What type of fan can I use to move air between rooms?

To move air between rooms, you need a fan designed for high airflow and focused circulation rather than just oscillating in one room. The most effective types are doorway fans, box fans, and air movers. A box fan placed in a doorway or hallway can push air from one room to another very effectively and is inexpensive. For better performance, use two fans to create cross ventilation, one fan blowing cool air in from one room and another fan exhausting warm air out in another room. Doorway fans are specifically designed to mount in a doorway or above a door to transfer heat from a warm room with a fireplace or heater to cooler rooms. Whole house fans mounted in the ceiling can pull air through the entire house. For targeted air movement between rooms, especially for water damage drying, low-profile centrifugal air movers are excellent because they produce high velocity focused airflow along floors that can push air down hallways and around corners. Axial air movers are also good for moving large volumes between rooms. Avoid small desk fans or tower fans for this purpose as they do not move enough air over distance. If you want to move cool air from an AC room to a hot room, place the fan low on the floor blowing from the cool room to the hot room, since cool air is denser and stays low.