All series of shinyway ventilation Fan are designed by CAD or CAM. The product has advantages of less investment, high air pressure, low noise, low consumption, smoothly running, long service life , beautiful looks and so on, The shutters is waterproof and dustproof which can automatically open, not only to providing fresh air ,but also to take away the smelly air, this products is the best choice for greenhouse and factory ventilation cooling system.; By negative pressure ventilation effects it can get indoor outdoor air exchange, discharging indoor heat and smelly air, inflowing in the outdoor natural and fresh air to get the outcome of indoor temperature decrease.