Figuring Attic Ventilation

The federal housing administration recommends 1 square foot of attic ventilation for every 150 square feet of attic space.

Figuring attic ventilation. Calculate or enter the square footage of the attic or area to be vented. 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. Calculate the total vent area needed. A correct attic ventilation system provides for a steady flow of outside air from the lowest part of the attic through the attic to the upper most part of the attic as shown in figure 1.

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. 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. This allows the attic insulation to perform at peak efficiency helping to maintain constant temperatures in your home.

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. The house measures 30 feet by 50 feet. Divide the attic s square footage by 150. Why is it important that the amount of intake ventilation.

Of total vent space needed. Let s use the following simple ranch house for an example. The formula for figuring out the cubic footage of a rectangular solid like the interior of a room is length times width times height. Calculating ventilation area of attic kitchen ventilation text.

Length x width of attic in feet 150 total sq. Ft divided by 150 equals 10 sq. Other options to meet your attic ventilation needs are. A 50 x 30 attic would have a total area of 1 500 sq.

Here are the answers to the five most frequent questions pertaining to calculating attic ventilation. Attic ventilation works on the principle that heated air naturally rises primarily utilizing two types of vents. Calculation q a. 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.

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. If you want to heat or cool your attic space calculating its cubic footage is necessary to determine adequate ventilation. But the shortcut is just as good and faster.