How Many Square Feet Per Roof Turbine

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.

How many square feet per roof turbine. The next step is to select a suitable exhaust vent and intake vent that fits the roof design for best performance and best aesthetics. Of vented area for every 300 sq. Attic must have 5 sq. The quotient is the amount of ventilation you will need for your attic.

How many turbine vents you will need depends on a number of factors including the size and type of building. Having the correct number of turbine vents will provide an effective and balanced system. Based on your 1100 sq. Depending upon the diameter of the vents and the wind speed outdoors the turbines can expel vast quantities of humid air before it becomes a problem.

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. Furthermore this will ensure that a continuous supply of air moves through the desired space. Now take the square footage number and multiply it by 144. 1 000 divided by 300 3 33 total square feet.

Take this number and divide it by three hundred. 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. 1 000 divided by 150 6 66 total square feet 50 intake 3 3 sq. 2 200 2 1 100 square inches of exhaust net free area needed.

This will give you square inches instead of square feet. 50 intake 1 7 sq. And this guideline you ll need a minimum of. 50 exhaust 3 3 sq.

Thus if your attic is 450 square feet you need roof vents equaling 3 square feet. Then divide that calculation by 144 to convert the square inches to square feet. 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. 1 100 square inches of intake net free area needed.

First find out the square footage of your attic and sketch it onto the graph paper. As a general rule your roof needs 1 square foot of vent area for every 150 square feet of attic space. Thousands of cfm per hour. Near ridge of the roof.

For example a 6 by 12 inch soffit vent has 72 square inches which when divided by 144 results in a 0 5 square. Say the contractor is standing in front of a house that has an attic with 2 200 square feet.