The KV-4 is the Keepa Attic Vent with a 4 inch inner diameter and an 11 inch tall collar. This attic vent has a Net Free Area (NFA) of 12 sq. in. This particular Keepa Vent comes with a standard 10” x 10” square flange.
The Keepa Attic Vent is ideal for ventilating low slope or flat roofs. Likewise, it is typically used for ventilating attics and or plenums as a roof exhaust vent or as an air intake roof vent. The vent head is removable therefore allowing easy installation on EPDM or TPO roofs. In addition, this attic vent is compatible with membrane roofs. Click here to view our installation guides.
To determine the number of vents you may need, see our Vent Calculator.
The Keepa Vent removes moisture from the attic during the winter and heat during the summer to extend the life of the building structure. The 11 inch collar height is good for locations that accumulate high levels of snowfall. In addition, the round design is aerodynamic to withstand wind speeds up to 200 mph.
As a result, this attic vent is suitable for installation in all climate zones. Most importantly, the Keepa Attic Vent comes in an array of sizes with an optional curb mount flange for additional clearance or tailpipe adaptor allowing for duct ventilation.
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.