How Many Attic Vents Do I Need

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

How many attic vents do i need.

Building codes typically echo the administration s guidelines. And this guideline you ll need a minimum of. How many vents will my house need. 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.

Hvi recommends a ratio of 60 to 40 for soffit ventilation to gable or ridge ventilation. In order to facilitate this exchange of warm and cool air the general rule of thumb suggests installing at least 1 sq. The general rule is that you must have one square foot of vent space for every 150 square feet of attic area. Of vent for every 300 sq.

You need 6 66 square feet of attic ventilation. Since you want a balanced system you divide by 2 so that half of the ventilation is intake and half is exhaust. Always have a balanced ventilation system. For a home with 2000 square feet of attic floor space you ll first divide 2000 by 300 2000 300 6 66.

The downside of attic ventilation fans. The federal housing administration recommends 1 square foot of attic ventilation for every 150 square feet of attic space. In no case should the amount of exhaust ventilation exceed the amount of intake ventilation. 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.

Based on your 1100 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. As a general rule your roof needs 1 square foot of vent area for every 150 square feet of attic space. Thus if your attic is 450 square feet you need roof vents equaling 3 square feet.

To determine the total vent area measure the length and width of your attic in feet then multiply the two measurements to get the attic area then divide the number by 150 to get the vent space in square feet length x width 150.