephone use satisfactory. Residences, theaters, libraries, executive offices, directors' rooms.
NC 35 Quiet office; satisfactory for conference at a 15 ft. table; normal voice 10-30 ft; telephone use satisfactory. Private offices, schools, hotel rooms, court-rooms, churches, hospital rooms.
NC 40 Satisfactory for conferences at a 6-8 ft. table; normal voice 6-12 ft.; telephone use satisfactory. General offices, labs, dining rooms.
NC 45 Satisfactory for conferences at a 4-5 ft. table; normal voice 3-6 ft.; raised voice 6-12 ft.; telephone use occasionally difficult. Retail stores, cafeterias, lobby areas, large drafting & engineering offices, reception areas.
Above NC 50 Unsatisfactory for conferences of more than two or three persons; normal voice 1-2 ft.; raised voice 3-6ft.; telephone use slightly difficult. IBM rooms, stenographic pools print machine rooms, process areas.