One of three solar-powered attic fans from the company, the 9915TR features a 15-watt solar panel and a 14-inch fan for a ventilation capacity of 1,750 square feet. According to the manufacturer, this unit’s Smooth-Air Deflector design provides a smooth air exhaust passage and increases the overall volume of air movement. The panel tilts or rotates for orientation and it has an optional thermal switch. U.S. Sunlight Corp. | | 866.446.0966.