What happens to CFM if the drive sheave size is doubled?

Doubling the drive sheave size will result in a direct increase in the airflow measured in cubic feet per minute (CFM). The drive sheave is part of a pulley system that helps control the speed of a fan or blower. Specifically, if the drive sheave size is increased, the fan will rotate faster, which leads to an increase in air movement and subsequently, a higher CFM.

This relationship can be attributed to the physics of rotating systems where the diameter of the sheave influences the speed and torque of the connected components. When the drive sheave size is doubled, it effectively enhances the mechanical advantage, allowing the fan to push more air through the system. Therefore, while airflow characteristics can be affected by other factors such as system resistance, in this scenario, the doubling of the sheave size means that the airflow output, CFM, will increase in a proportional way.