Eave Input Vent Area To Floor Square Ft Ratio

30 feet x 50 feet 1 500 square feet.

Eave input vent area to floor square ft ratio.

1 square foot of nfva per 300 square feet of attic floor if a vapor barrier is installed on the ceiling below. Now let s figure out how much ventilation space we need. And this guideline you ll need a minimum of. This is distributed between under eave net free vent area and the ridge in a ratio of 60 under eave and 40 in the ridge.

This ratio is required for modern insulated homes. Based on your 1100 sq. Calculate or enter the square footage of the attic or area to be vented. Once attic square footage is known divide by 150 for the 1 150 ratio.

For example a single story house with 2000 square foot of roof floor area would require 13 3 square feet or 1920 square inches of vent area. 30 lineal feet required. The next step is to select a suitable exhaust vent and intake vent that fits the roof design for best performance and best aesthetics. 1 500 square feet.

So in our example we will divide the 1 500 square feet by 300. 2 200 2 1 100 square inches of exhaust net free area needed. 40 x 25 1 000 square feet of attic area 2. In no case should the amount of exhaust ventilation exceed the amount of intake ventilation.

Ventsure 4 foot strip heat moisture ridge vent with weather protector moisture barrier. Divide the square footage by 150 to calculate the area of ventilation needed since you need 1 square foot of vent space for each 150 square feet of attic space. A 6 x 12 vent would equal 72 sq. Ok so now we know the square footage of the attic area to be ventilated.

Say the contractor is standing in front of a house that has an attic with 2 200 square feet. Always have a balanced ventilation system. If you have 3 000 square feet of attic space this equates to 20 square feet of ventilation needed. For round vents multiply the radius of the vent half the diameter times itself squared then multiply the total by 3 14 pi and divide by 144 to find the number of square feet r in inches x 3 14 144 sq.

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. 1 100 square inches of intake net free area needed. Remember the minimum area requirement when using a continuous system is a ratio of 1 300. That determines the total amount of net free area needed to properly ventilate the attic.

In divided by 144 equals an area of 0 5 sq.