Roof Vent Free Area

The nfa is the open area that exists for air to pass through.

Roof vent free area.

Two square feet equals 288 square inches. This vent features an 1 8th inch internal aluminum screen to prevent intrusion by birds or large insects. Should you need to add more air intake ventilation to your attic simply determine the number of vents needed from the table based on your net free area requirements. Base offers added weatherproofing protection and ease of installation.

Roof vents are made from reliable 28 gauge galvanized steel. The calculations before indicated that we needed 2 square feet of ridge or upper roof ventilation. Made in the usa. Sheet metal manufacturers of roof vents roof exhaust fans and solar attic fans.

Calculate or enter the square footage of the attic or area to be vented. Venting products are normally rated with a net free area nfa. So we would need at least six metal vents in addition to the lower soffit ventilation to meet minimum ventilation requirements. Ventsure 4 foot strip heat moisture ridge vent with weather protector moisture barrier.

Large 16 1 2 x 16 1 2 in. The key to effective venting is to balance air intake at your eaves soffits or fascias and air exhaust at or near your roof ridge. Net free area uv 135. Balanced ventilation will prolong the life of your roof while providing energy savings and comfort.

Build your roof empowers you to select each layer and component that goes into your total protection roofing system so that you get the roof you want to protect your home. The passive vent net free area table gives the net free area ventilation for some common roof and gable passive vents. Active ventilation products inc.