This ADD direct drive tube axial fan provides superior performance and requires little or no maintenance, according to the manufacturer. The ADD tube axial fan housing is constructed of heavy-duty welded steel and angle ring flanges, with a spark-resistant, cast-aluminum airfoil axial impeller. The fan is available in diameters from 12 inches through 42 inches, with direct-drive capacities ranging to 29,000 cfm. Other features include factory-set adjustable pitch blades and air-dried enamel paint finish. The device can be mounted in ductwork in any position.

Continental Fan Manufacturing Inc., 203 Eggert Road, Buffalo, NY 14215; (716) 842-0670; fax (716) 842-0611; www.continentalfan.com.