Hi Lilacben
Try changing the height from the cieling (I presume it is a cieling fan..coz you cant get the blades wrong on a pedestal fan!!) My theory...a higher circulation area above the fan = more air. On the contrary...if it is closer to the cieling = less circulation area (I could be wrong).
And also your cieling may be too high up for the fan type....
Further references :-
http://www.csnceilingfans.com/asp/show_content .asp?CpID=146&settab=4#Downrod
[http://www.hunterfaninternational.com/support/fan-faq.php?origx=38#17]
What is the difference in having a ceiling fan installed close to the ceiling versus on a downrod - I have seen both ways.
For maximum performance and greatest energy savings, ceiling fans should be installed approximately 2.3 meters above the floor. Extension downrods are used to properly position fans from ceiling heights greater than 2.3 meters. For example, a 3.65 meter ceiling would need a 1 meter downrod to position the fan at 2.3 (30cm must be allowed for the distance from the top of the fan motor to the switch housing bottom). [http://www.hunterfaninternational.com/support/fan-faq.php?origx=38#17]
Hope this helps and hope you have a cooler summer. :)
PS: I am NO engg. this is just a suggestion and is not to be taken as advice; as a whole or parts of herein. This is a suggestion only and I take no responsibility of any action that may arise due to this...(just to cover my own back!!!)