How Many Roof Vents Does A House Need

To calculate the amount of attic exhaust area you will need divide the fan s capacity in cfm by 750.

How many roof vents does a house need.

These specialty vents do not affect the. 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. 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. Use the calculator below to find out how many exhaust and intake vents you will need on your house.

Proper attic ventilation offers numerous advantages to the homeowner. Although there are many different types of roof vents to choose from ensuring you have the right number of both intake and exhaust vents is a central part of roof design. Thus if your attic is 450 square feet you need roof vents equaling 3 square feet. Choose one of the following products to meet the recommended exhaust nfva of 528 square inches.

As a general rule your roof needs 1 square foot of vent area for every 150 square feet of attic space. 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. Advantages of proper roofing ventilation. For example if you have 1200 square feet of attic space you should need at least 4 air vents to ensure proper ventilation.

Keep in mind you should always consult with a professional roofing company when determining how many air vents. For proper cooling and efficient operation any whole house comfort ventilator requires adequate unobstructed outlets in the attic through soffit vents grilles or louvers. Rafter vents or insulation baffles install in any rafter space to create narrow gaps that direct fresh air from the soffit vents to the peak of the roof.