Calculating Attic Ventalation

Let s use the following simple ranch house for an example.

Calculating attic ventalation.

Calculating ventilation area 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. Jones has an attic space that measures 23 feet by 48 feet. Our passive roof vents are ul certified and rated to withstand wind pressure in excess of 200 mph. 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 house measures 30 feet by 50 feet. Roof ventilation calculator enter your attic area or length and width to determine your ventilation needs. Calculate the soffit vent area needed divide the total vent area by two to determine the soffit vent area. Width or area.

Select ventilation product flex roll ridge vent multi roll multi purpose vent rigid roll ridge. There should also be a 50 50 balance of attic venting and roof venting. See quantities below for each gaf ventilation product typically rounded up. According to their requirements you should have 1 square foot of attic ventilation per 300 sq ft of attic floor space.

Calculate the total vent area needed multiply the length of the attic times the width in feet to find the attic area. Jones takes this measurement and divides it by 150 for a total of 7 36 square feet of ventilation space that is needed. This yields a total area of 1 104 square feet. Hence you would need two square feet 600 300 of attic ventilation.

Enter the length and width of the attic floor or the total square footage of the attic floor. Hit the calculate button for the recommended amount of exhaust and intake ventilation. Calculate or enter the square footage of the attic or area to be vented. As an example in an attic that is 30 feet by 20 feet you would have 600 square feet of floor area.

If your roof is 1200 sq ft soffit floor space you will need 4 sq feet of roof ventilation.