What mathematical operation is used to adjust fan RPM based on airflow changes?

When adjusting fan RPM (revolutions per minute) based on changes in airflow, multiplication is commonly used to determine the relationship between airflow and the speed of the fan. This operation is significant because airflow (often measured in cubic feet per minute or CFM) is proportional to the RPM of the fan; as you increase the RPM, you expect an increase in airflow. Hence, when you need to find the new RPM for a desired airflow level, you typically multiply the original RPM by a factor that represents the change in airflow requirements.

For example, if the airflow needs to be doubled, you would multiply the existing RPM by two. This approach provides a straightforward way to scale the RPM to meet the new demands of the system. Utilizing multiplication in this context helps HVAC professionals calculate necessary adjustments quickly and accurately, ensuring both efficiency and performance in heating, ventilation, and air conditioning systems.