"Exhaust Fan" Depending on how the steam emission selection: If the fan is drawn into the pipe the steam discharged from the outdoors needs, you need to select this pipeline fan, exhaust steam if other devices do not need to connect pipes, etc, directly discharged into the the atmosphere, the choice of such a vertical-type fan. Generally, early in the design, will design a fan of this building is now installed, the reason why the design of this fan, the one to air convection will achieve the purpose of an air exchange, so that the indoor air to keep fresh and odor-free, and secondly also to a number of harmful gases by the indoor fan to discharge this room.