The main parameters, characteristic to a fan, are four in number
Speed of rotation (Rpm)
The capacity is the quantity of fluid moved by the fan, in volume, within a unit of time, and it is usually expressed in m3/h, m3/min., m3/sec.
The total pressure (pt) is the sum of the static pressure (pst), i.e. the energy required to withstand opposite frictions from the system, and the dynamic pressure (Pd) or kinetic energy imparted to the moving fluid (pt = pst + PD). The dynamic pressure depends on both fluid speed (v) and specific gravity (y).
The efficiency is the ratio between the energy yielded by the fan and the energy input to the fan driving motor.
- Speed of Rotation
The speed of rotation is the number of revolutions the fan impeller has to run in order to meet the performance requirements.