Portable fans are usually used for circulating inside air, rather than moving air into-or-out of the home. These are some of the most inexpensive fans to purchase and have very low operating costs, since they generally use less than 200 watts of power. At six cents per kWh, a 200-watt portable fan can run for 24 hours for less than thirty cents.
With portable fans, it is fairly easy to direct the air flow by simply moving the fan. Some automatically oscillate giving broader coverage of the room by sweeping back and forth.