Master Flow Green Machine 900 -CFM Black Plastic Hybrid electric/solar Power Roof Vent

The GAF Master Flow 25-Watt Low Profile Dual Powered Roof Mount Exhaust Fan will help reduce excess heat and moisture from your attic to protect your roofing system from premature deterioration. And, its low profile design helps the look of your finished roof. The patented (Patent # 8,915,778) Next Generation Dual Powered unit will run on free solar power (750 CFM) when the sun is shining on the solar panel but will automatically switch to house power (900 CFM) if it is cloudy or nighttime. Hot attic air is removed by the fan as fresh air is drawn in through your existing intake vents. On house power, the 24-Volt DC brushless motor is extremely efficient as it uses 75% less power than a typical wired attic fan. With the Dual Powered unit, you have the best of both worlds! The impact-resistant, 25-Watt solar panel helps withstand hail and object impact. The recommended usage for this unit is one unit per 1000 sq. ft. of attic space with a minimum intake ventilation of 560 sq. in. of net free area.