What effect does increasing the speed of a fan generally have on airflow?

Increasing the speed of a fan generally results in an increase in airflow. This is because fans operate by creating a difference in pressure that draws air in and expels it out. When the fan speed is ramped up, the blades move faster, which increases the velocity at which air is moved through the system.

As the fan speed increases, the kinetic energy imparted to the air also rises, leading to a greater volume of air being circulated. This principle applies in various HVAC systems, where fan speed can be adjusted to improve ventilation and meet the heating or cooling demands of a space.

In contrast, decreasing the speed of the fan would reduce the amount of air moved, and maintaining the same speed keeps airflow constant. Altering the air temperature is not a direct consequence of changing fan speed, as it primarily affects air movement rather than temperature. Therefore, increasing the fan speed directly correlates with increased airflow, making it the correct choice.