The airflow generated by a fan is primarily dependent on power, which is a function of both rotational speed and torque. The relationship can be expressed through the equation Power = (Rotation Speed) * (Torque). Affinity laws can be used to understand how changes in speed affect flowrate, head, and power. While the flowrate is influenced by the speed, the design of the fan also plays a crucial role in determining torque. Ultimately, for a fixed flowrate, the efficiency of the fluid-moving device and prime mover assembly dictates the power required, regardless of the speed of the fan.