Free Air For Roof Vent

Choose one of the following products to meet the recommended exhaust nfva of 528 square inches.

Free air for roof vent.

This shortcut conveniently calculates the 2015 international residential building code minimum irc section r806 roof ventilation 1 which states in part 1 square foot of net free area for every 150 square feet of attic floor space with the attic defined as length x width floor of the attic. The two rectangles formed between the cap shingle and roof deck offer 18 square inches of open area for air to flow. The following product options will allow you to achieve an intake nfva of 528 square inches. The idea of roof vents existed for hundreds of years with natural vents employed in chinese buildings during the tang dynasty natural ventilation ducts in the buddhist monks caves and wind catchers incorporated in arabian architecture.

Free shipping and free returns on prime eligible items. Air vent 53827 roof mounted power attic ventilator brown. They are typically easier to install and won t detract from the appearance of your roof. Allows cool dry air to enter the attic.

The nfa is the open area that exists for air to pass through. Ventsure 4 foot strip heat moisture ridge vent. Venting products are normally rated with a net free area nfa. They can quickly remove a larger volume of hot and or humid air from your attic compared to static ventilation which helps save money on your heating and cooling costs.

But the fibers in the vent media reduce the open area so the actual net free area is 15 2 square inches per linear foot. Vent roofs with steeples towers or cupolas can be found in different buildings from barns to cathedrals. When you are planning your attic ventilation system you should have at least one square foot of net free ventilation area for every 150 feet of attic space measured at the attic floor level. The key to effective venting is to balance air intake at your eaves soffits or fascias and air exhaust at or near your roof ridge.

Ideally the nfa of the soffits should be equal or greater than that of the ridge vent and in no case should the amount of exhaust ventilation exceed the amount of intake ventilation. There should also be at least one inch of air space between any insulation or obstruction and roof sheathing. The building codes and building science for.