Calculating Attic Ventilation Needs

Use this calculator to help determine the proper amount of attic ventilation based on u s.

Calculating attic ventilation needs.

Let s use the following simple ranch house for an example. Length x width of attic in feet 150 total sq. Calculate the total vent area needed. The ridge vent is cut back 1 inch on either side of the ridgeline which yields a total area of 7 67 square feet of ventilation.

The two square feet is divided equally between the intake and the exhaust one square foot for each. Gaf attic ventilation calculator. His home is 48 feet long and has a ridge vent that measures 46 feet. 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.

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. The ridge vent is installed on the peak with nails and shingled over for aesthetic purposes. Use avp s roof vent calculator to determine the number and size of exhaust vents you will need. Ft divided by 150 equals 10 sq.

Result of item 1 300. Attic ventilation works on the principle that heated air naturally rises primarily utilizing two types of vents. Intake vents located at the lowest part of the roof. 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.

Ok to determine how much ventilation area you need for your house all you need to know is the square foot area of the attic to be ventilated. For balanced ventilation an equal amount of intake vent area net free area should also be installed. A 50 x 30 attic would have a total area of 1 500 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.

His next step is to calculate the total amount of ventilation that he has in his attic. Ridge vents are one of the easiest ways to meet roof venting requirements. Calculating ventilation area of attic kitchen ventilation text. Other options to meet your attic ventilation needs are.

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. Enter square footage calculate or enter the square footage of the attic or area to be vented. Calculating attic ventilation requirements. The house measures 30 feet by 50 feet.

Calculate the square footage of the attic space. Hence you would need two square feet 600 300 of attic ventilation. Of total vent space needed.