To purchase the proper sized ceiling fan, you must know the square footage of the room. Measure the length and width of the room and multiply the numbers together. For example, a 10-by-10 foot room would be 100 square feet. The Ceiling Fans web site recommends a 42-inch fan for this size room. The number in inches refers to the span of the blades.
Room and Blade Size
Ceiling fans come in a range of sizes to fit homeowners' needs. Small fans that have blade spans in the 29 to 36 inch range are used in rooms of up to 75 square feet. Rooms from 76 to 144 square feet need a fan that is 36 to 42 inches. The next fan size is 44 inches and works in rooms 144 to 225 square feet. The largest fan is 50 to 54 inches and will benefit a room of up to 400 square feet. For larger rooms, divide the room size in half and place two fans on the ceiling.
Mounting Styles and Ceiling Height
There are four choices for mounting systems. A standard mount is used for a flat ceiling with an average ceiling height of 8 to 9 feet and the down-rod is about 3 to 5 inches long. Extended mounts are needed when the ceiling is higher than 9 feet. The extension rod can be adjusted to a length of 120 inches. Ceilings built with an angle need sloped mounts. Flush mounts fit closer to the ceiling and are used for ceiling heights below 8 feet. The tips of the blades should be at least 2 feet from the walls.
Ceiling fans aren't just for warm weather use. Set the unit to circulate the blades in a counterclockwise direction. This pushes the air down and helps to create a breeze to cool the skin in warm weather. Reverse the direction of the blades in colder months to the clockwise direction and run the fan on the lowest speed. This direction makes an updraft that forces the warm air collected near the ceiling to go down.