TECHNICAL SUPPORT

airflow_calcthermal_calc
   
   

1.0  FAN CHARACTERISTICS ARE MEASURED AS FOLLOWS:

1.1 Measuring the Air Volume and Static Pressure

 

 

     

 

The equation:

*Air volume Q=60 ×C ×× [m/min]

C : Coefficient of nozzle air volume

D : Diameter of nozzle [m]

r : Air density (1.293 ××) [Kg/m]

t : Temperature[]

P : Air pressure [mmHg]

Pn : Differential pressure of air volume mmAq=[Kg/m]

g : 9.8m/sec

Static pressure : ps=ps [mmAq]

Maximum static pressure:

As shown in the above figure, when closing the nozzle, the pressure in the "A" chamber will reach its maximum. The differential pressure, (Ps) between the air pressure and the pressure in the "A" chamber is the maximum static pressure.

Maximum air volume:

When opening the nozzle and absorbing the air using the auxiliary blower to make the static pressure equal to zero (ps=0), the differential pressure (PN) between the "A" chamber and the "B" chamber will reach the maximum. The air volume obtained by applying the differential pressure (PN) to the above equation is called the maximum air volume.

CONVERSION CHART

STATIC PRESSURE

1 mmHO = 0.0394 inch HO
1 mmHO = 9.8 Pa
1 mmHO = 25.4 mm HO
1 Pa = 0.102 mm HO
1 inch HO = 249 Pa

AIR FLOW

1 m/min = 35.31 ft/min(CFM)
1 CFM = 0.0283 m/min
1 m/min = 16.67 l/sec
1 CFM = 0.472 l/sec
1 l/sec = 0.06 m/min

 

1.2 Performance Point :

The Performance Point is the point at which the system impedance curve and the air static pressure curve intersect.

The Performance Point equals the air volume (throughput) of the fan when the fan is operating.

The Performance Point Curve is as follows::

 

 

1.3 Determination of Air Volume :

The following formula should be used to calculate Air Volume:

Q=40W/(T2-T1)

Where :

Q : Required air volume [M/MIN]

 

W : Amount of heat generation within cabin

 

T1 : Temperature of intake air to cabin

 

T2 : Temperature of exhausted air from cabin

1.4 Noise Level Testing :

Acoustic noise is measured in a semianechoic chamber by means of a B&K precision integrating sound level meter with a background noise level below 20dBA. The fan is operating in non-resistant air with a microphone at a distance of one meter from the fan intake.

 

 

Sound pressure level (SPL) which is environmentally dependent and sound power level (PWL) are defined as

SPL = 20 log10 P/Pref

and PWL = 10 log10 W/Wref

where P = Pressure

Pref = A reference pressure

W = Acoustic power of the source

Wref = An acoustic reference power

Fan noise data is usually plotted as Sound Power Level against the octave frequency bands.

The measurement standard is according to : CNS 8753

 

 

2.0 CHARACTERISTICS' DEFINITION TOP OF PAGE

2.1 Rated current :

Rated current is measured after five minutes of continuous propeller rotation at a rated voltage.

2.2 Rated speed :

Rated speed is measured after five minutes of continuous propeller rotation at a rated voltage.

2.3 Start Voltage :

The voltage required to start the fan after it has been switched on.

2.4 Input power :

Input power is measured after 5 minutes of continuous rotation at a rated voltage.

2.5 Locked current :

Locked current is measured within one minute of rotor lock-up (after 5 minutes of continuous rotation at a rated voltage in clean air).

2.6 Air volume & static pressure :

The air volume data and static pressure is determined in accordance with the AMCA standard or the DIN 24163 specification in a double chamber test with intake-side measurement.

 

 

3.0 MECHANICAL INSPECTION TOP OF PAGE

3.1 Rotation direction :

Clockwise from the front face of the fan a Clear ""(arrow mark) shall be found on the body of housing.

3.2 Safety design:

All fans are engineered to prevent damage to the winding and all electrical components during a locked rotor condition. Restart is automatic when the obstruction is removed.

3.3 Locked rotor protection :

No damage was found during a 72-hour test in which the rotor was locked on an operating fan. The fan restarted automatically as soon as the obstruction was removed.

3.4 Polarity protection :

Up to normal polarity, no damage was found during a reverse connection test at the rated voltage.

3.5 Vibration Test :

Vibration tests are conducted in accordance with JIS C0040, Amplitude 1.5 mm,
Frequency 10~55Hz, 0.5 hour in 3 axes (X,Y,Z)

3.6 Shock Test : JIS C0040 Acceleration of Gravity

60G Time = 6 msec. in 3 directions each: X,Y,Z

 

 

4.0 ELECTRICAL INSPECTION TOP OF PAGE

4.1 Insulation resistance :

More than 10,000,000 ohm between the housing and the positive end of the lead wire (red wire) at 250 V.D.C.

4.2 Dielectric strength :

No damage detected at 500 V.D.C 60 sec. or 600 V.A.C. 2 sec., measured
with a 5mA trip current between the housing and the positive end of the
lead wire.

4.3 Life expectancy :

The expected average life for a fan not designated as an Extended Life fan running at the rated voltage and in continuous operation at an ambient temperature of 25ºc and a humidity level of 65% is 50,000 hours. If any of the conditions listed below are met or exceeded, premature failure will occur.

Item

Level of Determination

Current

More than 15% of initial value

R P M

More than 15% of initial value

Noise

5dB A in excess of initial value

Starting Voltage

More than 10% of initial value

If any items above exceed the levels of determination failure will occur.

4.4 Insulation Class :

A Class

 

 

5.0 ENVIRONMENT TOP OF PAGE

5.1 Operating temperature :

-10 ~ +70 (normal humidity)

5.2 Storage temperature :

Satisfactory performace standards after 500 hours of storage at -40~70(normal humidity)with 24 hours recovery period at room temperature.