With industrial, commercial and light steel construction, light steel construction and ventilation were also concerned by the series of natural fan power is the use of natural convection of air, parallel to the direction of any air flow, and accelerate the transformation of a bottom-up vertical air flow to improve indoor ventilation efficiency the fruit of a plant, which do not use electricity, no hypomanic sound, long-term operation to remove indoor air, moisture and been series of non-powered ... ...[More..]