The room is 22' x 18'. Over the 18' width the ceiling height sies from 12' tp 18'.
Where should I position the fan along the 18'width and at what height? Please include your reasoning behind your decision.

merron:
Could you focus your question a bit...
I assume this is in a dwelling? What room, TV room? living room?
Why not the middle of the room?
Please be more specific...

Room is a 22' x 18' living / family room with a TV. The ceiling height in the 18' direction slope's up from 12' to 18', which creates a triangle in the ceiling. I'm thinking that the fan should be biased to-wards the deepest part of the triangle in order to affect as much of the air mass as possible and therefore would not be in the center of the room. What are your thoughts?

Center of the room. No question.

For higher ceilings I like them to be in the <1/3 to 1/4 of the way down off the ceiling. Meaning if the ceiling is 18' high I'd want it between 4-5' down.