Calculating Attic Volume

Ok so now we know the square footage of the attic area to be ventilated.

Calculating attic volume.

This calculator is to be used as an estimating tool only. Nfa is the unobstructed area through which air can pass through a vent usually measured in square inches. Measure the height of your attic in feet. Select if your roof is more flat of peaked.

Divide this number by two. Attic square footage 2 square inches of exhaust and square inches of intake net free area nfa needed. Use a tape measure to figure out the dimensions of your attic. Then click on calculate.

Measure the length of your attic in feet. For heating and air conditioning airflow or for other exhaust fan situations see our airflow calculator. Click the button to calculate the depth in inches and pounds of total insulation required for this job. Ventilation manufacturers assign an nfa value to the non motorized vents they make.

Measure the length and width of the attic floor space to be ventilated. Calculate or enter the square footage of the attic or area to be vented. Enter the length and width of your attic or ceiling crawl space. How to calculate the cubic feet of an attic.

See how simple that was. Whether you plan on improving the ventilation in your attic or adding energy saving insulation you will need to accurately determine its actual size. In our case the required 4 vents for the 1200 sq ft house multiply the 144 cubic inches by 4 576 cubic inches. 1 500 square feet 300 5 square feet.

Remember the minimum area requirement when using a continuous system is a ratio of 1 300. Now let s figure out how much ventilation space we need. Then enter the height at the highest point. Measure the width of your attic in feet.

In order to find the right calculator divide the attic floor space by 300 sq feet. Make sure to measure in the center at the attic s highest point. Square footage relates to the floor area only and does not factor in the height of the attic space. 1 cubic foot is 12 x 12 144 cubic inches.

So in our example we will divide the 1 500 square feet by 300. Input length width and desired r value of the area to be insulated.