One of three solar-powered attic fans from the manufacturer, the 9915TR features a 15-watt solar panel and a 14-inch fan capable of ventilating up to 1,750 square feet of attic space. The unit’s deflector design provides a smooth air exhaust passage and increases the overall volume of air movement, the firm says. A solar controller option allows the unit to switch to AC power when solar power is not available and includes a humidistat and thermostat to manage attic humidity levels and temperatures. 866.446.0966. www.ussunlight.com.