Cubic Feet Per Minute
Cubic feet per minute (CFM) is an often confusing term because it has no single definition that applies to all instances. In the most basic sense, CFM means cubic feet per minute. Unfortunately, gases are compressible, which means that a figure in cubic feet per minute cannot be compared with another figure when it comes the mass of the gas. To further confuse the issue, a centrifugal fan is a constant CFM device or a constant volume device. This means that, provided the fan speed remains constant, a centrifugal fan will pump a constant volume of air. This is not the same as pumping a constant mass of air. Again, the fan will pump the same volume, though not mass, at any other air density. This means that the air velocity in a system is the same even though mass flow rate through the fan is not.
Read more about this topic: Standard Cubic Feet Per Minute
Famous quotes containing the words cubic, feet and/or minute:
“One of the great natural phenomena is the way in which a tube of toothpaste suddenly empties itself when it hears that you are planning a trip, so that when you come to pack it is just a twisted shell of its former self, with not even a cubic millimeter left to be squeezed out.”
—Robert Benchley (1889–1945)
“Henri IV’s feet and armpits enjoyed an international reputation.”
—Aldous Huxley (1894–1963)
“One writes of scars healed, a loose parallel to the pathology of the skin, but there is no such thing in the life of an individual. There are open wounds, shrunk sometimes to the size of a pin-prick but wounds still. The marks of suffering are more comparable to the loss of a finger, or the sight of an eye. We may not miss them, either, for one minute in a year, but if we should there is nothing to be done about it.”
—F. Scott Fitzgerald (1896–1940)