These days, most ceiling fans spin in both directions to provide both updraft and downdraft so you can better use your fan to control airflow and temperature, but how does it work?
Updraft vs. Downdraft
We're all fairly familiar with downdraft - that's the air we feel moving as a fan pushes it down and circulates it around the room on a warm day. Updraft, on the other hand, occurs when a fan (typically on low speed) pulls air up from a room and pushes it along the ceiling and down the walls.
Updraft is used on cold days to recirculate warm air and help create a barrier against the chilly air that's always trying to seep in through the cracks.
Whether you're getting updraft or downdraft doesn't isn't really a matter of the direction the fan is spinning in terms of clockwise or counterclockwise motion, though - it depends on how the blades are angled.
Ceiling Fan Blade Pitch
When we're talking about ceiling fans, "pitch" refers to the angle of the blades relative to the horizontal plane of the ceiling (or the floor, depending on how you want to look at it). The more severe the angle, the more air your fan is going to push.
Think about fan blades that are perfectly horizontal - the blades will catch very little air. Tilt the blades a little, though, and voila! Now you're moving air.
Pitch varies between fans, but is also adjustable on many fans. Check the product description before you buy for more information and keep in mind that higher numbers equal more pitch.Visit the Ceiling Fan Info Center