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Posted by: Ynot on 2007-09-05, 07:33:36
The outer diameter of the fan must be much greater than the inner diameter. The number of blades must be more than necessary to agitate the desired volume. The blades will usually be more than an hour long. The revolutions per minute will be very few, unless it is a Central American fan in which case the revolutions will be more. The fan must be taller than it's diameter, unless it is lying on it's side in which case it should be taller than its length, but centrifugal fans are almost always shorter than soccer fans. The formula for calculating our fan is Volume flow rate x Increase in static pressure x Fan Efficiency = Fan power So, in addition to being given the air flow in cubic meters per hour, we also need to be given the desired static pressure rise, then we can start to make our design maybe. |
