How to efficiently circulate air to keep room cool?
A common method of equalizing the temperature across a room is to add a ceiling fan. 


Cool air tends to stay near the floor, and a fan can be set to pull the air upwards.  As it hits the ceiling, the air is pushed outwards to the edges of the room. Because cool air is heavier than warm air, it then moves downward, better distributing the temperature. 

A very low setting can be used to avoid noise and strong air currents.  This is easier with fans that have variable speeds, which is common with remote control types.

This technique is also used to circulate warm air for heating systems that need help with temperature distribution.

SUPPLEMENT

The ceiling fan should be placed near the center of the room. Most fans are reversible. The fan should be set to blow upward, if possible.

Floor fans can also be used. 



Similarly, a pedestal fan.



If using a floor or pedestal fan, place near the air conditioning flow and direct the fan upward and toward the other end of the room.