The Vortex Powerfan S-Line is a revolutionary series of fans that combine energy efficiency, ultra-quiet operation and a collection of advanced technologies that deliver unparalleled performances. An extremely energy-efficient AC brushless motor powers the patented mixed-flow dual impellers. Built with double-insulated walls, noise is reduced to levels that were previously thought to be unattainable. All S-Line models are assembled with highly impact-resistant polycarbonate casings, an integrated back draft damper, and a mounting bracket designed for quick and easy installation. The S-Line models feature a 10-year warranty.