Why can't the selection of fans be based solely on size and air volume?
Misconception 1: The thicker the fan, the better the heat dissipation?
Many engineers believe:
The 38mm thick fan is definitely better than the 25mm one, and the 25mm one is definitely better than the 10mm one.
However, this understanding is not entirely correct.
The thickness of the fan is just one of the structural parameters.
The actual heat dissipation capacity is also affected by:
And other factors have an impact.
For example:
Different thicknesses do not have absolute superiority or inferiority.
The key point is: Does it match the equipment requirements?
This is a common misconception in many fan selection scenarios.
In the product specification document:
"Maximum air volume"
Usually it is:
It was obtained through testing under static pressure conditions. That is to say:
There is no resistance either in front of or behind the fan.
But in the actual equipment:
Air needs to pass through:
All of them will cause resistance.
Therefore:
The actual output air volume of the fan will decrease.
For a simple example:
Two fans: Fan A has a maximum airflow of 30 CFM, but its static pressure capacity is low. Fan B has a maximum airflow of 25 CFM, but its static pressure capacity is high.
If the internal resistance of the equipment is high, the following situation may occur:
Fan A: 30 CFM → In fact, it only reaches 10 CFM
Fan B: 25 CFM → Actually, it achieves 18 CFM
Final result:
Fan B has a better cooling effect.
When upgrading many devices, one may encounter situations like: 60×60×25mm replacing 60×60×10mm.
Engineers often ask:
Reason:
The wind resistance of the equipment varies. The final operating state of the fan depends on:
Fan performance curve + System impedance curve.
The fan performance curve is also known as:
P-Q curve
Where:
P: Pressure (static pressure)
Q: Quantity (Air Volume)
It indicates: Under different pressure conditions, how much air volume can the fan output?
Simple understanding: The greater the wind resistance: The actual air volume is the lower.
On many parameter tables:
Maximum air volume: It is not the actual operating condition of the equipment.
What really needs attention:
Work points are as follows:
Engineering selection:
Attention should be paid to:
Rather than merely comparing the maximum air volume.
A certain medical testing equipment:
Original design:
60×60×25mm fan.
Due to the structural upgrade:
The thickness of the equipment needs to be reduced.
The engineer considered:
60×60×10mm ultra-thin fan.
Many people's initial reaction:
"10mm is so thin. It's definitely not as good as 25mm."
But it needs to be tested in practice.
If the equipment:
A 60×60×10mm size is definitely capable of meeting the requirements.
But if:
Then it might be necessary to: 25mm or 38mm option.
As industrial equipment continues to evolve:
The equipment is moving towards:
For example:
Focus: Low noise; Long lifespan; Stable operation.
Energy storage cabinet; Charging pile; Inverter.
Focus:
High load heat dissipation; Dust-proof and waterproof; Long-term operation.
Focus:
High wind pressure; High reliability; 7×24-hour operation.
In conclusion, the selection of industrial equipment fans is a systematic process that requires comprehensive consideration of multiple parameters such as airflow, static pressure, system impedance characteristics, installation space constraints, environmental conditions (such as temperature, humidity, dust grade), and equipment reliability requirements. The size and performance parameters of the fan are not isolated indicators but are jointly determined by the overall heat dissipation requirements of the equipment and the characteristics of the airflow path. Only by conducting quantitative matching analysis based on the intersection point of the P-Q performance curve and the system impedance curve (i.e., the actual working point), can the optimal balance be achieved among heat dissipation efficiency, noise level, energy efficiency ratio, and service life. Shenzhen Fuqingda Electronic Technology Co., Ltd. has been deeply engaged in the field of heat dissipation technology for over twenty years and possesses a full-chain service capability from thermal simulation modeling, fan customization design to overall machine heat dissipation verification. It can provide customers with professional and verifiable customized heat dissipation solutions. If you have any technical requirements in industrial fan selection or system-level thermal management, please feel free to inquire.