Attic Air Flow Calculation

Let s see how a standard ridge vent product will calculate out.

Attic air flow calculation.

Soffit vents allow outside air to. Nine hundred square inches equals 6 25 square feet. Up to 6 12 roof pitch use the standard formula as explained in this article. Of total vent space needed.

Taking advantage of this natural process referred to as passive ventilation is the most common way to vent an attic. Attic mold rotting of roof sheathing and framing shortened roof life cracked paint and siding failure or an overheated home. 7 12 to 10 12 roof pitches increase the amount of ventilation by 20 percent. Home attic vent calculator for years we have been working with architects and specifiers to ensure affordable roof ventilation that upholds building code standards.

The solution is to add baffles which allow air to flow past the insulation photo 9. Calculate the total vent area needed. A 50 x 30 attic would have a total area of 1 500 sq. Enter square footage calculate or enter the square footage of the attic or area to be vented.

Proper air ventilation in the roof prevents costly problems like. Baffles are available at home centers. Proper air circulation through the attic space helps lower cooling bills and prolongs the life of roofing materials. 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.

11 12 roof pitch and higher increase the amount of ventilation by 30 percent. If your attic is well insulated the insulation might be plugging the spaces between rafters just above exterior walls. Length x width of attic in feet 150 total sq. 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 to determine the number of attic vents. 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. Hot air exhaust vents located at the peak of the roof allow hot air to escape. Ft divided by 150 equals 10 sq.

For projects involving vents with motors the calculation formula is different. 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. Standard ridge vent produces 18 square inches of ventilating area per lineal foot. Daily activities in your home such as showering dishwater laundry or having the furnace on generate heat and moisture in the air.