Cooling fans are not necessarily better with higher air volume

Conclusion: The air volume of the cooling fan is not necessarily better, but needs to be adapted to the wind pressure, system resistance, and application scenario in order to achieve the best cooling effect.

1、 The correlation between air volume and heat dissipation effect

Airflow is indeed a key element for heat dissipation, but there is a marginal effect:
Basic principle: Within a certain range, the larger the air volume, the more heat is carried away per unit time, and the better the heat dissipation effect.
Physical formula: Heat dissipation power H ≈ air volume (Q) × temperature rise (Δ T) × specific heat of air (cp), where air volume directly determines the total amount of heat exchange.
Actual situation: When the air volume increases to a certain critical value, the improvement of heat dissipation effect will become slow and may even decrease (such as airflow disorder and increased energy consumption).

2、 Why does excessive airflow have the opposite effect?

1. The noise is growing explosively
Noise is proportional to the fifth power of rotational speed, while air volume is only proportional to the third power of rotational speed.
Example: When the fan speed is increased from 1500RPM to 3000RPM, the air volume increases by about 2.8 times, but the noise surges from 28dB to 48dB (energy increases by about 100 times).
2. Dual damage to energy consumption and lifespan
The power consumption is proportional to the third power of the rotational speed, and an increase in air volume means an increase in electricity expenses.
High speed will accelerate bearing wear and significantly shorten the service life of the fan.
3. Air flow efficiency actually decreases
Excessive air volume may cause turbulence in the airflow, forming vortices and reducing heat dissipation efficiency.
In a closed system, as wind resistance increases, the effective air volume may be less than 30% of the nominal value.

3、 The selection of a cooling fan is an art of balance, rather than simply believing that 'the larger the air volume, the better'.

Airflow is the foundation: ensuring sufficient airflow is a prerequisite for heat dissipation, but it is not the only measure.
Wind pressure is key: in environments with resistance, wind pressure determines whether the airflow can effectively function.
Best choice: Fans with air volume and pressure matching should be selected based on equipment characteristics, system resistance, and usage environment.