Fan Affinity Laws

Q ~ N, P ~ N^2, kW ~ N^3 across RPM, CFM, SP, and kW changes.

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Formula and source

Q2/Q1 = (N2/N1); H2/H1 = (N2/N1)²; P2/P1 = (N2/N1)³. Laws apply for geometrically similar fans / pumps at the same point of operation.

Hydraulic Institute / AMCA by name; classical pump and fan theory.

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