The clean air exhaust fan is connected to the vent filter plenum to aid in evacuation of air from the vent filter. STANDARD CONSTRUCTION FEATURES Split housing for maintenance easeEven O.D. pipe sizes on inlet and outletNon-Sparking cast aluminum wheel and housingAssortment of wheel sizes to pinpoint your performance requirementsReliabilityWheels both statically and dynamically balancedRustproof OPTIONAL FEATURES Carbon steel or stainless steel constructionInletOutlet damperDischarge silencerX-Proof motor enclosureBelt driven versus standard direct driven