Attic Venting Requirements

Attic venting requirements your airscape needs to breathe a whole house fan is designed to move air from your house into your attic.

Attic venting requirements.

To lower attic temperatures and to remove excess moisture. I was told there would be no math. Balance is the key. What does the code require.

As an example in an attic that is 30 feet by 20 feet you would have 600 square feet of floor area. Vents are rated by their net free area or the amount of space for air to flow in or out. Measure the length and width of the attic floor space to be ventilated. Lines for attic ventilation.

And since just about all attics are vented the pressurized attic air is then naturally pushed outside through those vents. The net free vent area nfva shall not be less than 1 150 of the area of the space being vented. Ventilation of attic spaces is required by most building codes as well as by roofing material manufacturers and the national roofing contractors association nrca. You can calculate attic ventilation requirements by determining the square footage of your attic floor its width times its length and compare that to the total required net free area nfa.

You can also contact your local municipality to check on building code in your area. The ideal roof attic ventilation would consists of combination of vents located in upper section of the attic ridge vents turbine box shaped or dome static vents electric motor powered vents vents installed along the bottom parts of the roof overhang called intake or soffit vents hip vents and or gable vents all of the provided links are just samples vents manufactured by one company. Hence you would need two square feet 600 300 of attic ventilation. Attic ventilation serves two main functions.

In order to facilitate this exchange of warm and cool air the general rule of thumb suggests installing at least 1 sq. Enter your square footage. According to the fha federal housing administration us for every 300 square feet of attic floor area you should have at minimum one square foot ventilation. Of vent for every 300 sq.

Most building codes require a ratio of 1 150 ventilation space to attic floor space.