Noise generated by Fans - Blade Pass Frequency (BPF)
Calculate the Blade Pass Frequency (BPF) noise generated by a fan based on rotation velocity and number of blades. The BPF varies with the number of blades and rotation speed of the wheel.
Blade Pass Frequency (BPF) Calculator
The Blade Pass Frequency noise generated by a fan can be very intense and varies with the number of blades and the rotation velocity.
Formula
BPF = n · t / 60
Where:
- BPF = Blade Pass Frequency (Hz)
- n = Rotation velocity (rpm)
- t = Number of blades
Key Points
- The energy in the sound may be very high and annoying for the surroundings, especially for fans with few blades
- The Blade Pass Frequency may not be visible in common fan charts
- Fan noise in general is documented in octave bands