A portable fan is simply a fan that is not permanently affixed to the wall or ceiling. Portable fans come in all shapes and sizes, from tiny battery-powered fans that can be held in the hand, to large box fans meant to ventilate a whole room. Using a portable fan can be a great way to keep the air moving, moderate the temperature of a room, and supplement the use of an air conditioner to save power.
There are a few different types of portable fans. These include personal fans, box fans, window fans, pedestal fans, and floor fans, among others. Personal fans may be the small, battery-powered handheld ones mentioned above, or they may simply be a small electric fan designed to sit on a desk, table, countertop, or dresser. Handheld personal fans sometimes offer a water misting feature as well, so as the fan spins, a light spray of water will help to cool the user. Electric personal fans often oscillate, but not always.
Box fans and floor fans are similar types of portable fans. A box fan is a large, square fan, generally about two feet (.6 meters) across, whereas a floor fan is often a round fan of a similar diameter. These fans are typically not capable of oscillating, but are more powerful than a personal fan and may be used to assist in cooling an entire room. A pedestal fan, conversely, is often a large portable fan on top of a height-adjustable pedestal. These fans are slightly smaller than floor fans, between one and two feet (.3 and .6 meters) in diameter, but usually oscillate and tilt, and are also capable of cooling a whole room.
Window fans are a type of long, narrow portable fan designed to fit inside a window. A window fan typically includes two smaller fans. The two fans are often capable of being reversed to spin in opposite directions. This means that during the day, a fan can be blowing outside, pulling the warm air inside the house back out of doors. At night, however, the fan direction can be reversed, and the fan can pull the cooler night air inside. The fans inside a window fan unit are frequently capable of operating independently of each other, so one can be pulling air in while the other pushes air out simultaneously; this is helpful to circulate fresh air into a room.
A commercial fan is a type of high-powered floor fan, sometimes also referred to as a barrel fan. This type of portable fan is often very loud, and may be used in garages or workshops to help clear fumes or sawdust. In addition, commercial fans like these are often placed around homes to help paint dry. One would not use a commercial fan on an everyday basis for cooling purposes, however, as it would likely blow dust, papers, and even lightweight objects around the room as well.