No power of natural air convection fan is the use of the principle of nature, any parallel to the direction of air flow into a bottom-up speed and vertical air flow to improve indoor ventilation effect of a device, it does not use electricity, no impatient tone, long run, eliminate indoor heat, moisture and bad smell. 
 Series of non-powered roof fans come out naturally, thus breaking the traditional ideas, traditional wall exhaust fan installed in power, can not effectively improve the existing large steel plant wide air environment, the traditional fan 2 to 3 meters on the surrounding range have a demonstrable effect, the new power roof fan with its unique design, forced ventilation effect by the large and medium-sized enterprises favor, but the high economic cost and subsequent maintenance chores, so that small and medium enterprises only hope Ertan the roof line without power fans with its unique natural economical and practical, efficient and energy saving, environmental protection and the associated fan power comparable to the roof, which according to the air and the air flow principles of natural law, rationalizing set in the roof top of a smooth velocity discharge of polluted indoor heat and gas, improve the working environment and protect employee health, increase work efficiency. 
 Zero-cost operating costs, the economic cost of installation, low maintenance costs, considerable energy saving effect of quality products.