These powerful, versatile fans are ideal for many applications within the growing environment. Originally designed for use as exhaust fans, they are also well suited for use as plenum fans or for introduction of air into convection tubing (order tubing one size larger than blade diameter of fan: i.e., for 12" blade diameter, order 16" ducting). Fully enclosed, thermally protected motors are designed for use in high-humidity environments. Heavy molded polyethylene housings with integral shutters won't rust or corrode and have a lifetime warranty. A flange around the base of the housing allows for easy mounting of the fan. Dual-voltage motor operates at either 115 or 230 volts and can be used in conjunction with the VMS400S and VMS550S Speed Controls. Available in five different sizes/capacities.