How Many Roof Vents Do I Need In My Roof

They should be divided equally between inlet and outlet vents and they can be used in any combination that will work with your roof s design.

How many roof vents do i need in my roof.

Rounding up you would need ten 10 750 vents. And this guideline you ll need a minimum of. As a general rule your roof needs 1 square foot of vent area for every 150 square feet of attic space. To calculate the number of 750 vents needed divide 480 by 50 to get 9 6 vents.

Near ridge of the roof. The net free area nfa ratingindicates the amount of space each roof vent covers. Because you always want your intake nfa to meet or exceed the amount of exhaust nfa we will take the amount of exhaust provided and divide by the nfa rating of the deck air. You will need to have 1 square foot of vent area for every 150 square feet of attic space.

Thus if your attic is 450 square feet you need roof vents equaling 3 square feet. So if your attic is 450 square feet you will need 3 square feet of vent space evened out throughout the entire space and divided equally between inlet and outlet vents. For example if you have 1200 square feet of attic space you should need at least 4 air vents to ensure proper ventilation. Federal housing authority recommends a minimum of at least 1 square foot of attic ventilation for every 300 square feet of attic floor space evenly split between intake and exhaust.