Roof Vents By Sq In

Of net free area.

Roof vents by sq in.

These vents are static vents that are placed over holes in the roof close to the roof ridge. Ventilation manufacturers assign an nfa value to the non motorized vents they make. Building codes vary. Proper attic ventilation consists of a balance between air intake at your eaves soffits or fascias and air exhaust at or near your roof ridge.

The ridge vent is cut back 1 inch on either side of the ridgeline which yields a total area of 7 67 square feet of ventilation. It offers 150 square inches of net free venting area which means fewer roof penetrations saving time and money. It is also a lower profile than most competitors vents which gives it more curb appeal. As a general rule your roof needs 1 square foot of vent area for every 150 square feet of attic space.

In order to facilitate this exchange of warm and cool air the general rule of thumb suggests installing at least 1 sq. More product details close how doers get more done. Recommended usage for this unit is 1 unit per 800 sq. Nine hundred square inches equals 6 25 square feet.

Thus if your attic is 450 square feet you need roof vents equaling 3 square feet. The ross 150 roof vent is a patented design that has been tested and proven to perform. Unlike box vents which are square off ridge vents are usually much longer and thinner. Of vent for every 300 sq.

Our roof is 50 feet long so using a standard product we will get 900 square inches of ventilating space. Of attic space with a minimum intake ventilation of 240 sq. Nfa is the unobstructed area through which air can pass through a vent usually measured in square inches. So the ridge ventilation has exceeded the minimum requirement.

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. Ventsure 4 foot strip heat moisture ridge vent 27 lineal feet required. Attic square footage 2 square inches of exhaust and square inches of intake net free area nfa needed. Standard ridge vent produces 18 square inches of ventilating area per lineal foot.

Roof vents choose one of the following products to meet the recommended exhaust nfva of 528 square inches.