For a ventilation-area calculation, a design specifies 1 square foot of net free vent area per 300 square feet of attic area. An attic is 1,200 square feet. What net free vent area does this specified ratio require?
- 4 square feet
- B8 square feet
- C12 square feet
- D16 square feet
Where to look it up
Explicit exercise assumptions; not a universal code requirement.
Why A is correct
Divide the attic area by the specified ratio denominator: 1,200 ÷ 300 = 4 square feet of net free vent area. This exercise does not establish whether the 1:300 ratio is permitted for a particular attic or how vents must be distributed.