Calculating Attic Ventilation Needs

Enter square footage calculate or enter the square footage of the attic or area to be vented.

Calculating attic ventilation needs.

Calculate the total vent area needed. 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. Result of item 1 300. Hence you would need two square feet 600 300 of attic ventilation.

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. Standard attic vents like af 50 s ventilation fans or solar powered attic fans. Gaf attic ventilation calculator. Intake vents located at the lowest part of the roof.

His home is 48 feet long and has a ridge vent that measures 46 feet. Of total vent space needed. Use avp s roof vent calculator to determine the number and size of exhaust vents you will need. Let s use the following simple ranch house for an example.

How attic ventilation works. Attic ventilation works on the principle that heated air naturally rises primarily utilizing two types of vents. 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. Use this calculator to help determine the proper amount of attic ventilation based on u s.

Other options to meet your attic ventilation needs are. Length x width of attic in feet 150 total sq. Ft divided by 150 equals 10 sq. Ridge vents are one of the easiest ways to meet roof venting requirements.

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. The house measures 30 feet by 50 feet. The ridge vent is installed on the peak with nails and shingled over for aesthetic purposes. For balanced ventilation an equal amount of intake vent area net free area should also be installed.

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. Calculating ventilation area of attic kitchen ventilation text. 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. 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.

Divide the square footage item 1 by 300. Calculate the square footage of the attic space. A 50 x 30 attic would have a total area of 1 500 sq.