According to the home ventilating institute hvi powered attic ventilators need to move a minimum of 700 cubic feet per minute cfm for 1 000 sq.
Attic aiir vent neede.
Ft you divide that by 150 to get 10 sq.
Without exception you should talk to a professional to determine what your home requires.
Generally speaking you need a ratio of 1 300 where for every 300 square feet of ceiling space you need 1 square foot of attic ventilation.
Attic ventilation works on the principle that heated air naturally rises primarily utilizing two types of vents.
Intake vents located at the lowest part of the roof under the eaves allow cool.
The rule of thumb on the amount of vent space needed is approximately 1 sq.
Ventsure inflow intake vent.
Tips for assessing your needs.
The ventilation that controls moisture from condensation and regulates the temperature in your attic relies on air circulation.
Jones has an attic space that measures 23 feet by 48 feet.
That said air resistance and interference such as vent grates reduces the area of true ventilation.
The following product options will allow you to achieve an intake nfva of 528 square inches.
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.
Allows cool dry air to enter the attic.
Since 1996 attic air has earned a reputation for providing effective solutions for your insulation and ventilation needs.
Jones takes this measurement and divides it by 150 for a total of 7 36 square feet of ventilation space that is needed.
To lower attic temperatures and to remove excess moisture.
Lowering the temperature in the attic can help reduce air conditioning energy costs and roof deck temperature optimize the service life of a roof covering and minimize ice damming.
In a properly designed passive system air enters through the soffit.
So if your attic is 1 500 sq.
Proper attic ventilation consists of a balance between air intake at your eaves soffits or fascias and air exhaust at or near your roof ridge.
Of vent space for every 150 sq.
Choose one of the following products to meet the recommended intake nfva of 528 square inches.
Attic ventilation serves two main functions.
Ideally there should also be plenty of soffit intake space their calculations recommend 336 net square inches of open soffit ventilation to supply 700 cfm.