The 20 inch Aura Solar Attic Fan is 20 inches in diameter and has a 12 inch tall collar. The model ASF-20-C12 exhausts air out at 2,029 CFM. All 20 inch solar gravity fans come with a standard 25″ x 25″ square flange.
Exhaust fans with a collar height of 12 inches or greater are typically for low slope or flat roof ventilation. However, if installed less than 4 feet from the peak, this fan can go on a 0/12 to 5/12 pitch roof in climate zones 1-6.
The Aura Solar Fan is ideal for ventilating steep slope roofs. It will remove heat during the summer and moisture during the winter to provide ventilation all year. Keeping the attic dry and cool during the winter will preserve attic insulation and prevent ice dams.
20 inch diameter fans are considered a commercial size and therefore should be used in commercial settings. For those looking to ventilate their homes, please view roof vents with a smaller diameter.
The Aura Solar Fan uses both solar and wind to power the ventilator. Fan only works with solar power when in bright, direct sunlight on South facing roofs.
However it exhausts air continuously even without sun. It works passively due to the Venturi Effect. When the wind blows against the outer louvers this creates a vortex of air within the head. As a result, creating an upward draft which allows air to flow out of the vent.
The 1/8 inch louvers prevent rain, snow, insects, and animals from entering inside the fan.