How Many Attic Vents Do I Need

And this guideline you ll need a minimum of.

How many attic vents do i need.

In no case should the amount of exhaust ventilation exceed the amount of intake ventilation. Always have a balanced ventilation system. Based on your 1100 sq. Of vent for every 300 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. You need 6 66 square feet of attic ventilation. Federal housing authority recommends a minimum of at least 1 square foot of attic ventilation for every 300 square feet of attic floor space evenly split between intake and exhaust. Since you want a balanced system you divide by 2 so that half of the ventilation is intake and half is exhaust.

In order to facilitate this exchange of warm and cool air the general rule of thumb suggests installing at least 1 sq. Attic ventilation fans whether hard wired or powered by their own solar panels seem like a low cost and effective way to help keep your house cool. Building codes typically echo the administration s guidelines. They should be divided equally between inlet and outlet vents and they can be used in any combination that will work with your roof s design.

The downside of attic ventilation fans. If your attic floor has a vapor barrier you will need one square foot of nfa per every 300 square feet of attic floor area half of that will be intake half for exhaust. For a home with 2000 square feet of attic floor space you ll first divide 2000 by 300 2000 300 6 66. Hvi recommends a ratio of 60 to 40 for soffit ventilation to gable or ridge ventilation.

The general rule is that you must have one square foot of vent space for every 150 square feet of attic area. The federal housing administration recommends 1 square foot of attic ventilation for every 150 square feet of attic space. Thus if your attic is 450 square feet you need roof vents equaling 3 square feet. As a general rule your roof needs 1 square foot of vent area for every 150 square feet of attic space.

This helps make it easy to calculate how many vents you need for your attic once you ve determined your requirements.