Calculation of air volume for variable-frequency fans
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There is an inverter-driven fan here, and I want to know the air volume it generates at different frequencies; theoretical values are sufficient. I’m not sure if this calculation method is appropriate. For an inverter motor, the speed is given by n=60*frequency/pair of poles, and using this formula, the speed at different frequencies can be determined； Furthermore, since the fan flow rate is proportional to its speed, that is, Q1/Q2 = n1/n2, where Q represents the flow rate and n represents the speed. In this way, the air volume of the fan at different frequencies can be determined. I hope to receive your guidance
Ratio of frequencies = Ratio of air volume; Cube root of ratio of shaft power = Ratio of air volume
I suggest you take a look at the manufacturer’s information and you’ll understand
Reply 1# metaled: The principle is correct. But note that it is suitable at the same damper opening.
The actual situation is not like that; it is also related to system resistance