It depends on the pitch (angle) of the blades. On most, it's counter-clockwise. Counterclockwise in the summer for cooling and clockwise in the winter for dispersing warm air.
Summer = clockwise Winter = counter-clockwise
Depends on how the blades are angled. In winter, you want it to blow the warm air off the ceiling, to the floor. In summer, you want it to pull the cool air upwards.
Counter Clockwise. Push air down (down position on most fans)
For summer use, the airflow should go down directly from the fan to the floor. For winter use it should pull the air from the floor towards the ceiling so it flows across the ceiling and around the room. So as to whether it should be clock-wise or counter clock-wise, that would depend on the angle of your blades. It's best to just stand under it when it's on. In the summer you should feel the air blowing on you from the fan and in the winter you shouldn't.
lay on the floor and look up at it. If it is moving the same direction as a clock it is moving clockwise. Hold a piece of tissue paper at a corner such that it is near (but not touching) the fan blades. If the fan lifts the paper toward the ceiling then it is rotating clockwise. This is best for winter. If the fan pushes the paper toward the floor (causing a breeze) then it is rotating counter clockwise. This is best for summer.
Fans should spin counterclockwise in the summer. The counterclockwise rotation pushes cool air down, while clockwise rotation can be used at a low speed in the winter to pull cool air up and push warmer air down.Keep in mind, though, that ceiling fans don't actually cool rooms—they just create a breeze that has a wind chill effect, making you feel cooler. So you can turn the fan off if nobody's home.
With a typical fan, run the fan counter-clockwise in the summer, and in the winter, run the fan clockwise at a low speed. In the summer, blow the air down to directly cool you. If you have a large room, and you are on the outside of the room, you may want to run the fan in the opposite direction. In the winter, blow the air up on slow to pull the cool air up, mixing the cool air with the warm air at the ceiling, and pushing the air across the ceiling to the walls, then coming down the walls, and minimizing wind chill.
For most models your ceiling fan blades should be turning counter clockwise in the summer. As a general rule, the blades need to spin in the direction of the slope on the blades to create a downward draft which makes the air feel cooler. You should feel a draft or breeze when you are standing underneath the fan if it is turning in the right direction. If you do not feel that then you need to switch it to the other direction.
[1] It depends upon whether the fan's standard, or not. [2] Standard refers to how most fans are made. And most are made so that counterclockwise is what's needed for summer cooling, clockwise for winter heating. Non-standard's the opposite. [3] How to tell the difference? Check to see which way the blades rotate when the switch is up, as it should be for winter, or down for summer. Stand underneath the fan. With the former, at the highest setting, there shouldn't be a cool breeze in the face. With the latter, there should.
down
In winter, fan should blow down,heat rises,get it back. In summer ,fan should blow up for a 2 story vaulted ceiling,to circulate air but not blow down hot air.On a one story in summer it can blow either,but it's a prefference.Up is ok,but down you get a lower cool index feeling.
It depends on how the fan blades are angled. If there angled right at 45 degrees then it should spin clockwise but if angled left 45 degrees anticlockwise. Please improve this answer since i am 11.