When shopping for a ceiling fan, there are a few things to consider. First, you want a fan that works within the dimensions of the room in which you're installing it. Calculate the size of the room by measuring the length and width and multiplying these numbers to get the square footage. A 52" fan should be used in a 225-400 square foot room and a 42" to 44" fan should be used in smaller areas.
Adjust your new fan to rotate counterclockwise if your ceilings are 8' in height. If your ceilings are 10' or higher, set it to rotate clockwise.
Check the floor-to-ceiling height of the fan blades. You can do this by measuring the floor-to-ceiling distance and subtracting for the part of the fan that will extend below the ceiling down to the lower blade surface. An absolute minimum height of 7' is recommended. Building codes in your area may reinforce this.
If the floor-to-ceiling distance is too little, check into a low ceiling mount fan. With some models, the fan blade height can be increased by as much as 10". Remember, though, that you need at least 12" between the ceiling and the tops of the fan blades for proper airflow. Having 18" is better if the space is available.