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 many square feet per roof turbine.
1 000 divided by 150 6 66 total square feet 50 intake 3 3 sq.
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.
Attic must have 5 sq.
1 100 square inches of intake net free area needed.
The quotient is the amount of ventilation you will need for your attic.
This will give you square inches instead of square feet.
Now take the square footage number and multiply it by 144.
50 intake 1 7 sq.
For example a 6 by 12 inch soffit vent has 72 square inches which when divided by 144 results in a 0 5 square.
Then divide that calculation by 144 to convert the square inches to square feet.
Of vented area for every 300 sq.
Say the contractor is standing in front of a house that has an attic with 2 200 square feet.
As a general rule your roof needs 1 square foot of vent area for every 150 square feet of attic space.
Near ridge of the roof.
1 000 divided by 300 3 33 total square feet.
A largely arbitrary rule of thumb that s been adopted into most building codes calls for 1 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.
Furthermore this will ensure that a continuous supply of air moves through the desired space.
How many turbine vents you will need depends on a number of factors including the size and type of building.
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.
2 200 2 1 100 square inches of exhaust net free area needed.
First find out the square footage of your attic and sketch it onto the graph paper.
50 exhaust 1 7 sq.
The next step is to select a suitable exhaust vent and intake vent that fits the roof design for best performance and best aesthetics.
Thus if your attic is 450 square feet you need roof vents equaling 3 square feet.
Thousands of cfm per hour.
Having the correct number of turbine vents will provide an effective and balanced system.
50 exhaust 3 3 sq.
Based on your 1100 sq.
Take this number and divide it by three hundred.