I wonder if fans with (not a power of 2) blades could also generate surprising tonal (i.e., not transient) frequencies. I could imagine this logic also applyin

I wonder if fans with (not a power of 2) blades could also generate surprising tonal (i.e., not transient) frequencies. I could imagine this logic also applying to other pumps in the house: AC pumps, baseboard heat circulators, sump pumps, etc.