Many of you guys around here seem to have technical expertise outside of the field of firearms so here is a question for ya...

My folks have a ceiling fan in a small room with a low ceiling.  The fan can spin on high power and for some reason it has no effect.  There is no cool breeze or anything felt from the fan.  Why is this???  Could the blades be too long or too short???  Could they be installed on the fan incorrectly??? Could they be spinning in the wrong direction???  Its a weird question, but I would like to know why physics seem to be on the fritz!
Thanks

That would be my guess. Maybe they reversed the polarity and the fan is blowing the air up instead of down. That's why you only feel it when its on HI. When its on high the air is bouncing off he ceiling enough to feel the breeze, on LO its only stirring the air up there.

But then again I could just be blowing hot air.

Check to see if the blades are upside down, very easy mistake. Also it helps if there a window open.

SGB hit the nail on the head for proper use

You cant hook up an A/C moeter backwards.  For reasons too complicated to explain here, the motor will run the same direction no matter how it's hooked up.  There is a rotational direction switch, usually a slide switch on the switch body.  The only other possibility is that the blades are installed incorrectly.

Small room & a low ceiling ? If the blades are really close to the ceiling, they may be cavitating, there may just not be free space enough for them to work properly.
Hold a big ass stinky cigar in various places near the fan & see what the air is doing.

No one mentioned one other option.
An inexpensive fan is sometimes very inefficiently designed. Just bought a house with one of those, it was a little noisy and did not push air at all. Also have low ceilings which does create a problem for the fan. Replaced it with a better unit and love it.
The bad ones have a very shallow blade pitch which allow them to cut through the air without moving much of it. Good luck.