How Many Turbine Roof Vents Do I Need

This is one of the most important steps.

How many turbine roof vents do i need.

A small 12 inch diameter turbine vent with a constant wind speed of 5 miles per hour mph can remove 347 cubic feet of air per minute cfm from the attic space. Attic must have 5 sq. Having the correct number of turbine vents will provide an effective and balanced system. Federal housing authority recommends a minimum of at least 1 square foot of attic ventilation evenly split between intake and exhaust for every 300 square feet of attic floor space.

As a general rule your roof needs 1 square foot of vent area for every 150 square feet of attic space. Roofing resources during covid 19 for contractors for homeowners. A single 14 inch diameter turbine vent that is subjected to 15 mph winds can expel up to 1 342 cfm of air. Good attic ventilation is important for preventing ice dams in the winter.

If you install a vent that isn t up to code you could end up having to take it down wasting money and time. Let owens corning roofing help you calculate exactly how much ventilation you will need for a healthy and balanced attic with our 4 step ventilation calculator. Thus if your attic is 450 square feet you need roof vents equaling 3 square feet. 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.

To calculate the number of 750 vents needed divide 480 by 50 to get 9 6 vents. One static vent style is the turbine vent which uses wind to power its enclosed fan all it takes is a light breeze to rotate the blades and suck heat out of the attic view example on the home. Also this will give you general guidelines to follow as you complete your project. How many turbine vents you will need depends on a number of factors including the size and type of building.

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 to determine how many vents you need the rule of thumb used to determine the number of roof vents to install is one for every 300 square feet of attic area if your attic has a vapour barrier and one for every 150 square feet of attic area if the attic does not have a vapour barrier. Most policies in place require about one foot of vent area for every one hundred fifty feet of attic space. These can be ridge vents wind turbines or the flat vents your roofer wants to install.

Ft of vent space half dedicated for air intake in the soffits and the other half for exhaust on the roof.