Induced fan is part of the ventilation system without inducing duct jet blast it with fan, exhaust fan composition of the entire system. When using ductless jet ventilation system can save the cost of design, manufacture, installation duct and other ancillary works, which is part of the cost is much more expensive than using the induction fan unit, but also with the whole level of the ventilation duct, air blower exhaust fans need much less pressure than when using the pipe, so that you can opt for a lower amount of wind pressure fan, so that the desired reduced dramatically reduce operating costs investment costs. When supply and exhaust machine so that you can opt for a lower amount of wind pressure fan, so that the desired power is reduced, significantly reducing operating costs and investment costs. When supply and exhaust engine stops running, induced fan still running, play the role of local ventilation. Induced fan built-in high efficiency centrifugal fan, with a significant low noise, small size, light weight, easy loading (vertical horizontal installation can be), easy maintenance, has been widely used in supporting the underground parking, gymnasium, workshops, warehouses, ventilation shopping malls, supermarkets, entertainment and other large occasions.