CFM stands for Cubic Feet Per Minute. It’s a term that you’ll hear thrown around when someone is discussing airflow. It’s used to measure the volume of your airflow. This means the CFM itself is determined by how many cubic feet of air pass by a stationary point in one minute. You’ll notice that smaller homes have a lower CFM. This is because the space is smaller meaning that it circulates less air and has a lower CFM as a result.