Clean fan... Significantly more effective?

[carreauchompeur]

Just pondering questions of science really.

I have a huge floor standing fan in my house. I'd noticed today that the blades were covered in dust, and that the leading edges had picked up lots of airborne cat hair so decided to give it a clean for cosmetic reasons.

It's now WAAAY more effective and a bit quieter. The latter I'd put down to smoother air flow but the former? I'm genuinely surprised. The surface area and power are the same....

[J4CKO]

Hmm, thought this was going to deliver something more interesting, but yes, less drag will allow the fan to turn more efficiently and possible faster and quieter.