ASHE Certified Healthcare Constructor (CHC) Practice Exam

The formula to calculate cubic feet per minute (CFM) involves understanding how airflow is measured in relation to the volume of a space and the Air Changes per Hour (ACH). CFM indicates the volume of air moved in one minute and is crucial for determining ventilation adequacy in healthcare facilities.

In this case, the correct formula is derived from the relationship between ACH, the total volume of the room, and the time factor. Specifically, ACH represents the number of times the air within a given volume is replaced in one hour. To convert this into a per-minute measurement, the total volume of the room is divided by 60 (to convert hours into minutes).

Thus, when you multiply the ACH by the volume of the room and then divide by 60, you effectively convert the hourly airflow (as expressed by ACH) into a minute-based measurement, yielding the CFM. This formula is essential for ensuring that healthcare environments maintain proper air quality and circulation, which is particularly important for patient safety and infection control.

It's important to grasp this relationship for effective design and operation in healthcare facilities, where meeting ventilation standards is critical.