The Circular Inline Fan is best defined as a fan that is mounted inline (inside or connected to ducting) that is used for extraction purposes. An inline fan does not sit directly on the plasterboard or ceiling, instead it is typically located inside the attic or roofspace a little bit further away from the bathroom. The inline fan is a device that works to remove smells and heat out of a certain space. Its connected to a duct which moves these things up and out of the space and to its opening outside. Circular Inline Fan is very effective.