Fan blade rotation is determined to be either clockwise or counterclockwise when viewed from the air discharged side.
Attic fan blade orientation.
Air will blow in the other direction towards the back.
The leading edge of the blade will be covered with dirt.
This is the best ceiling fan direction for air conditioning since it makes the air feel cooler than it is.
Whole house fans are used to blow hot air out of the attic by sucking cool air through the house up though the whole house fan and out though the gable vents in the attic.
A ceiling fan should rotate counterclockwise in the summer so the blades push cooler air down in a column.
If a blade is angled down and the fan turns in the same direction as the blade angle it will blow forward.
Some whole house fans however can be reversed to spin in the opposite direction.
The motor s nameplate depending on manufacturer may contain information on direction of blade rotation.
These fans are usually wired to run in one direction.