Standard ridge vent produces 18 square inches of ventilating area per lineal foot.
Attic air flow calculation.
Let s see how a standard ridge vent product will calculate out.
Length x width of attic in feet 150 total sq.
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.
Taking advantage of this natural process referred to as passive ventilation is the most common way to vent an attic.
Of total vent space needed.
A 50 x 30 attic would have a total area of 1 500 sq.
How to determine the number of attic vents.
That means air can t flow from the soffit vents to the roof vents.
Home attic vent calculator for years we have been working with architects and specifiers to ensure affordable roof ventilation that upholds building code standards.
11 12 roof pitch and higher increase the amount of ventilation by 30 percent.
Our roof is 50 feet long so using a standard product we will get 900 square inches of ventilating space.
7 12 to 10 12 roof pitches increase the amount of ventilation by 20 percent.
Ft divided by 150 equals 10 sq.
Multiply the length of the attic times the width in feet to find the attic area then divide by 150 to find the total square feet of vent space needed.
Proper air ventilation in the roof prevents costly problems like.
Nine hundred square inches equals 6 25 square feet.
Attic mold rotting of roof sheathing and framing shortened roof life cracked paint and siding failure or an overheated home.
The solution is to add baffles which allow air to flow past the insulation photo 9.
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.
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.
Soffit vents allow outside air to.
Daily activities in your home such as showering dishwater laundry or having the furnace on generate heat and moisture in the air.
Hot air exhaust vents located at the peak of the roof allow hot air to escape.
Up to 6 12 roof pitch use the standard formula as explained in this article.
Baffles are available at home centers.
Proper air circulation through the attic space helps lower cooling bills and prolongs the life of roofing materials.
Calculate the total vent area needed.
Enter square footage calculate or enter the square footage of the attic or area to be vented.
