How Many Roof Vents Does A House Need

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.

How many roof vents does a house need.

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

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 example a 6 by 12 inch soffit vent has 72 square inches which when divided by 144 results in a 0 5 square foot opening. For proper cooling and efficient operation any whole house comfort ventilator requires adequate unobstructed outlets in the attic through soffit vents grilles or louvers.

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. 6 measure the radius of round vents or take half the diameter of the. Advantages of proper roofing ventilation. These specialty vents do not affect the.

Choose one of the following products to meet the recommended exhaust nfva of 528 square inches. Thus if your attic is 450 square feet you need roof vents equaling 3 square feet. You ll need the square footage of your attic to calculate the number of roof vents that you should need.