The Pop Vent Roof Louver is used for ventilating steep slope roofs. PV-20-C2 is a 20 inch diameter roof vent with a 2 inch tall collar. In other words, this vent has 2 inches of clearance between the base and the inner louvers. The PV-20-C2 has 314 inches of net free area (NFA) and comes with a 30” x 30” square flange.
If installed on the upper portion of the roof, no more than 18 inches down from the peak, this attic vent can go on a roof with a pitch of 4/12 or greater in all climate zones. The 20 inch Pop Vent is great for commercial roof applications whereas if you are looking for residential ventilation we recommend looking into a smaller size.
The Pop Vent comes in an array of diameters and collar heights allowing for installation in any climate zone. See the Climate Zone Chart to determine the proper collar height for installation in your area.
To determine the number of vents you may need, see our Vent Calculator.
The Air Exhaust Roof Louver removes moisture in the winter and heat in the summer to extend the life of the building structure. It helps to keep insulation dry in the winter to prevent mold. In addition, the round design is aerodynamic to withstand wind speeds up to 200 mph. The 20 inch Pop Vent is great for residential roof applications because of its low profile. It can also be painted to match the color of the asphalt shingles.
The diameter size of all roof vents determines the Net Free Area, also known as the "NFA". NFA is the measured amount of opening each vent offers at each specific size. to be available for venting air through a specific vent size. The calculator below will find the overall number of vents needed to effectively ventilate the targeted attic space.
Once you have the area, the numbers shown below are the number of vents of that size which would ventilate the specified area with both 1/300 and 1/150 rule.
The roof vent calculation values shown above are for the exhaust portion of the roof. The same amount of net free air inches is needed for air intake as well. Proper roof ventilation consists of 50% air exhaust and 50% air intake.