The airflow direction of a heatsink fan is usually designed for optimal heat dissipation. For downdraft or downdraft style coolers, the fan is mounted in the direction of the heatsink to ensure that the CPU temperature is maintained at a suitable range by drawing in cool air and removing heat.
In a tower cooler, on the other hand, the fan is blown in towards the memory, which ensures that hot air is expelled directly from the case, preventing it from circulating internally and causing the CPU to overheat. The fan's operation relies on electrical power, which is converted from electromagnetic energy to mechanical energy, ultimately creating the kinetic energy that drives the air flow.
When choosing a cooler, there are a few key factors to consider: first, the more powerful the fan, the stronger the wind, and the better the cooling performance. Second, the speed is also an important factor. Higher speeds provide more airflow, but too high a speed can bring noise and wear problems. Heat sink materials, such as copper, are commonly used for mid- to high-grade radiators because of their good heat dissipation performance. In addition, the noise and air displacement of a fan are important measures of its performance, and a number of factors, including blade design and speed, affect these properties.
Overall, the airflow and performance of a radiator fan is chosen to improve cooling efficiency and stability, while also needing to balance various factors to achieve the best possible experience.