Subject: Why are radiator fan blades non-symmetrical?

There are two types, the electric and the belt driven. I refer to the 
latter. If you go to an auto parts store you will see that the 
propellers are not symetrical, in fact, one open angle which the air 
passes thru is larger than the other angles. However, the electric fan 
blades are symmetrical. It must have something to do with blowing air 
or sucking air, electric or belt driven, but doesn't seem to make 
sense. This is rare, except for mixing blades, which may have one 
blade with an open hole for better mixing, or alternative blades with 
an open hole.

Regards,

Bob

Re: Why are radiator fan blades non-symmetrical?