Scag Giant-Vac - CFM Performance Ratings.
When shopping for a blower, vacuum or loader, you will undoubtedly run into the acronym CFM (Cubic Feet per Minute). CFM is the amount of air that is being moved. It is a measurement of volume, that is how many cubic feet of air is being moved for every minute of operation. More CFM is a good thing and means more air to push the dirt, leaves or debris you are trying to move.
Here's how we collected the published CFM data on Scag Giant-Vac products. An accepted engineering method of collecting CFM data is to take a reading at a distance of approximately 10X the diameter of the output tube. Example: if the output tube is 6" in diameter, we would extend the tube about 60" and take readings at the end of that tube. This is a good method as it gives the fast moving, turbulent air some time to settle down for more consistent, real-world, non-exaggerated readings.
Depending on the diameter of the tube, up to 24 readings are taken in different locations across the output of the tube (reference the orange dots in the illustration above as an example). As you might expect, the numbers can vary depending on where in the tube you take the reading, so we take an average of those various readings and that is the CFM rating we publish.
To be certain this was a fair method when comparing our numbers against the competition, we tested their equipment using the same method. We achieved the same CFM numbers they publish online and/or in their brochures (for those that publish their CFM ratings).