Stove fans are small fans that are usually set on top of a wood-burning stove, although they can be put on top of anything warm, like an oven. A stove will slowly radiate heat into the surrounding room, but it can take a long time for this to warm up a room. A fan will make air move past the stove and into the room, which will make the room warm up much faster. (This type of heat is called "convection.")