Calculating Attic Ventilation Needs

For balanced ventilation an equal amount of intake vent area net free area should also be installed.

Calculating attic ventilation needs.

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. Divide the square footage item 1 by 300. Use our easy 3 step attic ventilation calculator to determine your attic square footage and ventilation needs. Calculate the square footage of the attic space.

Calculation q a. Divide the attic s square footage by 150. Use avp s roof vent calculator to determine the number and size of exhaust vents you will need. Tips for assessing your needs.

Other options to meet your attic ventilation needs are. 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. 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. The house measures 30 feet by 50 feet.

Here are the answers to the five most frequent questions pertaining to calculating attic ventilation. The federal housing administration recommends 1 square foot of attic ventilation for every 150 square feet of attic space. Calculating attic ventilation requirements. 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.

Calculate or enter the square footage of the attic or area to be vented. Result of item 1 300. Ft divided by 150 equals 10 sq. The two square feet is divided equally between the intake and the exhaust one square foot for each.

Length x width of attic in feet 150 total sq. Of total vent space needed. Hence you would need two square feet 600 300 of attic ventilation. Let s use the following simple ranch house for an example.

Standard attic vents like af 50 s ventilation fans or solar powered attic fans. But the shortcut is just as good and faster. If you are in the puget sound area of washington state and would like to have a free attic ventilation evaluation or roof estimate please contact us at 253 445 8950 or fill out our quick estimate form. Most attic ventilation manufacturers list the longer formula on their websites and inside key product brochures.

Calculate the total vent area needed.