Message text written by INTERNET:ebk@buffnet.net
> My question is: if Bill G. 'inverts' the fan wouldn't the air move
in
the wrong direction. I'm not clear on what is ment by 'invert the fan'?
<
The answer is no. When you turn the fan blade around and put it on the
same shaft that is turning the same direction the pitch of the blade is
still in the same direction. However, most fan blades are optimised for
turning in one particular direction and reversing the fan makes it go
backwards and the angle of attack is all wrong and you will get
dramatically less air flow. I have verified this on a puller fan from a VW
that I installed as a pusher in my TR6. Since the motor had to be reversed
I found the air flow to be disappointing. I reversed the blades and the
performance was back.
Speaking of electric fans, I once saw an installation where the electric
fan was turning the wrong way and pushing air forward. I reversed the
wires and fixed the error. (BTW radiators don't care which direction the
air flows but in a moving application forcing air in the opposite direction
of the flow induced by vehicle movement is counterproductive in certain
situations. Most stationary applications push air away from the engine
(and hopefully out of the building))
Dave
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