Greenheck’s Model APD plenum fan is a direct-drive fan with the wheel connected to the motor shaft. Model APD has no fan shaft bearings or belts to maintain, which officials say eliminates the cost and maintenance associated with traditional belt-drive plenum fans. The fan is constructed from a formed and bolted galvanized steel frame with a welded and coated, seven-bladed, backward-curved steel wheel. Model APD’s compact size and smaller footprint allows for easy installation in applications like air-handler retrofits or when pressurizing a plenum room. It offers an operating range up to 18,000 cfm and external static pressure up to 10 inches water gauge.