The 18 inch Pop Vent Air Intake Vent is ideal for maintaining proper attic ventilation. The PV-18-C4 is 18 inches in diameter with a 4 inch tall collar. In other words, this vent has 4 inches of clearance between the base and the inner louvers. In addition, the 18 inch Pop Vent has 254 inches of Net Free Area (NFA) and a standard 28” x 28” square flange.
18 inch diameter roof vents are commercial size, therefore, are ideal in commercial settings. For those looking to ventilate their homes, please view roof vents with a smaller diameter.
This 18 inch attic vent is suitable for installation in climate zones 1-3.
To determine the number of vents you may need for proper attic ventilation, see our Vent Calculator.
The Air Intake Roof Louver provides fresh air into the attic or plenum. Without proper rooftop ventilation, heat and moisture may cause decay of the structure. This roof vent also helps to keep insulation dry in the winter to prevent the growth of mold.
Additionally, the round design is aerodynamic to withstand wind speeds up to 200 mph. The 18 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.