Power fan is the use of the nature of the natural wind speed to promote the principle of the turbine rotation of the fan and the indoor and outdoor air convection, any parallel to the direction of air flow, accelerated into the bottom-up vertical air flow in order to improve indoor ventilation effect of a device. The fans do not use electricity, impatient tone, long-term operation. Since the non-power fan according to the air 
 Rationalization of natural law and the air flow principle, set at the top of the roof, and can rapidly discharge the indoor heat and foul gases, improving the indoor environment. 
 The Liaocheng sun Stainless Steel Co., Ltd. specializing in the production of free power - roof ventilation products, with more than 20 sets of large and medium-sized stamping equipment. With ventilators researchers, more than 160 product models, 200, 300, 400, 500, 600, 680, 800, 880, and all kinds of special-shaped ventilation, has a professional installer. Welcome customers counterparts at home and abroad visit the guide. 
 In recent years, under the joint efforts of the company engineering and technical personnel, factory production of free power - roof ventilation domestic specifications, the largest and most complete variety of manufacturers. 300, 360, 450 is mainly used for residential buildings, the floor of the villa roof ventilation mouth, 500, 600, 680 is mainly used for factory workshop and large public places ventilation exhaust. Full stainless steel body, cast aluminum support a special double-sealed bearings. Product sales over the surface of the country, service first class