Attic fan helps cool up to 2,200 sq. Compact fan size with hemmed dome for a sleek look. High efficiency attic fan motor with adjustable thermostat. The GAF Master Flow ERV5 Power Roof Vent is a great overall investment in attic ventilation. It can quickly remove a larger volume of hot and/or humid air from your attic when compared to static ventilation.The ERV5 model Power Roof Mount Vent can move air at a rate of up to 1250 cu. It is designed for attic spaces up to 2200 sq. Energy efficient uses up to 55% less electricity than typical competitors' vents (based on GAF testing at 120-Volt). Helps reduce energy costs and helps prolong the life of the roof and shingles. Galvanized steel construction for durability. Excellent for roof slopes 3:12 to 12:12. Heavy-duty internal screen helps prevent animal infestation.