For years we have been working with Architects and Specifiers to ensure affordable roof ventilation that upholds building code standards. Our passive roof vents are UL Certified, and rated to withstand wind pressure in excess of 200 mph.

Use AVP’s Roof Vent Calculator to determine the number and size of exhaust vents you will need.


For balanced ventilation, an equal amount of intake vent area (“Net Free Area”) should also be installed. Our Soffit VentsRound Back VentsPop Vents, and Universal Vents make excellent intake vents.  

architects and specifiers - resources
You do not need to go back to school to understand the building science behind roof ventilation “The basic breakdown”
Home owners and professionals alike have questions and concerns about how to properly ventilate their roof. Which roof vents are best based on roof type, climate, and budget for example: We want to share those questions and answers with you.
Question: What are the building code requirements for ventilating a roof?
Answer: 1 square foot of ventilation for every 300 square feet of space for pitched roofs with vapor barriers 1 square foot of ventilation for every 150 square feet of space no vapor barrier and for some municipalities in hot climates

Example Building

1,000 Divided by 300 = 3.33 Total Square Feet. 50% Intake 1.7 Sq. Ft. & 50% Exhaust 1.7 Sq. Ft 1,000 Divided by 150 = 6.66 Total Square Feet 50% Intake 3.3 Sq. Ft. & 50% Exhaust 3.3 Sq. Ft.

Rendered 3D flat roof building, 20 ft wide x 50 ft long.

Choose Vent Line to Calculate

Choose Vent to Calculate

Enter the Width and Length of the attic space you need to ventilate to calculate the area. You may also enter the area directly in the "Area" field.

Pull down to select a specific vent diameter to see how many vents of that size would ventilate the specified area.

No Vent Line Yet Chosen - Select Above

The roof vent calculation values shown above are for the exhaust portion of the roof. The same amount of net free air inches is needed for air intake as well. Proper roof ventilation consists of 50% air exhaust and 50% air intake.

Copyright Active Ventilation Products, Inc. 2021 - All Rights Reserved
linkedin facebook pinterest youtube rss twitter instagram facebook-blank rss-blank linkedin-blank pinterest youtube twitter instagram