I have this exact ceiling fan, and so far it has worked nicely. It is mounted in my bedroom, I believe height to floor is about 12 feet and the rod from the ceiling to the actual fan is about 18 inches (estimates here, if you want more specifics I could go and measure).
But for all of summer it was blowing fine - pretty powerfully, but largely hot. Now that the climate has changed and the breeze is cooler, I literally feel absolutely NO AIR below it. When I hold my hand beside it, I can feel breeze up there - almost as if it is sucking air from the bottom and pushing it to the top.
I haven't tested this theory fully yet, by say taping a piece of paper to the roof and seeing how it responds when the fan is turned on, but a lot of this is anecdotal just based on what me and my wife feel.
Is there any reason that the air flow would reverse, without any explicit reason. I was looking for a switch or something on the fan, and I can't find one - so I don't think someone could have flipped it while it was being cleaned, or is there some hidden mechanism that I am unaware of?