1.This fan adopts advanced frontward open system,butterfly type,with two semicircle shutter doors,wind resistance is small,good air-tightness and high efficiency.

2.For the cone part ,adopt new design,plug-type connection,not nedd many bolts and nuts for tightening as before,intensity of  labor is reduced,also improve aesthetic results of fan.

3.The belt tensioner device made of aluminum-magnesium alloy,non-deforming,long service life,This device make the belt inside tigh up,effective for avoiding the belt  distortions in reverse direction,so prolong the belt life time,saving cost.

4.When the two semicircle shutter doors close,the rubber sealing ringmake god air-tightness.In different condition,not run all the fan,the air could pass through the evaporative cooling pads or air inlet only,so that  greatly improve the fan efficiency,(as compared with different type of same size fan,improve eficiency 15-20%)

5.The fan motor installed on top left corner,effective protection of the motor,Avoid wind resistance.And the motor panel connection is reasonable,fixing fan frame more stronger.