9G1248H4021 SANYO DENKI - SANACE FANS, 9G1248H4021 Datasheet - Page 7

• Manufacturer Part Number: 9G1248H4021
• Description: AXIAL FAN, 120MM, 48VDC, 100mA
• Manufacturer: SANYO DENKI - SANACE FANS

Specifications of 9G1248H4021

• External Height: 120mm
• External Width: 120mm
• External Depth: 25mm
• Current Type: DC
• Supply Voltage: 48VDC
• Flow Rate: 88CFM
• Noise Rating: 40dBA
• Power Connection Type: Lead Wires
• Bearing Type: Ball
• Flow Rate - Imperial: 88CFM
• Rohs Compliant: Yes
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant

Guideline in selecting a fan
The following example is a guideline regarding how to select an appropriate fan for cooling your system
1. Determining of your system specifications
Determine the temperature rise inside your system and obtain the
total heating value inside your system on the basis of its inputs
and outputs.
2. Calculating the Required Air flow for Cooling
After the equipment specifications and conditions of your system have been determined, calculate required air flow to meet the con-
ditions.
(Note that the formula shown below only applies when the heat radiation is performed only by cooling air from the fan.)
3. Selecting the Fan
After the motion air flow has been calculated, select an appropriate fan motor based on the value.
The motion air flow when the fan motor is actually mounted in your system can be obtained using the air flow-static pressure charac-
teristics curve and system impedance.
However, the system impedance cannot be measured without a measuring equipment, so fan with 1.5 to 2 times higher air flow than
the actual Max air flow should be selected (operating air flow is one-third to two-thirds of maximum air flow).
Next, In case that you select a fan having an air flow of 0.5
(m
your system.
For example, If you need a fan of 60mm square, 25mm thickness
and 12V, you should select is 109R0612H402 (maximum air flow
= 0.53m
4. Confirming the Selected Fan
Calculate the temperature rise inside your sysetem when your
sysetem having 100 (W) of total heating value is forcefully
cooled down by a 109R0612H402 fan.
From the above, the temperature rise inside your system is calculated as 14.2 （K） .
Since the value obtained from the above equation is only a rough target, final fan selection should be based on your actual installa-
tion test.
How to select an appropriate fan
Example
Example
Q': Motion air flow (m
Example
Q: Maximum air flow（m
Example
△T=V/20Q’=100（W）/20×0.353（m
3
and conditions
/min.) or more and a appropriate size for the space inside
Q’=Q×2/3=0.53×2/3
△T : Inside temperature rise（K）=15（K）
V : Total heating value of your system（W）=100（W）
3
/min.).
Q’=
Q’=Q×2/3
Q=Q’×3/2=0.33×3/2
20△T
V
=
≒
3
20×15（K）
/min.)
100（W）
0.353（m
3
/min.）
≒
0.5（m
3
/min）
≒
0.33（m
3
/min）
3
/min）
≒
3
/min）
14.2（K）
Static pressure
Pressure loss
V
Characteristics of air flow versus static pressure
and those of pressure losses of equipment
Heat source
Operating air flow
T
℃
System
Air flow
System impedance
Fan
Q'
5