Fans are found circulating air in many rooms of Quadwrangle Manor. Fans blowing vertically are often used to push light objects upward, mostly safes and furniture in the Fluffy Dimension which the player can ride on. Fans that blow horizontally can be used to hold light objects against walls which the player can use as steps to reach higher areas. In other instances fans become an obstacle and the player must figure out how to keep objects stationary while they block lasers or hold down pressure plates.
Fans aren't lethal to the player, typically blowing them backwards if they get too close in any dimension other than Slow Motion.
Being in the Slow Motion Dimension can allow you to pass through fans, sometimes leading to other areas.